test_dbapi.py

# pysqlite2/test/dbapi.py: tests for DB-API compliance
#
# Copyright (C) 2004-2010 Gerhard Häring <gh@ghaering.de>
#
# This file is part of pysqlite.
#
# This software is provided 'as-is', without any express or implied
# warranty.  In no event will the authors be held liable for any damages
# arising from the use of this software.
#
# Permission is granted to anyone to use this software for any purpose,
# including commercial applications, and to alter it and redistribute it
# freely, subject to the following restrictions:
#
# 1. The origin of this software must not be misrepresented; you must not
#    claim that you wrote the original software. If you use this software
#    in a product, an acknowledgment in the product documentation would be
#    appreciated but is not required.
# 2. Altered source versions must be plainly marked as such, and must not be
#    misrepresented as being the original software.
# 3. This notice may not be removed or altered from any source distribution.

import contextlib
import functools
import os
import sqlite3 as sqlite
import subprocess
import sys
import threading
import unittest
import urllib.parse
import warnings

from test.support import (
    SHORT_TIMEOUT, check_disallow_instantiation, requires_subprocess
)
from test.support import gc_collect
from test.support import threading_helper, import_helper
from os import SEEK_SET, SEEK_CUR, SEEK_END
from test.support.os_helper import TESTFN, TESTFN_UNDECODABLE, unlink, temp_dir, FakePath

from .util import memory_database, cx_limit
from .util import MemoryDatabaseMixin


class ModuleTests(unittest.TestCase):
    def test_api_level(self):
        self.assertEqual(sqlite.apilevel, "2.0",
                         "apilevel is %s, should be 2.0" % sqlite.apilevel)

    def test_deprecated_version(self):
        msg = "deprecated and will be removed in Python 3.14"
        for attr in "version", "version_info":
            with self.subTest(attr=attr):
                with self.assertWarnsRegex(DeprecationWarning, msg) as cm:
                    getattr(sqlite, attr)
                self.assertEqual(cm.filename,  __file__)
                with self.assertWarnsRegex(DeprecationWarning, msg) as cm:
                    getattr(sqlite.dbapi2, attr)
                self.assertEqual(cm.filename,  __file__)

    def test_thread_safety(self):
        self.assertIn(sqlite.threadsafety, {0, 1, 3},
                      "threadsafety is %d, should be 0, 1 or 3" %
                      sqlite.threadsafety)

    def test_param_style(self):
        self.assertEqual(sqlite.paramstyle, "qmark",
                         "paramstyle is '%s', should be 'qmark'" %
                         sqlite.paramstyle)

    def test_warning(self):
        self.assertTrue(issubclass(sqlite.Warning, Exception),
                     "Warning is not a subclass of Exception")

    def test_error(self):
        self.assertTrue(issubclass(sqlite.Error, Exception),
                        "Error is not a subclass of Exception")

    def test_interface_error(self):
        self.assertTrue(issubclass(sqlite.InterfaceError, sqlite.Error),
                        "InterfaceError is not a subclass of Error")

    def test_database_error(self):
        self.assertTrue(issubclass(sqlite.DatabaseError, sqlite.Error),
                        "DatabaseError is not a subclass of Error")

    def test_data_error(self):
        self.assertTrue(issubclass(sqlite.DataError, sqlite.DatabaseError),
                        "DataError is not a subclass of DatabaseError")

    def test_operational_error(self):
        self.assertTrue(issubclass(sqlite.OperationalError, sqlite.DatabaseError),
                        "OperationalError is not a subclass of DatabaseError")

    def test_integrity_error(self):
        self.assertTrue(issubclass(sqlite.IntegrityError, sqlite.DatabaseError),
                        "IntegrityError is not a subclass of DatabaseError")

    def test_internal_error(self):
        self.assertTrue(issubclass(sqlite.InternalError, sqlite.DatabaseError),
                        "InternalError is not a subclass of DatabaseError")

    def test_programming_error(self):
        self.assertTrue(issubclass(sqlite.ProgrammingError, sqlite.DatabaseError),
                        "ProgrammingError is not a subclass of DatabaseError")

    def test_not_supported_error(self):
        self.assertTrue(issubclass(sqlite.NotSupportedError,
                                   sqlite.DatabaseError),
                        "NotSupportedError is not a subclass of DatabaseError")

    def test_module_constants(self):
        consts = [
            "SQLITE_ABORT",
            "SQLITE_ALTER_TABLE",
            "SQLITE_ANALYZE",
            "SQLITE_ATTACH",
            "SQLITE_AUTH",
            "SQLITE_BUSY",
            "SQLITE_CANTOPEN",
            "SQLITE_CONSTRAINT",
            "SQLITE_CORRUPT",
            "SQLITE_CREATE_INDEX",
            "SQLITE_CREATE_TABLE",
            "SQLITE_CREATE_TEMP_INDEX",
            "SQLITE_CREATE_TEMP_TABLE",
            "SQLITE_CREATE_TEMP_TRIGGER",
            "SQLITE_CREATE_TEMP_VIEW",
            "SQLITE_CREATE_TRIGGER",
            "SQLITE_CREATE_VIEW",
            "SQLITE_CREATE_VTABLE",
            "SQLITE_DELETE",
            "SQLITE_DENY",
            "SQLITE_DETACH",
            "SQLITE_DONE",
            "SQLITE_DROP_INDEX",
            "SQLITE_DROP_TABLE",
            "SQLITE_DROP_TEMP_INDEX",
            "SQLITE_DROP_TEMP_TABLE",
            "SQLITE_DROP_TEMP_TRIGGER",
            "SQLITE_DROP_TEMP_VIEW",
            "SQLITE_DROP_TRIGGER",
            "SQLITE_DROP_VIEW",
            "SQLITE_DROP_VTABLE",
            "SQLITE_EMPTY",
            "SQLITE_ERROR",
            "SQLITE_FORMAT",
            "SQLITE_FULL",
            "SQLITE_FUNCTION",
            "SQLITE_IGNORE",
            "SQLITE_INSERT",
            "SQLITE_INTERNAL",
            "SQLITE_INTERRUPT",
            "SQLITE_IOERR",
            "SQLITE_LIMIT_WORKER_THREADS",
            "SQLITE_LOCKED",
            "SQLITE_MISMATCH",
            "SQLITE_MISUSE",
            "SQLITE_NOLFS",
            "SQLITE_NOMEM",
            "SQLITE_NOTADB",
            "SQLITE_NOTFOUND",
            "SQLITE_NOTICE",
            "SQLITE_OK",
            "SQLITE_PERM",
            "SQLITE_PRAGMA",
            "SQLITE_PROTOCOL",
            "SQLITE_RANGE",
            "SQLITE_READ",
            "SQLITE_READONLY",
            "SQLITE_RECURSIVE",
            "SQLITE_REINDEX",
            "SQLITE_ROW",
            "SQLITE_SAVEPOINT",
            "SQLITE_SCHEMA",
            "SQLITE_SELECT",
            "SQLITE_TOOBIG",
            "SQLITE_TRANSACTION",
            "SQLITE_UPDATE",
            "SQLITE_WARNING",
            # Run-time limit categories
            "SQLITE_LIMIT_LENGTH",
            "SQLITE_LIMIT_SQL_LENGTH",
            "SQLITE_LIMIT_COLUMN",
            "SQLITE_LIMIT_EXPR_DEPTH",
            "SQLITE_LIMIT_COMPOUND_SELECT",
            "SQLITE_LIMIT_VDBE_OP",
            "SQLITE_LIMIT_FUNCTION_ARG",
            "SQLITE_LIMIT_ATTACHED",
            "SQLITE_LIMIT_LIKE_PATTERN_LENGTH",
            "SQLITE_LIMIT_VARIABLE_NUMBER",
            "SQLITE_LIMIT_TRIGGER_DEPTH",
        ]
        consts += ["PARSE_DECLTYPES", "PARSE_COLNAMES"]
        # Extended result codes
        consts += [
            "SQLITE_ABORT_ROLLBACK",
            "SQLITE_AUTH_USER",
            "SQLITE_BUSY_RECOVERY",
            "SQLITE_BUSY_SNAPSHOT",
            "SQLITE_CANTOPEN_CONVPATH",
            "SQLITE_CANTOPEN_FULLPATH",
            "SQLITE_CANTOPEN_ISDIR",
            "SQLITE_CANTOPEN_NOTEMPDIR",
            "SQLITE_CONSTRAINT_CHECK",
            "SQLITE_CONSTRAINT_COMMITHOOK",
            "SQLITE_CONSTRAINT_FOREIGNKEY",
            "SQLITE_CONSTRAINT_FUNCTION",
            "SQLITE_CONSTRAINT_NOTNULL",
            "SQLITE_CONSTRAINT_PRIMARYKEY",
            "SQLITE_CONSTRAINT_ROWID",
            "SQLITE_CONSTRAINT_TRIGGER",
            "SQLITE_CONSTRAINT_UNIQUE",
            "SQLITE_CONSTRAINT_VTAB",
            "SQLITE_CORRUPT_VTAB",
            "SQLITE_IOERR_ACCESS",
            "SQLITE_IOERR_AUTH",
            "SQLITE_IOERR_BLOCKED",
            "SQLITE_IOERR_CHECKRESERVEDLOCK",
            "SQLITE_IOERR_CLOSE",
            "SQLITE_IOERR_CONVPATH",
            "SQLITE_IOERR_DELETE",
            "SQLITE_IOERR_DELETE_NOENT",
            "SQLITE_IOERR_DIR_CLOSE",
            "SQLITE_IOERR_DIR_FSYNC",
            "SQLITE_IOERR_FSTAT",
            "SQLITE_IOERR_FSYNC",
            "SQLITE_IOERR_GETTEMPPATH",
            "SQLITE_IOERR_LOCK",
            "SQLITE_IOERR_MMAP",
            "SQLITE_IOERR_NOMEM",
            "SQLITE_IOERR_RDLOCK",
            "SQLITE_IOERR_READ",
            "SQLITE_IOERR_SEEK",
            "SQLITE_IOERR_SHMLOCK",
            "SQLITE_IOERR_SHMMAP",
            "SQLITE_IOERR_SHMOPEN",
            "SQLITE_IOERR_SHMSIZE",
            "SQLITE_IOERR_SHORT_READ",
            "SQLITE_IOERR_TRUNCATE",
            "SQLITE_IOERR_UNLOCK",
            "SQLITE_IOERR_VNODE",
            "SQLITE_IOERR_WRITE",
            "SQLITE_LOCKED_SHAREDCACHE",
            "SQLITE_NOTICE_RECOVER_ROLLBACK",
            "SQLITE_NOTICE_RECOVER_WAL",
            "SQLITE_OK_LOAD_PERMANENTLY",
            "SQLITE_READONLY_CANTLOCK",
            "SQLITE_READONLY_DBMOVED",
            "SQLITE_READONLY_RECOVERY",
            "SQLITE_READONLY_ROLLBACK",
            "SQLITE_WARNING_AUTOINDEX",
        ]
        if sqlite.sqlite_version_info >= (3, 21, 0):
            consts += [
                "SQLITE_IOERR_BEGIN_ATOMIC",
                "SQLITE_IOERR_COMMIT_ATOMIC",
                "SQLITE_IOERR_ROLLBACK_ATOMIC",
            ]
        if sqlite.sqlite_version_info >= (3, 22, 0):
            consts += [
                "SQLITE_ERROR_MISSING_COLLSEQ",
                "SQLITE_ERROR_RETRY",
                "SQLITE_READONLY_CANTINIT",
                "SQLITE_READONLY_DIRECTORY",
            ]
        if sqlite.sqlite_version_info >= (3, 24, 0):
            consts += ["SQLITE_CORRUPT_SEQUENCE", "SQLITE_LOCKED_VTAB"]
        if sqlite.sqlite_version_info >= (3, 25, 0):
            consts += ["SQLITE_CANTOPEN_DIRTYWAL", "SQLITE_ERROR_SNAPSHOT"]
        if sqlite.sqlite_version_info >= (3, 31, 0):
            consts += [
                "SQLITE_CANTOPEN_SYMLINK",
                "SQLITE_CONSTRAINT_PINNED",
                "SQLITE_OK_SYMLINK",
            ]
        if sqlite.sqlite_version_info >= (3, 32, 0):
            consts += [
                "SQLITE_BUSY_TIMEOUT",
                "SQLITE_CORRUPT_INDEX",
                "SQLITE_IOERR_DATA",
            ]
        if sqlite.sqlite_version_info >= (3, 34, 0):
            consts.append("SQLITE_IOERR_CORRUPTFS")
        for const in consts:
            with self.subTest(const=const):
                self.assertTrue(hasattr(sqlite, const))

