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# to you under the Apache License, Version 2.0 (the
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#
#   http://www.apache.org/licenses/LICENSE-2.0
#
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# under the License.

import datetime
import string
from pathlib import Path
from typing import Generator

import numpy
import pyarrow
import pyarrow.dataset
import pytest

from adbc_driver_postgresql import ConnectionOptions, StatementOptions, dbapi


@pytest.fixture
def postgres(postgres_uri: str) -> Generator[dbapi.Connection, None, None]:
    with dbapi.connect(postgres_uri) as conn:
        yield conn


def test_conn_current_catalog(postgres: dbapi.Connection) -> None:
    assert postgres.adbc_current_catalog != ""


def test_conn_current_db_schema(postgres: dbapi.Connection) -> None:
    assert postgres.adbc_current_db_schema == "public"


def test_conn_change_db_schema(postgres: dbapi.Connection) -> None:
    assert postgres.adbc_current_db_schema == "public"

    with postgres.cursor() as cur:
        cur.execute("CREATE SCHEMA IF NOT EXISTS dbapischema")

    assert postgres.adbc_current_db_schema == "public"
    postgres.adbc_current_db_schema = "dbapischema"
    assert postgres.adbc_current_db_schema == "dbapischema"


def test_get_objects_schema_filter_outside_search_path(
    postgres: dbapi.Connection,
) -> None:
    schema_name = "dbapi_get_objects_test"
    table_name = "schema_filter_table"

    # Regression test: adbc_get_objects(db_schema_filter=...) should not depend on the
    # connection's current schema/search_path.
    assert postgres.adbc_current_db_schema == "public"

    with postgres.cursor() as cur:
        cur.execute(f'CREATE SCHEMA IF NOT EXISTS "{schema_name}"')
        cur.execute(f'DROP TABLE IF EXISTS "{schema_name}"."{table_name}"')
        cur.execute(f'CREATE TABLE "{schema_name}"."{table_name}" (ints INT)')
    postgres.commit()

    assert postgres.adbc_current_db_schema == "public"

    metadata = (
        postgres.adbc_get_objects(
            depth="tables",
            db_schema_filter=schema_name,
            table_name_filter=table_name,
        )
        .read_all()
        .to_pylist()
    )

    catalog_name = postgres.adbc_current_catalog
    catalog = next(
        (row for row in metadata if row["catalog_name"] == catalog_name), None
    )
    assert catalog is not None

    schemas = catalog["catalog_db_schemas"]
    assert len(schemas) == 1
    assert schemas[0]["db_schema_name"] == schema_name
    tables = schemas[0]["db_schema_tables"]
    assert len(tables) == 1
    assert tables[0]["table_name"] == table_name


def test_conn_get_info(postgres: dbapi.Connection) -> None:
    info = postgres.adbc_get_info()
    assert info["driver_name"] == "ADBC PostgreSQL Driver"
    assert info["driver_adbc_version"] == 1_001_000
    assert info["vendor_name"] == "PostgreSQL"


def test_get_statistics(postgres: dbapi.Connection) -> None:
    with postgres.cursor() as cur:
        cur.execute("DROP TABLE IF EXISTS test_statistics")
        cur.execute("CREATE TABLE test_statistics (id INT PRIMARY KEY, value TEXT)")
        cur.execute("INSERT INTO test_statistics VALUES (1, 'a'), (2, 'b'), (3, 'c')")
        cur.execute("ANALYZE test_statistics")
    postgres.commit()

    # PostgreSQL requires db_schema to be specified and only supports approximate stats
    reader = postgres.adbc_get_statistics(
        db_schema_filter="public", table_name_filter="test_statistics", approximate=True
    )
    assert reader is not None
    table = reader.read_all()

    # Verify schema is correct
    assert "catalog_name" in table.schema.names
    assert "catalog_db_schemas" in table.schema.names

    # Verify we got actual statistics for our table
    result_list = table.to_pylist()
    found_test_table = False
    for catalog in result_list:
        for schema in catalog["catalog_db_schemas"]:
            assert schema["db_schema_name"] == "public"
            found_test_table = found_test_table or any(
                stat["table_name"] == "test_statistics"
                for stat in schema["db_schema_statistics"]
            )

    assert found_test_table, "Expected statistics for 'test_statistics'"


def test_get_statistic_names(postgres: dbapi.Connection) -> None:
    reader = postgres.adbc_get_statistic_names()
    assert reader is not None
    table = reader.read_all()