    def test_error_code_on_exception(self):
        err_msg = "unable to open database file"
        if sys.platform.startswith("win"):
            err_code = sqlite.SQLITE_CANTOPEN_ISDIR
        else:
            err_code = sqlite.SQLITE_CANTOPEN

        with temp_dir() as db:
            with self.assertRaisesRegex(sqlite.Error, err_msg) as cm:
                sqlite.connect(db)
            e = cm.exception
            self.assertEqual(e.sqlite_errorcode, err_code)
            self.assertTrue(e.sqlite_errorname.startswith("SQLITE_CANTOPEN"))

    def test_extended_error_code_on_exception(self):
        with memory_database() as con:
            with con:
                con.execute("create table t(t integer check(t > 0))")
            errmsg = "constraint failed"
            with self.assertRaisesRegex(sqlite.IntegrityError, errmsg) as cm:
                con.execute("insert into t values(-1)")
            exc = cm.exception
            self.assertEqual(exc.sqlite_errorcode,
                             sqlite.SQLITE_CONSTRAINT_CHECK)
            self.assertEqual(exc.sqlite_errorname, "SQLITE_CONSTRAINT_CHECK")

    def test_disallow_instantiation(self):
        with memory_database() as cx:
            check_disallow_instantiation(self, type(cx("select 1")))
            check_disallow_instantiation(self, sqlite.Blob)

    def test_complete_statement(self):
        self.assertFalse(sqlite.complete_statement("select t"))
        self.assertTrue(sqlite.complete_statement("create table t(t);"))


class ConnectionTests(unittest.TestCase):

    def setUp(self):
        self.cx = sqlite.connect(":memory:")
        cu = self.cx.cursor()
        cu.execute("create table test(id integer primary key, name text)")
        cu.execute("insert into test(name) values (?)", ("foo",))
        cu.close()

    def tearDown(self):
        self.cx.close()

    def test_commit(self):
        self.cx.commit()

    def test_commit_after_no_changes(self):
        """
        A commit should also work when no changes were made to the database.
        """
        self.cx.commit()
        self.cx.commit()

    def test_rollback(self):
        self.cx.rollback()

    def test_rollback_after_no_changes(self):
        """
        A rollback should also work when no changes were made to the database.
        """
        self.cx.rollback()
        self.cx.rollback()

    def test_cursor(self):
        cu = self.cx.cursor()

    def test_failed_open(self):
        YOU_CANNOT_OPEN_THIS = "/foo/bar/bla/23534/mydb.db"
        with self.assertRaises(sqlite.OperationalError):
            sqlite.connect(YOU_CANNOT_OPEN_THIS)

    def test_close(self):
        self.cx.close()

    def test_use_after_close(self):
        sql = "select 1"
        cu = self.cx.cursor()
        res = cu.execute(sql)
        self.cx.close()
        self.assertRaises(sqlite.ProgrammingError, res.fetchall)
        self.assertRaises(sqlite.ProgrammingError, cu.execute, sql)
        self.assertRaises(sqlite.ProgrammingError, cu.executemany, sql, [])
        self.assertRaises(sqlite.ProgrammingError, cu.executescript, sql)
        self.assertRaises(sqlite.ProgrammingError, self.cx.execute, sql)
        self.assertRaises(sqlite.ProgrammingError,
                          self.cx.executemany, sql, [])
        self.assertRaises(sqlite.ProgrammingError, self.cx.executescript, sql)
        self.assertRaises(sqlite.ProgrammingError,
                          self.cx.create_function, "t", 1, lambda x: x)
        self.assertRaises(sqlite.ProgrammingError, self.cx.cursor)
        with self.assertRaises(sqlite.ProgrammingError):
            with self.cx:
                pass

    def test_exceptions(self):
        # Optional DB-API extension.
        self.assertEqual(self.cx.Warning, sqlite.Warning)
        self.assertEqual(self.cx.Error, sqlite.Error)
        self.assertEqual(self.cx.InterfaceError, sqlite.InterfaceError)
        self.assertEqual(self.cx.DatabaseError, sqlite.DatabaseError)
        self.assertEqual(self.cx.DataError, sqlite.DataError)
        self.assertEqual(self.cx.OperationalError, sqlite.OperationalError)
        self.assertEqual(self.cx.IntegrityError, sqlite.IntegrityError)
        self.assertEqual(self.cx.InternalError, sqlite.InternalError)
        self.assertEqual(self.cx.ProgrammingError, sqlite.ProgrammingError)
        self.assertEqual(self.cx.NotSupportedError, sqlite.NotSupportedError)

    def test_in_transaction(self):
        # Can't use db from setUp because we want to test initial state.
        with memory_database() as cx:
            cu = cx.cursor()
            self.assertEqual(cx.in_transaction, False)
            cu.execute("create table transactiontest(id integer primary key, name text)")
            self.assertEqual(cx.in_transaction, False)
            cu.execute("insert into transactiontest(name) values (?)", ("foo",))
            self.assertEqual(cx.in_transaction, True)
            cu.execute("select name from transactiontest where name=?", ["foo"])
            row = cu.fetchone()
            self.assertEqual(cx.in_transaction, True)
            cx.commit()
            self.assertEqual(cx.in_transaction, False)
            cu.execute("select name from transactiontest where name=?", ["foo"])
            row = cu.fetchone()
            self.assertEqual(cx.in_transaction, False)
            cu.close()

    def test_in_transaction_ro(self):
        with self.assertRaises(AttributeError):
            self.cx.in_transaction = True

    def test_connection_exceptions(self):
        exceptions = [
            "DataError",
            "DatabaseError",
            "Error",
            "IntegrityError",
            "InterfaceError",
            "NotSupportedError",
            "OperationalError",
            "ProgrammingError",
            "Warning",
        ]
        for exc in exceptions:
            with self.subTest(exc=exc):
                self.assertTrue(hasattr(self.cx, exc))
                self.assertIs(getattr(sqlite, exc), getattr(self.cx, exc))

    def test_interrupt_on_closed_db(self):
        self.cx.close()
        with self.assertRaises(sqlite.ProgrammingError):
            self.cx.interrupt()

    def test_interrupt(self):
        self.assertIsNone(self.cx.interrupt())

    def test_drop_unused_refs(self):
        for n in range(500):
            cu = self.cx.execute(f"select {n}")
            self.assertEqual(cu.fetchone()[0], n)

    def test_connection_limits(self):
        category = sqlite.SQLITE_LIMIT_SQL_LENGTH
        saved_limit = self.cx.getlimit(category)
        try:
            new_limit = 10
            prev_limit = self.cx.setlimit(category, new_limit)
            self.assertEqual(saved_limit, prev_limit)
            self.assertEqual(self.cx.getlimit(category), new_limit)
            msg = "query string is too large"
            self.assertRaisesRegex(sqlite.DataError, msg,
                                   self.cx.execute, "select 1 as '16'")
        finally:  # restore saved limit
            self.cx.setlimit(category, saved_limit)