    # Verify schema
    assert "statistic_name" in table.schema.names
    assert "statistic_key" in table.schema.names


def test_query_batch_size(postgres: dbapi.Connection):
    with postgres.cursor() as cur:
        cur.execute("DROP TABLE IF EXISTS test_batch_size")
        cur.execute("CREATE TABLE test_batch_size (ints INT)")
        cur.execute(
            """
            INSERT INTO test_batch_size (ints)
            SELECT generated :: INT
            FROM GENERATE_SERIES(1, 65536) temp(generated)
        """
        )

        cur.execute("SELECT * FROM test_batch_size")
        table = cur.fetch_arrow_table()
        assert len(table.to_batches()) == 1

        cur.adbc_statement.set_options(
            **{StatementOptions.BATCH_SIZE_HINT_BYTES.value: "1"}
        )
        assert (
            cur.adbc_statement.get_option_int(
                StatementOptions.BATCH_SIZE_HINT_BYTES.value
            )
            == 1
        )
        cur.execute("SELECT * FROM test_batch_size")
        table = cur.fetch_arrow_table()
        assert len(table.to_batches()) == 65536

        cur.adbc_statement.set_options(
            **{StatementOptions.BATCH_SIZE_HINT_BYTES.value: "4096"}
        )
        assert (
            cur.adbc_statement.get_option_int(
                StatementOptions.BATCH_SIZE_HINT_BYTES.value
            )
            == 4096
        )
        cur.execute("SELECT * FROM test_batch_size")
        table = cur.fetch_arrow_table()
        assert 64 <= len(table.to_batches()) <= 256


def test_query_cancel(postgres: dbapi.Connection) -> None:
    with postgres.cursor() as cur:
        cur.execute("DROP TABLE IF EXISTS test_batch_size")
        cur.execute("CREATE TABLE test_batch_size (ints INT)")
        cur.execute(
            """
            INSERT INTO test_batch_size (ints)
            SELECT generated :: INT
            FROM GENERATE_SERIES(1, 1048576) temp(generated)
        """
        )
        postgres.commit()

    # Ensure different ways of reading all raise the desired error
    with postgres.cursor() as cur:
        cur.execute("SELECT * FROM test_batch_size")
        cur.adbc_cancel()
        with pytest.raises(postgres.OperationalError, match="canceling statement"):
            cur.fetchone()

    postgres.rollback()

    with postgres.cursor() as cur:
        cur.execute("SELECT * FROM test_batch_size")
        cur.adbc_cancel()
        with pytest.raises(postgres.OperationalError, match="canceling statement"):
            cur.fetch_arrow_table()

    postgres.rollback()

    with postgres.cursor() as cur:
        cur.execute("SELECT * FROM test_batch_size")
        cur.adbc_cancel()
        with pytest.raises(postgres.OperationalError, match="canceling statement"):
            cur.fetch_df()


def test_query_execute_schema(postgres: dbapi.Connection) -> None:
    with postgres.cursor() as cur:
        schema = cur.adbc_execute_schema("SELECT 1 AS foo")
        assert schema == pyarrow.schema([("foo", "int32")])


def test_query_invalid(postgres: dbapi.Connection) -> None:
    with postgres.cursor() as cur:
        with pytest.raises(
            postgres.ProgrammingError, match="Failed to prepare query"
        ) as excinfo:
            cur.execute("SELECT * FROM tabledoesnotexist")

        assert excinfo.value.sqlstate == "42P01"
        assert len(excinfo.value.details) > 0


def test_query_trivial(postgres: dbapi.Connection):
    with postgres.cursor() as cur:
        cur.execute("SELECT 1")
        assert cur.fetchone() == (1,)


def test_stmt_ingest(postgres: dbapi.Connection) -> None:
    table = pyarrow.table(
        [
            [1, 2, 3],
            ["a", None, "b"],
        ],
        names=["ints", "strs"],
    )
    double_table = pyarrow.table(
        [
            [1, 1, 2, 2, 3, 3],
            ["a", "a", None, None, "b", "b"],
        ],
        names=["ints", "strs"],
    )

    with postgres.cursor() as cur:
        cur.execute("DROP TABLE IF EXISTS test_ingest")

        with pytest.raises(
            postgres.ProgrammingError, match='"public.test_ingest" does not exist'
        ):
            cur.adbc_ingest("test_ingest", table, mode="append")
        postgres.rollback()

        cur.adbc_ingest("test_ingest", table, mode="replace")
        cur.execute("SELECT * FROM test_ingest ORDER BY ints")
        assert cur.fetch_arrow_table() == table
        postgres.commit()

        with pytest.raises(
            postgres.ProgrammingError, match='"test_ingest" already exists'
        ):
            cur.adbc_ingest("test_ingest", table, mode="create")
        postgres.rollback()

        cur.adbc_ingest("test_ingest", table, mode="create_append")
        cur.execute("SELECT * FROM test_ingest ORDER BY ints")
        assert cur.fetch_arrow_table() == double_table

        cur.adbc_ingest("test_ingest", table, mode="replace")
        cur.execute("SELECT * FROM test_ingest ORDER BY ints")
        assert cur.fetch_arrow_table() == table

        cur.execute("DROP TABLE IF EXISTS test_ingest")

        cur.adbc_ingest("test_ingest", table, mode="create_append")
        cur.execute("SELECT * FROM test_ingest ORDER BY ints")
        assert cur.fetch_arrow_table() == table

        cur.execute("DROP TABLE IF EXISTS test_ingest")

        cur.adbc_ingest("test_ingest", table, mode="create")
        cur.execute("SELECT * FROM test_ingest ORDER BY ints")
        assert cur.fetch_arrow_table() == table


def test_stmt_ingest_dataset(postgres: dbapi.Connection, tmp_path: Path) -> None:
    # Regression test for https://github.com/apache/arrow-adbc/issues/1310
    table = pyarrow.table(
        [
            [1, 1, 2, 2, 3, 3],
            ["a", "a", None, None, "b", "b"],
        ],
        schema=pyarrow.schema([("ints", "int32"), ("strs", "string")]),
    )
    pyarrow.dataset.write_dataset(
        table, tmp_path, format="parquet", partitioning=["ints"]
    )
    ds = pyarrow.dataset.dataset(tmp_path, format="parquet", partitioning=["ints"])

    with postgres.cursor() as cur:
        for item in (
            lambda: ds,
            lambda: ds.scanner(),
            lambda: ds.scanner().to_reader(),
            lambda: ds.scanner().to_table(),
        ):
            cur.execute("DROP TABLE IF EXISTS test_ingest")

            cur.adbc_ingest(
                "test_ingest",
                item(),
                mode="create_append",
            )
            cur.execute("SELECT ints, strs FROM test_ingest ORDER BY ints")
            assert cur.fetch_arrow_table() == table


def test_stmt_ingest_multi(postgres: dbapi.Connection) -> None:
    # Regression test for https://github.com/apache/arrow-adbc/issues/1310
    table = pyarrow.table(
        [
            [1, 1, 2, 2, 3, 3],
            ["a", "a", None, None, "b", "b"],
        ],
        names=["ints", "strs"],
    )

    with postgres.cursor() as cur:
        cur.execute("DROP TABLE IF EXISTS test_ingest")

        cur.adbc_ingest(
            "test_ingest",
            table.to_batches(max_chunksize=2),
            mode="create_append",
        )
        cur.execute("SELECT * FROM test_ingest ORDER BY ints")
        assert cur.fetch_arrow_table() == table


def test_stmt_ingest_timestamptz(postgres: dbapi.Connection) -> None:
    # Regression test for https://github.com/apache/arrow-adbc/issues/2901
    table = pyarrow.table(
        [
            [1],
            [datetime.datetime(2023, 1, 2, 3, 4, 5, tzinfo=datetime.timezone.utc)],
        ],
        names=["ints", "tstz"],
    )

    with postgres.cursor() as cur:
        cur.execute("DROP TABLE IF EXISTS test_ingest")
        # Make sure we aren't in UTC time zone
        cur.execute("SET TIME ZONE 'Asia/Tokyo'")
        postgres.commit()

        cur.execute("SELECT current_setting('TIMEZONE')")
        assert cur.fetchone() == ("Asia/Tokyo",)

        cur.adbc_ingest(
            "test_ingest",
            table,
            mode="create",
        )
        postgres.commit()

        cur.execute("SELECT * FROM test_ingest ORDER BY ints")
        assert cur.fetch_arrow_table() == table


def test_ddl(postgres: dbapi.Connection):
    with postgres.cursor() as cur:
        cur.execute("DROP TABLE IF EXISTS test_ddl")
        assert cur.fetchone() is None