    def test_connection_bad_limit_category(self):
        msg = "'category' is out of bounds"
        cat = 1111
        self.assertRaisesRegex(sqlite.ProgrammingError, msg,
                               self.cx.getlimit, cat)
        self.assertRaisesRegex(sqlite.ProgrammingError, msg,
                               self.cx.setlimit, cat, 0)

    def test_connection_init_bad_isolation_level(self):
        msg = (
            "isolation_level string must be '', 'DEFERRED', 'IMMEDIATE', or "
            "'EXCLUSIVE'"
        )
        levels = (
            "BOGUS",
            " ",
            "DEFERRE",
            "IMMEDIAT",
            "EXCLUSIV",
            "DEFERREDS",
            "IMMEDIATES",
            "EXCLUSIVES",
        )
        for level in levels:
            with self.subTest(level=level):
                with self.assertRaisesRegex(ValueError, msg):
                    memory_database(isolation_level=level)
                with memory_database() as cx:
                    with self.assertRaisesRegex(ValueError, msg):
                        cx.isolation_level = level
                    # Check that the default level is not changed
                    self.assertEqual(cx.isolation_level, "")

    def test_connection_init_good_isolation_levels(self):
        for level in ("", "DEFERRED", "IMMEDIATE", "EXCLUSIVE", None):
            with self.subTest(level=level):
                with memory_database(isolation_level=level) as cx:
                    self.assertEqual(cx.isolation_level, level)
                with memory_database() as cx:
                    self.assertEqual(cx.isolation_level, "")
                    cx.isolation_level = level
                    self.assertEqual(cx.isolation_level, level)

    def test_connection_reinit(self):
        with memory_database() as cx:
            cx.text_factory = bytes
            cx.row_factory = sqlite.Row
            cu = cx.cursor()
            cu.execute("create table foo (bar)")
            cu.executemany("insert into foo (bar) values (?)",
                           ((str(v),) for v in range(4)))
            cu.execute("select bar from foo")

            rows = [r for r in cu.fetchmany(2)]
            self.assertTrue(all(isinstance(r, sqlite.Row) for r in rows))
            self.assertEqual([r[0] for r in rows], [b"0", b"1"])

            cx.__init__(":memory:")
            cx.execute("create table foo (bar)")
            cx.executemany("insert into foo (bar) values (?)",
                           ((v,) for v in ("a", "b", "c", "d")))

            # This uses the old database, old row factory, but new text factory
            rows = [r for r in cu.fetchall()]
            self.assertTrue(all(isinstance(r, sqlite.Row) for r in rows))
            self.assertEqual([r[0] for r in rows], ["2", "3"])
            cu.close()

    def test_connection_bad_reinit(self):
        cx = sqlite.connect(":memory:")
        with cx:
            cx.execute("create table t(t)")
        with temp_dir() as db:
            self.assertRaisesRegex(sqlite.OperationalError,
                                   "unable to open database file",
                                   cx.__init__, db)
            self.assertRaisesRegex(sqlite.ProgrammingError,
                                   "Base Connection.__init__ not called",
                                   cx.executemany, "insert into t values(?)",
                                   ((v,) for v in range(3)))

    def test_connection_config(self):
        op = sqlite.SQLITE_DBCONFIG_ENABLE_FKEY
        with memory_database() as cx:
            with self.assertRaisesRegex(ValueError, "unknown"):
                cx.getconfig(-1)

            # Toggle and verify.
            old = cx.getconfig(op)
            new = not old
            cx.setconfig(op, new)
            self.assertEqual(cx.getconfig(op), new)

            cx.setconfig(op)  # defaults to True
            self.assertTrue(cx.getconfig(op))

            # Check that foreign key support was actually enabled.
            with cx:
                cx.executescript("""
                    create table t(t integer primary key);
                    create table u(u, foreign key(u) references t(t));
                """)
            with self.assertRaisesRegex(sqlite.IntegrityError, "constraint"):
                cx.execute("insert into u values(0)")

    def test_connect_positional_arguments(self):
        regex = (
            r"Passing more than 1 positional argument to sqlite3.connect\(\)"
            " is deprecated. Parameters 'timeout', 'detect_types', "
            "'isolation_level', 'check_same_thread', 'factory', "
            "'cached_statements' and 'uri' will become keyword-only "
            "parameters in Python 3.15."
        )
        with self.assertWarnsRegex(DeprecationWarning, regex) as cm:
            cx = sqlite.connect(":memory:", 1.0)
            cx.close()
        self.assertEqual(cm.filename, __file__)

    def test_connection_resource_warning(self):
        with self.assertWarns(ResourceWarning):
            cx = sqlite.connect(":memory:")
            del cx
            gc_collect()

    def test_connection_signature(self):
        from inspect import signature
        sig = signature(self.cx)
        self.assertEqual(str(sig), "(sql, /)")


class UninitialisedConnectionTests(unittest.TestCase):
    def setUp(self):
        self.cx = sqlite.Connection.__new__(sqlite.Connection)

    def test_uninit_operations(self):
        funcs = (
            lambda: self.cx.isolation_level,
            lambda: self.cx.total_changes,
            lambda: self.cx.in_transaction,
            lambda: self.cx.iterdump(),
            lambda: self.cx.cursor(),
            lambda: self.cx.close(),
        )
        for func in funcs:
            with self.subTest(func=func):
                self.assertRaisesRegex(sqlite.ProgrammingError,
                                       "Base Connection.__init__ not called",
                                       func)


@unittest.skipUnless(hasattr(sqlite.Connection, "serialize"),
                     "Needs SQLite serialize API")
class SerializeTests(unittest.TestCase):
    def test_serialize_deserialize(self):
        with memory_database() as cx:
            with cx:
                cx.execute("create table t(t)")
            data = cx.serialize()

            # Remove test table, verify that it was removed.
            with cx:
                cx.execute("drop table t")
            regex = "no such table"
            with self.assertRaisesRegex(sqlite.OperationalError, regex):
                cx.execute("select t from t")

            # Deserialize and verify that test table is restored.
            cx.deserialize(data)
            cx.execute("select t from t")

    def test_deserialize_wrong_args(self):
        dataset = (
            (BufferError, memoryview(b"blob")[::2]),
            (TypeError, []),
            (TypeError, 1),
            (TypeError, None),
        )
        for exc, arg in dataset:
            with self.subTest(exc=exc, arg=arg):
                with memory_database() as cx:
                    self.assertRaises(exc, cx.deserialize, arg)

    def test_deserialize_corrupt_database(self):
        with memory_database() as cx:
            regex = "file is not a database"
            with self.assertRaisesRegex(sqlite.DatabaseError, regex):
                cx.deserialize(b"\0\1\3")
                # SQLite does not generate an error until you try to query the
                # deserialized database.
                cx.execute("create table fail(f)")


class OpenTests(unittest.TestCase):
    _sql = "create table test(id integer)"

    def test_open_with_bytes_path(self):
        path = os.fsencode(TESTFN)
        self.addCleanup(unlink, path)
        self.assertFalse(os.path.exists(path))
        with contextlib.closing(sqlite.connect(path)) as cx:
            self.assertTrue(os.path.exists(path))
            cx.execute(self._sql)

    def test_open_with_path_like_object(self):
        """ Checks that we can successfully connect to a database using an object that
            is PathLike, i.e. has __fspath__(). """
        path = FakePath(TESTFN)
        self.addCleanup(unlink, path)
        self.assertFalse(os.path.exists(path))
        with contextlib.closing(sqlite.connect(path)) as cx:
            self.assertTrue(os.path.exists(path))
            cx.execute(self._sql)

    def get_undecodable_path(self):
        path = TESTFN_UNDECODABLE
        if not path:
            self.skipTest("only works if there are undecodable paths")
        try:
            open(path, 'wb').close()
        except OSError:
            self.skipTest(f"can't create file with undecodable path {path!r}")
        unlink(path)
        return path

    @unittest.skipIf(sys.platform == "win32", "skipped on Windows")
    def test_open_with_undecodable_path(self):
        path = self.get_undecodable_path()
        self.addCleanup(unlink, path)
        with contextlib.closing(sqlite.connect(path)) as cx:
            self.assertTrue(os.path.exists(path))
            cx.execute(self._sql)

    def test_open_uri(self):
        path = TESTFN
        self.addCleanup(unlink, path)
        uri = "file:" + urllib.parse.quote(os.fsencode(path))
        self.assertFalse(os.path.exists(path))
        with contextlib.closing(sqlite.connect(uri, uri=True)) as cx:
            self.assertTrue(os.path.exists(path))
            cx.execute(self._sql)

    def test_open_unquoted_uri(self):
        path = TESTFN
        self.addCleanup(unlink, path)
        uri = "file:" + path
        self.assertFalse(os.path.exists(path))
        with contextlib.closing(sqlite.connect(uri, uri=True)) as cx:
            self.assertTrue(os.path.exists(path))
            cx.execute(self._sql)

    def test_open_uri_readonly(self):
        path = TESTFN
        self.addCleanup(unlink, path)
        uri = "file:" + urllib.parse.quote(os.fsencode(path)) + "?mode=ro"
        self.assertFalse(os.path.exists(path))
        # Cannot create new DB
        with self.assertRaises(sqlite.OperationalError):
            sqlite.connect(uri, uri=True)
        self.assertFalse(os.path.exists(path))
        sqlite.connect(path).close()
        self.assertTrue(os.path.exists(path))
        # Cannot modify new DB
        with contextlib.closing(sqlite.connect(uri, uri=True)) as cx:
            with self.assertRaises(sqlite.OperationalError):
                cx.execute(self._sql)

    @unittest.skipIf(sys.platform == "win32", "skipped on Windows")
    def test_open_undecodable_uri(self):
        path = self.get_undecodable_path()
        self.addCleanup(unlink, path)
        uri = "file:" + urllib.parse.quote(path)
        with contextlib.closing(sqlite.connect(uri, uri=True)) as cx:
            self.assertTrue(os.path.exists(path))
            cx.execute(self._sql)

    def test_factory_database_arg(self):
        def factory(database, *args, **kwargs):
            nonlocal database_arg
            database_arg = database
            return sqlite.Connection(":memory:", *args, **kwargs)

        for database in (TESTFN, os.fsencode(TESTFN),
                         FakePath(TESTFN), FakePath(os.fsencode(TESTFN))):
            database_arg = None
            sqlite.connect(database, factory=factory).close()
            self.assertEqual(database_arg, database)

    def test_database_keyword(self):
        with contextlib.closing(sqlite.connect(database=":memory:")) as cx:
            self.assertEqual(type(cx), sqlite.Connection)


class CursorTests(unittest.TestCase):
    def setUp(self):
        self.cx = sqlite.connect(":memory:")
        self.cu = self.cx.cursor()
        self.cu.execute(
            "create table test(id integer primary key, name text, "
            "income number, unique_test text unique)"
        )
        self.cu.execute("insert into test(name) values (?)", ("foo",))

    def tearDown(self):
        self.cu.close()
        self.cx.close()

    def test_execute_no_args(self):
        self.cu.execute("delete from test")

    def test_execute_illegal_sql(self):
        with self.assertRaises(sqlite.OperationalError):
            self.cu.execute("select asdf")

    def test_execute_multiple_statements(self):
        msg = "You can only execute one statement at a time"
        dataset = (
            "select 1; select 2",
            "select 1; // c++ comments are not allowed",
            "select 1; *not a comment",
            "select 1; -*not a comment",
            "select 1; /* */ a",
            "select 1; /**/a",
            "select 1; -",
            "select 1; /",
            "select 1; -\n- select 2",
            """select 1;
               -- comment
               select 2
            """,
        )
        for query in dataset:
            with self.subTest(query=query):
                with self.assertRaisesRegex(sqlite.ProgrammingError, msg):
                    self.cu.execute(query)

    def test_execute_with_appended_comments(self):
        dataset = (
            "select 1; -- foo bar",
            "select 1; --",
            "select 1; /*",  # Unclosed comments ending in \0 are skipped.
            """
            select 5+4;

            /*
            foo
            */
            """,
        )
        for query in dataset:
            with self.subTest(query=query):
                self.cu.execute(query)

    def test_execute_wrong_sql_arg(self):
        with self.assertRaises(TypeError):
            self.cu.execute(42)

    def test_execute_arg_int(self):
        self.cu.execute("insert into test(id) values (?)", (42,))

    def test_execute_arg_float(self):
        self.cu.execute("insert into test(income) values (?)", (2500.32,))

    def test_execute_arg_string(self):
        self.cu.execute("insert into test(name) values (?)", ("Hugo",))

    def test_execute_arg_string_with_zero_byte(self):
        self.cu.execute("insert into test(name) values (?)", ("Hu\x00go",))

        self.cu.execute("select name from test where id=?", (self.cu.lastrowid,))
        row = self.cu.fetchone()
        self.assertEqual(row[0], "Hu\x00go")

    def test_execute_non_iterable(self):
        with self.assertRaises(sqlite.ProgrammingError) as cm:
            self.cu.execute("insert into test(id) values (?)", 42)
        self.assertEqual(str(cm.exception), 'parameters are of unsupported type')

    def test_execute_wrong_no_of_args1(self):
        # too many parameters
        with self.assertRaises(sqlite.ProgrammingError):
            self.cu.execute("insert into test(id) values (?)", (17, "Egon"))

    def test_execute_wrong_no_of_args2(self):
        # too little parameters
        with self.assertRaises(sqlite.ProgrammingError):
            self.cu.execute("insert into test(id) values (?)")

    def test_execute_wrong_no_of_args3(self):
        # no parameters, parameters are needed
        with self.assertRaises(sqlite.ProgrammingError):
            self.cu.execute("insert into test(id) values (?)")

    def test_execute_param_list(self):
        self.cu.execute("insert into test(name) values ('foo')")
        self.cu.execute("select name from test where name=?", ["foo"])
        row = self.cu.fetchone()
        self.assertEqual(row[0], "foo")

    def test_execute_param_sequence(self):
        class L:
            def __len__(self):
                return 1
            def __getitem__(self, x):
                assert x == 0
                return "foo"

        self.cu.execute("insert into test(name) values ('foo')")
        self.cu.execute("select name from test where name=?", L())
        row = self.cu.fetchone()
        self.assertEqual(row[0], "foo")

    def test_execute_param_sequence_bad_len(self):
        # Issue41662: Error in __len__() was overridden with ProgrammingError.
        class L:
            def __len__(self):
                1/0
            def __getitem__(slf, x):
                raise AssertionError

        self.cu.execute("insert into test(name) values ('foo')")
        with self.assertRaises(ZeroDivisionError):
            self.cu.execute("select name from test where name=?", L())

    def test_execute_named_param_and_sequence(self):
        dataset = (
            ("select :a", (1,)),
            ("select :a, ?, ?", (1, 2, 3)),
            ("select ?, :b, ?", (1, 2, 3)),
            ("select ?, ?, :c", (1, 2, 3)),
            ("select :a, :b, ?", (1, 2, 3)),
        )
        msg = "Binding.*is a named parameter"
        for query, params in dataset:
            with self.subTest(query=query, params=params):
                with self.assertWarnsRegex(DeprecationWarning, msg) as cm:
                    self.cu.execute(query, params)
                self.assertEqual(cm.filename,  __file__)

    def test_execute_indexed_nameless_params(self):
        # See gh-117995: "'?1' is considered a named placeholder"
        for query, params, expected in (
            ("select ?1, ?2", (1, 2), (1, 2)),
            ("select ?2, ?1", (1, 2), (2, 1)),
        ):
            with self.subTest(query=query, params=params):
                with warnings.catch_warnings():
                    warnings.simplefilter("error", DeprecationWarning)
                    cu = self.cu.execute(query, params)
                    actual, = cu.fetchall()
                    self.assertEqual(actual, expected)

    def test_execute_too_many_params(self):
        category = sqlite.SQLITE_LIMIT_VARIABLE_NUMBER
        msg = "too many SQL variables"
        with cx_limit(self.cx, category=category, limit=1):
            self.cu.execute("select * from test where id=?", (1,))
            with self.assertRaisesRegex(sqlite.OperationalError, msg):
                self.cu.execute("select * from test where id!=? and id!=?",
                                (1, 2))

    def test_execute_dict_mapping(self):
        self.cu.execute("insert into test(name) values ('foo')")
        self.cu.execute("select name from test where name=:name", {"name": "foo"})
        row = self.cu.fetchone()
        self.assertEqual(row[0], "foo")

    def test_execute_dict_mapping_mapping(self):
        class D(dict):
            def __missing__(self, key):
                return "foo"

        self.cu.execute("insert into test(name) values ('foo')")
        self.cu.execute("select name from test where name=:name", D())
        row = self.cu.fetchone()
        self.assertEqual(row[0], "foo")

    def test_execute_dict_mapping_too_little_args(self):
        self.cu.execute("insert into test(name) values ('foo')")
        with self.assertRaises(sqlite.ProgrammingError):
            self.cu.execute("select name from test where name=:name and id=:id", {"name": "foo"})

    def test_execute_dict_mapping_no_args(self):
        self.cu.execute("insert into test(name) values ('foo')")
        with self.assertRaises(sqlite.ProgrammingError):
            self.cu.execute("select name from test where name=:name")

    def test_execute_dict_mapping_unnamed(self):
        self.cu.execute("insert into test(name) values ('foo')")
        with self.assertRaises(sqlite.ProgrammingError):
            self.cu.execute("select name from test where name=?", {"name": "foo"})

    def test_close(self):
        self.cu.close()

    def test_rowcount_execute(self):
        self.cu.execute("delete from test")
        self.cu.execute("insert into test(name) values ('foo')")
        self.cu.execute("insert into test(name) values ('foo')")
        self.cu.execute("update test set name='bar'")
        self.assertEqual(self.cu.rowcount, 2)

    def test_rowcount_select(self):
        """
        pysqlite does not know the rowcount of SELECT statements, because we
        don't fetch all rows after executing the select statement. The rowcount
        has thus to be -1.
        """
        self.cu.execute("select 5 union select 6")
        self.assertEqual(self.cu.rowcount, -1)

    def test_rowcount_executemany(self):
        self.cu.execute("delete from test")
        self.cu.executemany("insert into test(name) values (?)", [(1,), (2,), (3,)])
        self.assertEqual(self.cu.rowcount, 3)

    @unittest.skipIf(sqlite.sqlite_version_info < (3, 35, 0),
                     "Requires SQLite 3.35.0 or newer")
    def test_rowcount_update_returning(self):
        # gh-93421: rowcount is updated correctly for UPDATE...RETURNING queries
        self.cu.execute("update test set name='bar' where name='foo' returning 1")
        self.assertEqual(self.cu.fetchone()[0], 1)
        self.assertEqual(self.cu.rowcount, 1)

    def test_rowcount_prefixed_with_comment(self):
        # gh-79579: rowcount is updated even if query is prefixed with comments
        self.cu.execute("""
            -- foo
            insert into test(name) values ('foo'), ('foo')
        """)
        self.assertEqual(self.cu.rowcount, 2)
        self.cu.execute("""
            /* -- messy *r /* /* ** *- *--
            */
            /* one more */ insert into test(name) values ('messy')
        """)
        self.assertEqual(self.cu.rowcount, 1)
        self.cu.execute("/* bar */ update test set name='bar' where name='foo'")
        self.assertEqual(self.cu.rowcount, 3)

    def test_rowcount_vaccuum(self):
        data = ((1,), (2,), (3,))
        self.cu.executemany("insert into test(income) values(?)", data)
        self.assertEqual(self.cu.rowcount, 3)
        self.cx.commit()
        self.cu.execute("vacuum")
        self.assertEqual(self.cu.rowcount, -1)

    def test_total_changes(self):
        self.cu.execute("insert into test(name) values ('foo')")
        self.cu.execute("insert into test(name) values ('foo')")
        self.assertLess(2, self.cx.total_changes, msg='total changes reported wrong value')

    # Checks for executemany:
    # Sequences are required by the DB-API, iterators
    # enhancements in pysqlite.

    def test_execute_many_sequence(self):
        self.cu.executemany("insert into test(income) values (?)", [(x,) for x in range(100, 110)])

    def test_execute_many_iterator(self):
        class MyIter:
            def __init__(self):
                self.value = 5

            def __iter__(self):
                return self

            def __next__(self):
                if self.value == 10:
                    raise StopIteration
                else:
                    self.value += 1
                    return (self.value,)

        self.cu.executemany("insert into test(income) values (?)", MyIter())

    def test_execute_many_generator(self):
        def mygen():
            for i in range(5):
                yield (i,)

        self.cu.executemany("insert into test(income) values (?)", mygen())

    def test_execute_many_wrong_sql_arg(self):
        with self.assertRaises(TypeError):
            self.cu.executemany(42, [(3,)])

    def test_execute_many_select(self):
        with self.assertRaises(sqlite.ProgrammingError):
            self.cu.executemany("select ?", [(3,)])

    def test_execute_many_not_iterable(self):
        with self.assertRaises(TypeError):
            self.cu.executemany("insert into test(income) values (?)", 42)

    def test_fetch_iter(self):
        # Optional DB-API extension.
        self.cu.execute("delete from test")
        self.cu.execute("insert into test(id) values (?)", (5,))
        self.cu.execute("insert into test(id) values (?)", (6,))
        self.cu.execute("select id from test order by id")
        lst = []
        for row in self.cu:
            lst.append(row[0])
        self.assertEqual(lst[0], 5)
        self.assertEqual(lst[1], 6)

    def test_fetchone(self):
        self.cu.execute("select name from test")
        row = self.cu.fetchone()
        self.assertEqual(row[0], "foo")
        row = self.cu.fetchone()
        self.assertEqual(row, None)

    def test_fetchone_no_statement(self):
        cur = self.cx.cursor()
        row = cur.fetchone()
        self.assertEqual(row, None)

    def test_array_size(self):
        # must default to 1
        self.assertEqual(self.cu.arraysize, 1)

        # now set to 2
        self.cu.arraysize = 2

        # now make the query return 2 rows from a table of 3 rows
        self.cu.execute("delete from test")
        self.cu.execute("insert into test(name) values ('A')")
        self.cu.execute("insert into test(name) values ('B')")
        self.cu.execute("insert into test(name) values ('C')")
        self.cu.execute("select name from test")
        res = self.cu.fetchmany()

        self.assertEqual(len(res), 2)

    def test_invalid_array_size(self):
        UINT32_MAX = (1 << 32) - 1
        setter = functools.partial(setattr, self.cu, 'arraysize')

        self.assertRaises(TypeError, setter, 1.0)
        self.assertRaises(ValueError, setter, -3)
        self.assertRaises(OverflowError, setter, UINT32_MAX + 1)

    def test_fetchmany(self):
        # no active SQL statement
        res = self.cu.fetchmany()
        self.assertEqual(res, [])
        res = self.cu.fetchmany(1000)
        self.assertEqual(res, [])

        # test default parameter
        self.cu.execute("select name from test")
        res = self.cu.fetchmany()
        self.assertEqual(len(res), 1)

        # test when the number of requested rows exceeds the actual count
        self.cu.execute("select name from test")
        res = self.cu.fetchmany(100)
        self.assertEqual(len(res), 1)
        res = self.cu.fetchmany(100)
        self.assertEqual(res, [])

        # test when size = 0
        self.cu.execute("select name from test")
        res = self.cu.fetchmany(0)
        self.assertEqual(res, [])
        res = self.cu.fetchmany(100)
        self.assertEqual(len(res), 1)
        res = self.cu.fetchmany(100)
        self.assertEqual(res, [])

    def test_invalid_fetchmany(self):
        UINT32_MAX = (1 << 32) - 1
        fetchmany = self.cu.fetchmany

        self.assertRaises(TypeError, fetchmany, 1.0)
        self.assertRaises(ValueError, fetchmany, -3)
        self.assertRaises(OverflowError, fetchmany, UINT32_MAX + 1)

    def test_fetchmany_kw_arg(self):
        """Checks if fetchmany works with keyword arguments"""
        self.cu.execute("select name from test")
        res = self.cu.fetchmany(size=100)
        self.assertEqual(len(res), 1)

    def test_fetchall(self):
        self.cu.execute("select name from test")
        res = self.cu.fetchall()
        self.assertEqual(len(res), 1)
        res = self.cu.fetchall()
        self.assertEqual(res, [])

    def test_setinputsizes(self):
        self.cu.setinputsizes([3, 4, 5])

    def test_setoutputsize(self):
        self.cu.setoutputsize(5, 0)

    def test_setoutputsize_no_column(self):
        self.cu.setoutputsize(42)

    def test_cursor_connection(self):
        # Optional DB-API extension.
        self.assertEqual(self.cu.connection, self.cx)

    def test_wrong_cursor_callable(self):
        with self.assertRaises(TypeError):
            def f(): pass
            cur = self.cx.cursor(f)

    def test_cursor_wrong_class(self):
        class Foo: pass
        foo = Foo()
        with self.assertRaises(TypeError):
            cur = sqlite.Cursor(foo)

    def test_last_row_id_on_replace(self):
        """
        INSERT OR REPLACE and REPLACE INTO should produce the same behavior.
        """
        sql = '{} INTO test(id, unique_test) VALUES (?, ?)'
        for statement in ('INSERT OR REPLACE', 'REPLACE'):
            with self.subTest(statement=statement):
                self.cu.execute(sql.format(statement), (1, 'foo'))
                self.assertEqual(self.cu.lastrowid, 1)

    def test_last_row_id_on_ignore(self):
        self.cu.execute(
            "insert or ignore into test(unique_test) values (?)",
            ('test',))
        self.assertEqual(self.cu.lastrowid, 2)
        self.cu.execute(
            "insert or ignore into test(unique_test) values (?)",
            ('test',))
        self.assertEqual(self.cu.lastrowid, 2)

    def test_last_row_id_insert_o_r(self):
        results = []
        for statement in ('FAIL', 'ABORT', 'ROLLBACK'):
            sql = 'INSERT OR {} INTO test(unique_test) VALUES (?)'
            with self.subTest(statement='INSERT OR {}'.format(statement)):
                self.cu.execute(sql.format(statement), (statement,))
                results.append((statement, self.cu.lastrowid))
                with self.assertRaises(sqlite.IntegrityError):
                    self.cu.execute(sql.format(statement), (statement,))
                results.append((statement, self.cu.lastrowid))
        expected = [
            ('FAIL', 2), ('FAIL', 2),
            ('ABORT', 3), ('ABORT', 3),
            ('ROLLBACK', 4), ('ROLLBACK', 4),
        ]
        self.assertEqual(results, expected)

    def test_column_count(self):
        # Check that column count is updated correctly for cached statements
        select = "select * from test"
        res = self.cu.execute(select)
        old_count = len(res.description)
        # Add a new column and execute the cached select query again
        self.cu.execute("alter table test add newcol")
        res = self.cu.execute(select)
        new_count = len(res.description)
        self.assertEqual(new_count - old_count, 1)

    def test_same_query_in_multiple_cursors(self):
        cursors = [self.cx.execute("select 1") for _ in range(3)]
        for cu in cursors:
            self.assertEqual(cu.fetchall(), [(1,)])


class BlobTests(unittest.TestCase):
    def setUp(self):
        self.cx = sqlite.connect(":memory:")
        self.cx.execute("create table test(b blob)")
        self.data = b"this blob data string is exactly fifty bytes long!"
        self.cx.execute("insert into test(b) values (?)", (self.data,))
        self.blob = self.cx.blobopen("test", "b", 1)

    def tearDown(self):
        self.blob.close()
        self.cx.close()

    def test_blob_is_a_blob(self):
        self.assertIsInstance(self.blob, sqlite.Blob)

    def test_blob_seek_and_tell(self):
        self.blob.seek(10)
        self.assertEqual(self.blob.tell(), 10)

        self.blob.seek(10, SEEK_SET)
        self.assertEqual(self.blob.tell(), 10)

        self.blob.seek(10, SEEK_CUR)
        self.assertEqual(self.blob.tell(), 20)

        self.blob.seek(-10, SEEK_END)
        self.assertEqual(self.blob.tell(), 40)

    def test_blob_seek_error(self):
        msg_oor = "offset out of blob range"
        msg_orig = "'origin' should be os.SEEK_SET, os.SEEK_CUR, or os.SEEK_END"

        dataset = (
            (ValueError, msg_oor, lambda: self.blob.seek(1000)),
            (ValueError, msg_oor, lambda: self.blob.seek(-10)),
            (ValueError, msg_orig, lambda: self.blob.seek(10, -1)),
            (ValueError, msg_orig, lambda: self.blob.seek(10, 3)),
        )
        for exc, msg, fn in dataset:
            with self.subTest(exc=exc, msg=msg, fn=fn):
                self.assertRaisesRegex(exc, msg, fn)

    def test_blob_seek_overflow_error(self):
        # Force overflow errors
        msg_of = "seek offset results in overflow"
        _testcapi = import_helper.import_module("_testcapi")
        self.blob.seek(1, SEEK_SET)
        with self.assertRaisesRegex(OverflowError, msg_of):
            self.blob.seek(_testcapi.INT_MAX, SEEK_CUR)
        with self.assertRaisesRegex(OverflowError, msg_of):
            self.blob.seek(_testcapi.INT_MAX, SEEK_END)

    def test_blob_read(self):
        buf = self.blob.read()
        self.assertEqual(buf, self.data)

    def test_blob_read_oversized(self):
        buf = self.blob.read(len(self.data) * 2)
        self.assertEqual(buf, self.data)

    def test_blob_read_advance_offset(self):
        n = 10
        buf = self.blob.read(n)
        self.assertEqual(buf, self.data[:n])
        self.assertEqual(self.blob.tell(), n)

    def test_blob_read_at_offset(self):
        self.blob.seek(10)
        self.assertEqual(self.blob.read(10), self.data[10:20])

    def test_blob_read_error_row_changed(self):
        self.cx.execute("update test set b='aaaa' where rowid=1")
        with self.assertRaises(sqlite.OperationalError):
            self.blob.read()

    def test_blob_write(self):
        new_data = b"new data".ljust(50)
        self.blob.write(new_data)
        row = self.cx.execute("select b from test").fetchone()
        self.assertEqual(row[0], new_data)

    def test_blob_write_at_offset(self):
        new_data = b"c" * 25
        self.blob.seek(25)
        self.blob.write(new_data)
        row = self.cx.execute("select b from test").fetchone()
        self.assertEqual(row[0], self.data[:25] + new_data)

    def test_blob_write_advance_offset(self):
        self.blob.write(b"d"*10)
        self.assertEqual(self.blob.tell(), 10)

    def test_blob_write_error_length(self):
        with self.assertRaisesRegex(ValueError, "data longer than blob"):
            self.blob.write(b"a" * 1000)

        self.blob.seek(0, SEEK_SET)
        n = len(self.blob)
        self.blob.write(b"a" * (n-1))
        self.blob.write(b"a")
        with self.assertRaisesRegex(ValueError, "data longer than blob"):
            self.blob.write(b"a")

    def test_blob_write_error_row_changed(self):
        self.cx.execute("update test set b='aaaa' where rowid=1")
        with self.assertRaises(sqlite.OperationalError):
            self.blob.write(b"aaa")

    def test_blob_write_error_readonly(self):
        ro_blob = self.cx.blobopen("test", "b", 1, readonly=True)
        with self.assertRaisesRegex(sqlite.OperationalError, "readonly"):
            ro_blob.write(b"aaa")
        ro_blob.close()

    def test_blob_open_error(self):
        dataset = (
            (("test", "b", 1), {"name": "notexisting"}),
            (("notexisting", "b", 1), {}),
            (("test", "notexisting", 1), {}),
            (("test", "b", 2), {}),
        )
        regex = "no such"
        for args, kwds in dataset:
            with self.subTest(args=args, kwds=kwds):
                with self.assertRaisesRegex(sqlite.OperationalError, regex):
                    self.cx.blobopen(*args, **kwds)

    def test_blob_length(self):
        self.assertEqual(len(self.blob), 50)

    def test_blob_get_item(self):
        self.assertEqual(self.blob[5], ord("b"))
        self.assertEqual(self.blob[6], ord("l"))
        self.assertEqual(self.blob[7], ord("o"))
        self.assertEqual(self.blob[8], ord("b"))
        self.assertEqual(self.blob[-1], ord("!"))

    def test_blob_set_item(self):
        self.blob[0] = ord("b")
        expected = b"b" + self.data[1:]
        actual = self.cx.execute("select b from test").fetchone()[0]
        self.assertEqual(actual, expected)

    def test_blob_set_item_with_offset(self):
        self.blob.seek(0, SEEK_END)
        self.assertEqual(self.blob.read(), b"")  # verify that we're at EOB
        self.blob[0] = ord("T")
        self.blob[-1] = ord(".")
        self.blob.seek(0, SEEK_SET)
        expected = b"This blob data string is exactly fifty bytes long."
        self.assertEqual(self.blob.read(), expected)

    def test_blob_set_slice_buffer_object(self):
        from array import array
        self.blob[0:5] = memoryview(b"12345")
        self.assertEqual(self.blob[0:5], b"12345")

        self.blob[0:5] = bytearray(b"23456")
        self.assertEqual(self.blob[0:5], b"23456")

        self.blob[0:5] = array("b", [1, 2, 3, 4, 5])
        self.assertEqual(self.blob[0:5], b"\x01\x02\x03\x04\x05")

    def test_blob_set_item_negative_index(self):
        self.blob[-1] = 255
        self.assertEqual(self.blob[-1], 255)

    def test_blob_get_slice(self):
        self.assertEqual(self.blob[5:14], b"blob data")

    def test_blob_get_empty_slice(self):
        self.assertEqual(self.blob[5:5], b"")

    def test_blob_get_empty_slice_oob_indices(self):
        self.cx.execute("insert into test(b) values (?)", (b"abc",))
        with self.cx.blobopen("test", "b", 2) as blob:
            self.assertEqual(blob[5:-5], b"")

    def test_blob_get_slice_negative_index(self):
        self.assertEqual(self.blob[5:-5], self.data[5:-5])

    def test_blob_get_slice_with_skip(self):
        self.assertEqual(self.blob[0:10:2], b"ti lb")

    def test_blob_set_slice(self):
        self.blob[0:5] = b"12345"
        expected = b"12345" + self.data[5:]
        actual = self.cx.execute("select b from test").fetchone()[0]
        self.assertEqual(actual, expected)

    def test_blob_set_empty_slice(self):
        self.blob[0:0] = b""
        self.assertEqual(self.blob[:], self.data)

    def test_blob_set_slice_with_skip(self):
        self.blob[0:10:2] = b"12345"
        actual = self.cx.execute("select b from test").fetchone()[0]
        expected = b"1h2s3b4o5 " + self.data[10:]
        self.assertEqual(actual, expected)

    def test_blob_mapping_invalid_index_type(self):
        msg = "indices must be integers"
        with self.assertRaisesRegex(TypeError, msg):
            self.blob[5:5.5]
        with self.assertRaisesRegex(TypeError, msg):
            self.blob[1.5]
        with self.assertRaisesRegex(TypeError, msg):
            self.blob["a"] = b"b"

    def test_blob_get_item_error(self):
        dataset = [len(self.blob), 105, -105]
        for idx in dataset:
            with self.subTest(idx=idx):
                with self.assertRaisesRegex(IndexError, "index out of range"):
                    self.blob[idx]

        # Provoke read error
        self.cx.execute("update test set b='aaaa' where rowid=1")
        with self.assertRaises(sqlite.OperationalError):
            self.blob[0]

    def test_blob_get_item_error_bigint(self):
        _testcapi = import_helper.import_module("_testcapi")
        with self.assertRaisesRegex(IndexError, "cannot fit 'int'"):
            self.blob[_testcapi.ULLONG_MAX]

    def test_blob_set_item_error(self):
        with self.assertRaisesRegex(TypeError, "cannot be interpreted"):
            self.blob[0] = b"multiple"
        with self.assertRaisesRegex(TypeError, "cannot be interpreted"):
            self.blob[0] = b"1"
        with self.assertRaisesRegex(TypeError, "cannot be interpreted"):
            self.blob[0] = bytearray(b"1")
        with self.assertRaisesRegex(TypeError, "doesn't support.*deletion"):
            del self.blob[0]
        with self.assertRaisesRegex(IndexError, "Blob index out of range"):
            self.blob[1000] = 0
        with self.assertRaisesRegex(ValueError, "must be in range"):
            self.blob[0] = -1
        with self.assertRaisesRegex(ValueError, "must be in range"):
            self.blob[0] = 256
        # Overflow errors are overridden with ValueError
        with self.assertRaisesRegex(ValueError, "must be in range"):
            self.blob[0] = 2**65

    def test_blob_set_slice_error(self):
        with self.assertRaisesRegex(IndexError, "wrong size"):
            self.blob[5:10] = b"a"
        with self.assertRaisesRegex(IndexError, "wrong size"):
            self.blob[5:10] = b"a" * 1000
        with self.assertRaisesRegex(TypeError, "doesn't support.*deletion"):
            del self.blob[5:10]
        with self.assertRaisesRegex(ValueError, "step cannot be zero"):
            self.blob[5:10:0] = b"12345"
        with self.assertRaises(BufferError):
            self.blob[5:10] = memoryview(b"abcde")[::2]

    def test_blob_sequence_not_supported(self):
        with self.assertRaisesRegex(TypeError, "unsupported operand"):
            self.blob + self.blob
        with self.assertRaisesRegex(TypeError, "unsupported operand"):
            self.blob * 5
        with self.assertRaisesRegex(TypeError, "is not iterable"):
            b"a" in self.blob

    def test_blob_context_manager(self):
        data = b"a" * 50
        with self.cx.blobopen("test", "b", 1) as blob:
            blob.write(data)
        actual = self.cx.execute("select b from test").fetchone()[0]
        self.assertEqual(actual, data)

        # Check that __exit__ closed the blob
        with self.assertRaisesRegex(sqlite.ProgrammingError, "closed blob"):
            blob.read()

    def test_blob_context_manager_reraise_exceptions(self):
        class DummyException(Exception):
            pass
        with self.assertRaisesRegex(DummyException, "reraised"):
            with self.cx.blobopen("test", "b", 1) as blob:
                raise DummyException("reraised")


    def test_blob_closed(self):
        with memory_database() as cx:
            cx.execute("create table test(b blob)")
            cx.execute("insert into test values (zeroblob(100))")
            blob = cx.blobopen("test", "b", 1)
            blob.close()

            msg = "Cannot operate on a closed blob"
            with self.assertRaisesRegex(sqlite.ProgrammingError, msg):
                blob.read()
            with self.assertRaisesRegex(sqlite.ProgrammingError, msg):
                blob.write(b"")
            with self.assertRaisesRegex(sqlite.ProgrammingError, msg):
                blob.seek(0)
            with self.assertRaisesRegex(sqlite.ProgrammingError, msg):
                blob.tell()
            with self.assertRaisesRegex(sqlite.ProgrammingError, msg):
                blob.__enter__()
            with self.assertRaisesRegex(sqlite.ProgrammingError, msg):
                blob.__exit__(None, None, None)
            with self.assertRaisesRegex(sqlite.ProgrammingError, msg):
                len(blob)
            with self.assertRaisesRegex(sqlite.ProgrammingError, msg):
                blob[0]
            with self.assertRaisesRegex(sqlite.ProgrammingError, msg):
                blob[0:1]
            with self.assertRaisesRegex(sqlite.ProgrammingError, msg):
                blob[0] = b""

    def test_blob_closed_db_read(self):
        with memory_database() as cx:
            cx.execute("create table test(b blob)")
            cx.execute("insert into test(b) values (zeroblob(100))")
            blob = cx.blobopen("test", "b", 1)
            cx.close()
            self.assertRaisesRegex(sqlite.ProgrammingError,
                                   "Cannot operate on a closed database",
                                   blob.read)

    def test_blob_32bit_rowid(self):
        # gh-100370: we should not get an OverflowError for 32-bit rowids
        with memory_database() as cx:
            rowid = 2**32
            cx.execute("create table t(t blob)")
            cx.execute("insert into t(rowid, t) values (?, zeroblob(1))", (rowid,))
            cx.blobopen('t', 't', rowid)


@threading_helper.requires_working_threading()
class ThreadTests(unittest.TestCase):
    def setUp(self):
        self.con = sqlite.connect(":memory:")
        self.cur = self.con.cursor()
        self.cur.execute("create table test(name text, b blob)")
        self.cur.execute("insert into test values('blob', zeroblob(1))")

    def tearDown(self):
        self.cur.close()
        self.con.close()

    @threading_helper.reap_threads
    def _run_test(self, fn, *args, **kwds):
        def run(err):
            try:
                fn(*args, **kwds)
                err.append("did not raise ProgrammingError")
            except sqlite.ProgrammingError:
                pass
            except:
                err.append("raised wrong exception")

        err = []
        t = threading.Thread(target=run, kwargs={"err": err})
        t.start()
        t.join()
        if err:
            self.fail("\n".join(err))

    def test_check_connection_thread(self):
        fns = [
            lambda: self.con.cursor(),
            lambda: self.con.commit(),
            lambda: self.con.rollback(),
            lambda: self.con.close(),
            lambda: self.con.set_trace_callback(None),
            lambda: self.con.set_authorizer(None),
            lambda: self.con.create_collation("foo", None),
            lambda: self.con.setlimit(sqlite.SQLITE_LIMIT_LENGTH, -1),
            lambda: self.con.getlimit(sqlite.SQLITE_LIMIT_LENGTH),
            lambda: self.con.blobopen("test", "b", 1),
        ]
        if hasattr(sqlite.Connection, "serialize"):
            fns.append(lambda: self.con.serialize())
            fns.append(lambda: self.con.deserialize(b""))
        if sqlite.sqlite_version_info >= (3, 25, 0):
            fns.append(lambda: self.con.create_window_function("foo", 0, None))

        for fn in fns:
            with self.subTest(fn=fn):
                self._run_test(fn)

    def test_check_cursor_thread(self):
        fns = [
            lambda: self.cur.execute("insert into test(name) values('a')"),
            lambda: self.cur.close(),
            lambda: self.cur.execute("select name from test"),
            lambda: self.cur.fetchone(),
        ]
        for fn in fns:
            with self.subTest(fn=fn):
                self._run_test(fn)


    @threading_helper.reap_threads
    def test_dont_check_same_thread(self):
        def run(con, err):
            try:
                con.execute("select 1")
            except sqlite.Error:
                err.append("multi-threading not allowed")

        with memory_database(check_same_thread=False) as con:
            err = []
            t = threading.Thread(target=run, kwargs={"con": con, "err": err})
            t.start()
            t.join()
            self.assertEqual(len(err), 0, "\n".join(err))


class ConstructorTests(unittest.TestCase):
    def test_date(self):
        d = sqlite.Date(2004, 10, 28)

    def test_time(self):
        t = sqlite.Time(12, 39, 35)

    def test_timestamp(self):
        ts = sqlite.Timestamp(2004, 10, 28, 12, 39, 35)

    def test_date_from_ticks(self):
        d = sqlite.DateFromTicks(42)

    def test_time_from_ticks(self):
        t = sqlite.TimeFromTicks(42)

    def test_timestamp_from_ticks(self):
        ts = sqlite.TimestampFromTicks(42)

    def test_binary(self):
        b = sqlite.Binary(b"\0'")

class ExtensionTests(unittest.TestCase):
    def setUp(self):
        self.con = sqlite.connect(":memory:")
        self.cur = self.con.cursor()

    def tearDown(self):
        self.cur.close()
        self.con.close()

    def test_script_string_sql(self):
        cur = self.cur
        cur.executescript("""
            -- bla bla
            /* a stupid comment */
            create table a(i);
            insert into a(i) values (5);
            """)
        cur.execute("select i from a")
        res = cur.fetchone()[0]
        self.assertEqual(res, 5)

    def test_script_syntax_error(self):
        with self.assertRaises(sqlite.OperationalError):
            self.cur.executescript("""
                CREATE TABLE test(x);
                asdf;
                CREATE TABLE test2(x)
            """)

    def test_script_error_normal(self):
        with self.assertRaises(sqlite.OperationalError):
            self.cur.executescript("""
                CREATE TABLE test(sadfsadfdsa);
                SELECT foo FROM hurz;
            """)

    def test_cursor_executescript_as_bytes(self):
        with self.assertRaises(TypeError):
            self.cur.executescript(b"""
                CREATE TABLE test(foo);
                INSERT INTO test(foo) VALUES (5);
            """)

    def test_cursor_executescript_with_null_characters(self):
        with self.assertRaises(ValueError):
            self.cur.executescript("""
                CREATE TABLE a(i);\0
                INSERT INTO a(i) VALUES (5);
            """)

    def test_cursor_executescript_with_surrogates(self):
        with self.assertRaises(UnicodeEncodeError):
            self.cur.executescript("""
                CREATE TABLE a(s);
                INSERT INTO a(s) VALUES ('\ud8ff');
            """)

    def test_cursor_executescript_too_large_script(self):
        msg = "query string is too large"
        with memory_database() as cx, cx_limit(cx) as lim:
            cx.executescript("select 'almost too large'".ljust(lim))
            with self.assertRaisesRegex(sqlite.DataError, msg):
                cx.executescript("select 'too large'".ljust(lim+1))

    def test_cursor_executescript_tx_control(self):
        con = self.con
        con.execute("begin")
        self.assertTrue(con.in_transaction)
        con.executescript("select 1")
        self.assertFalse(con.in_transaction)

    def test_connection_execute(self):
        result = self.con.execute("select 5").fetchone()[0]
        self.assertEqual(result, 5, "Basic test of Connection.execute")

    def test_connection_executemany(self):
        con = self.con
        con.execute("create table test(foo)")
        con.executemany("insert into test(foo) values (?)", [(3,), (4,)])
        result = con.execute("select foo from test order by foo").fetchall()
        self.assertEqual(result[0][0], 3, "Basic test of Connection.executemany")
        self.assertEqual(result[1][0], 4, "Basic test of Connection.executemany")

    def test_connection_executescript(self):
        con = self.con
        con.executescript("""
            CREATE TABLE test(foo);
            INSERT INTO test(foo) VALUES (5);
        """)
        result = con.execute("select foo from test").fetchone()[0]
        self.assertEqual(result, 5, "Basic test of Connection.executescript")


class ClosedConTests(unittest.TestCase):
    def check(self, fn, *args, **kwds):
        regex = "Cannot operate on a closed database."
        with self.assertRaisesRegex(sqlite.ProgrammingError, regex):
            fn(*args, **kwds)

    def setUp(self):
        self.con = sqlite.connect(":memory:")
        self.cur = self.con.cursor()
        self.con.close()

    def test_closed_con_cursor(self):
        self.check(self.con.cursor)

    def test_closed_con_commit(self):
        self.check(self.con.commit)

    def test_closed_con_rollback(self):
        self.check(self.con.rollback)

    def test_closed_cur_execute(self):
        self.check(self.cur.execute, "select 4")

    def test_closed_create_function(self):
        def f(x):
            return 17
        self.check(self.con.create_function, "foo", 1, f)

    def test_closed_create_aggregate(self):
        class Agg:
            def __init__(self):
                pass
            def step(self, x):
                pass
            def finalize(self):
                return 17
        self.check(self.con.create_aggregate, "foo", 1, Agg)

    def test_closed_set_authorizer(self):
        def authorizer(*args):
            return sqlite.DENY
        self.check(self.con.set_authorizer, authorizer)

    def test_closed_set_progress_callback(self):
        def progress():
            pass
        self.check(self.con.set_progress_handler, progress, 100)

    def test_closed_call(self):
        self.check(self.con)


class ClosedCurTests(MemoryDatabaseMixin, unittest.TestCase):
    def test_closed(self):
        cur = self.cx.cursor()
        cur.close()

        for method_name in ("execute", "executemany", "executescript", "fetchall", "fetchmany", "fetchone"):
            if method_name in ("execute", "executescript"):
                params = ("select 4 union select 5",)
            elif method_name == "executemany":
                params = ("insert into foo(bar) values (?)", [(3,), (4,)])
            else:
                params = []

            with self.assertRaises(sqlite.ProgrammingError):
                method = getattr(cur, method_name)
                method(*params)


class SqliteOnConflictTests(unittest.TestCase):
    """
    Tests for SQLite's "insert on conflict" feature.

    See https://www.sqlite.org/lang_conflict.html for details.
    """

    def setUp(self):
        self.cx = sqlite.connect(":memory:")
        self.cu = self.cx.cursor()
        self.cu.execute("""
          CREATE TABLE test(
            id INTEGER PRIMARY KEY, name TEXT, unique_name TEXT UNIQUE
          );
        """)

    def tearDown(self):
        self.cu.close()
        self.cx.close()

    def test_on_conflict_rollback_with_explicit_transaction(self):
        self.cx.isolation_level = None  # autocommit mode
        self.cu = self.cx.cursor()
        # Start an explicit transaction.
        self.cu.execute("BEGIN")
        self.cu.execute("INSERT INTO test(name) VALUES ('abort_test')")
        self.cu.execute("INSERT OR ROLLBACK INTO test(unique_name) VALUES ('foo')")
        with self.assertRaises(sqlite.IntegrityError):
            self.cu.execute("INSERT OR ROLLBACK INTO test(unique_name) VALUES ('foo')")
        # Use connection to commit.
        self.cx.commit()
        self.cu.execute("SELECT name, unique_name from test")
        # Transaction should have rolled back and nothing should be in table.
        self.assertEqual(self.cu.fetchall(), [])

    def test_on_conflict_abort_raises_with_explicit_transactions(self):
        # Abort cancels the current sql statement but doesn't change anything
        # about the current transaction.
        self.cx.isolation_level = None  # autocommit mode
        self.cu = self.cx.cursor()
        # Start an explicit transaction.
        self.cu.execute("BEGIN")
        self.cu.execute("INSERT INTO test(name) VALUES ('abort_test')")
        self.cu.execute("INSERT OR ABORT INTO test(unique_name) VALUES ('foo')")
        with self.assertRaises(sqlite.IntegrityError):
            self.cu.execute("INSERT OR ABORT INTO test(unique_name) VALUES ('foo')")
        self.cx.commit()
        self.cu.execute("SELECT name, unique_name FROM test")
        # Expect the first two inserts to work, third to do nothing.
        self.assertEqual(self.cu.fetchall(), [('abort_test', None), (None, 'foo',)])

    def test_on_conflict_rollback_without_transaction(self):
        # Start of implicit transaction
        self.cu.execute("INSERT INTO test(name) VALUES ('abort_test')")
        self.cu.execute("INSERT OR ROLLBACK INTO test(unique_name) VALUES ('foo')")
        with self.assertRaises(sqlite.IntegrityError):
            self.cu.execute("INSERT OR ROLLBACK INTO test(unique_name) VALUES ('foo')")
        self.cu.execute("SELECT name, unique_name FROM test")
        # Implicit transaction is rolled back on error.
        self.assertEqual(self.cu.fetchall(), [])

    def test_on_conflict_abort_raises_without_transactions(self):
        # Abort cancels the current sql statement but doesn't change anything
        # about the current transaction.
        self.cu.execute("INSERT INTO test(name) VALUES ('abort_test')")
        self.cu.execute("INSERT OR ABORT INTO test(unique_name) VALUES ('foo')")
        with self.assertRaises(sqlite.IntegrityError):
            self.cu.execute("INSERT OR ABORT INTO test(unique_name) VALUES ('foo')")
        # Make sure all other values were inserted.
        self.cu.execute("SELECT name, unique_name FROM test")
        self.assertEqual(self.cu.fetchall(), [('abort_test', None), (None, 'foo',)])

    def test_on_conflict_fail(self):
        self.cu.execute("INSERT OR FAIL INTO test(unique_name) VALUES ('foo')")
        with self.assertRaises(sqlite.IntegrityError):
            self.cu.execute("INSERT OR FAIL INTO test(unique_name) VALUES ('foo')")
        self.assertEqual(self.cu.fetchall(), [])

    def test_on_conflict_ignore(self):
        self.cu.execute("INSERT OR IGNORE INTO test(unique_name) VALUES ('foo')")
        # Nothing should happen.
        self.cu.execute("INSERT OR IGNORE INTO test(unique_name) VALUES ('foo')")
        self.cu.execute("SELECT unique_name FROM test")
        self.assertEqual(self.cu.fetchall(), [('foo',)])

    def test_on_conflict_replace(self):
        self.cu.execute("INSERT OR REPLACE INTO test(name, unique_name) VALUES ('Data!', 'foo')")
        # There shouldn't be an IntegrityError exception.
        self.cu.execute("INSERT OR REPLACE INTO test(name, unique_name) VALUES ('Very different data!', 'foo')")
        self.cu.execute("SELECT name, unique_name FROM test")
        self.assertEqual(self.cu.fetchall(), [('Very different data!', 'foo')])


@requires_subprocess()
class MultiprocessTests(unittest.TestCase):
    CONNECTION_TIMEOUT = 0  # Disable the busy timeout.

    def tearDown(self):
        unlink(TESTFN)

    def test_ctx_mgr_rollback_if_commit_failed(self):
        # bpo-27334: ctx manager does not rollback if commit fails
        SCRIPT = f"""if 1:
            import sqlite3
            def wait():
                print("started")
                assert "database is locked" in input()

            cx = sqlite3.connect("{TESTFN}", timeout={self.CONNECTION_TIMEOUT})
            cx.create_function("wait", 0, wait)
            with cx:
                cx.execute("create table t(t)")
            try:
                # execute two transactions; both will try to lock the db
                cx.executescript('''
                    -- start a transaction and wait for parent
                    begin transaction;
                    select * from t;
                    select wait();
                    rollback;

                    -- start a new transaction; would fail if parent holds lock
                    begin transaction;
                    select * from t;
                    rollback;
                ''')
            finally:
                cx.close()
        """

        # spawn child process
        proc = subprocess.Popen(
            [sys.executable, "-c", SCRIPT],
            encoding="utf-8",
            bufsize=0,
            stdin=subprocess.PIPE,
            stdout=subprocess.PIPE,
        )
        self.addCleanup(proc.communicate)

        # wait for child process to start
        self.assertEqual("started", proc.stdout.readline().strip())

        cx = sqlite.connect(TESTFN, timeout=self.CONNECTION_TIMEOUT)
        try:  # context manager should correctly release the db lock
            with cx:
                cx.execute("insert into t values('test')")
        except sqlite.OperationalError as exc:
            proc.stdin.write(str(exc))
        else:
            proc.stdin.write("no error")
        finally:
            cx.close()

        # terminate child process
        self.assertIsNone(proc.returncode)
        try:
            proc.communicate(input="end", timeout=SHORT_TIMEOUT)
        except subprocess.TimeoutExpired:
            proc.kill()
            proc.communicate()
            raise
        self.assertEqual(proc.returncode, 0)


class RowTests(unittest.TestCase):

    def setUp(self):
        self.cx = sqlite.connect(":memory:")
        self.cx.row_factory = sqlite.Row

    def tearDown(self):
        self.cx.close()

    def test_row_keys(self):
        cu = self.cx.execute("SELECT 1 as first, 2 as second")
        row = cu.fetchone()
        self.assertEqual(row.keys(), ["first", "second"])

    def test_row_length(self):
        cu = self.cx.execute("SELECT 1, 2, 3")
        row = cu.fetchone()
        self.assertEqual(len(row), 3)

    def test_row_getitem(self):
        cu = self.cx.execute("SELECT 1 as a, 2 as b")
        row = cu.fetchone()
        self.assertEqual(row[0], 1)
        self.assertEqual(row[1], 2)
        self.assertEqual(row["a"], 1)
        self.assertEqual(row["b"], 2)
        for key in "nokey", 4, 1.2:
            with self.subTest(key=key):
                with self.assertRaises(IndexError):
                    row[key]

    def test_row_equality(self):
        c1 = self.cx.execute("SELECT 1 as a")
        r1 = c1.fetchone()

        c2 = self.cx.execute("SELECT 1 as a")
        r2 = c2.fetchone()

        self.assertIsNot(r1, r2)
        self.assertEqual(r1, r2)

        c3 = self.cx.execute("SELECT 1 as b")
        r3 = c3.fetchone()

        self.assertNotEqual(r1, r3)

    def test_row_no_description(self):
        cu = self.cx.cursor()
        self.assertIsNone(cu.description)

        row = sqlite.Row(cu, ())
        self.assertEqual(row.keys(), [])
        with self.assertRaisesRegex(IndexError, "nokey"):
            row["nokey"]

    def test_row_is_a_sequence(self):
        from collections.abc import Sequence

        cu = self.cx.execute("SELECT 1")
        row = cu.fetchone()

        self.assertTrue(issubclass(sqlite.Row, Sequence))
        self.assertTrue(isinstance(row, Sequence))


if __name__ == "__main__":
    unittest.main()