        cur.execute("CREATE TABLE test_ddl (ints INT)")
        assert cur.fetchone() is None

        cur.execute("INSERT INTO test_ddl VALUES (1) RETURNING ints")
        assert cur.fetchone() == (1,)

        cur.execute("SELECT * FROM test_ddl")
        assert cur.fetchone() == (1,)


def test_crash(postgres: dbapi.Connection) -> None:
    with postgres.cursor() as cur:
        cur.execute("SELECT 1")
        assert cur.fetchone() == (1,)


def test_reuse(postgres: dbapi.Connection) -> None:
    with postgres.cursor() as cur:
        cur.execute("DROP TABLE IF EXISTS test_batch_size")
        cur.execute("CREATE TABLE test_batch_size (ints INT)")
        cur.execute(
            """
            INSERT INTO test_batch_size (ints)
            SELECT generated :: INT
            FROM GENERATE_SERIES(1, 65536) temp(generated)
        """
        )

        cur.execute("SELECT * FROM test_batch_size ORDER BY ints ASC")
        assert cur.fetchone() == (1,)

        cur.execute("SELECT 1")
        assert cur.fetchone() == (1,)

        cur.execute("SELECT 2")
        assert cur.fetchone() == (2,)


def test_ingest(postgres: dbapi.Connection) -> None:
    table = pyarrow.Table.from_pydict({"numbers": [1, 2], "letters": ["a", "b"]})

    with postgres.cursor() as cur:
        cur.adbc_ingest("foo", table, mode="replace", db_schema_name="public")

        cur.execute("SELECT * FROM public.foo")
        assert cur.fetch_arrow_table() == table

        with pytest.raises(dbapi.NotSupportedError):
            cur.adbc_ingest("foo", table, catalog_name="main")


def test_ingest_schema(postgres: dbapi.Connection) -> None:
    table = pyarrow.Table.from_pydict({"numbers": [1, 2], "letters": ["a", "b"]})

    with postgres.cursor() as cur:
        cur.execute("CREATE SCHEMA IF NOT EXISTS testschema")
        cur.execute("DROP TABLE IF EXISTS testschema.foo")

        postgres.commit()

        cur.adbc_ingest("foo", table, mode="create", db_schema_name="testschema")

        cur.execute("SELECT * FROM testschema.foo ORDER BY numbers")
        assert cur.fetch_arrow_table() == table


def test_ingest_temporary(postgres: dbapi.Connection) -> None:
    table = pyarrow.Table.from_pydict(
        {
            "numbers": [1, 2],
            "letters": ["a", "b"],
        }
    )
    temp = pyarrow.Table.from_pydict(
        {
            "ints": [3, 4],
            "strs": ["c", "d"],
        }
    )

    table2 = pyarrow.Table.from_pydict(
        {
            "numbers": [1, 2, 1, 2],
            "letters": ["a", "b", "a", "b"],
        }
    )
    temp2 = pyarrow.Table.from_pydict(
        {
            "ints": [3, 4, 3, 4],
            "strs": ["c", "d", "c", "d"],
        }
    )

    with postgres.cursor() as cur:
        cur.execute("DROP TABLE IF EXISTS public.temporary")
        cur.execute("DROP TABLE IF EXISTS pg_temp.temporary")

        cur.adbc_ingest("temporary", table, mode="create")
        cur.adbc_ingest("temporary", temp, mode="create", temporary=True)

        cur.execute("SELECT * FROM public.temporary")
        assert cur.fetch_arrow_table() == table
        cur.execute("SELECT * FROM pg_temp.temporary")
        assert cur.fetch_arrow_table() == temp
        cur.execute("SELECT * FROM temporary")
        assert cur.fetch_arrow_table() == temp

        cur.adbc_ingest("temporary", table, mode="append")
        cur.adbc_ingest("temporary", temp, mode="append", temporary=True)

        cur.execute("SELECT * FROM public.temporary")
        assert cur.fetch_arrow_table() == table2
        cur.execute("SELECT * FROM pg_temp.temporary")
        assert cur.fetch_arrow_table() == temp2
        cur.execute("SELECT * FROM temporary")
        assert cur.fetch_arrow_table() == temp2

        cur.adbc_ingest("temporary", table, mode="replace")
        cur.adbc_ingest("temporary", temp, mode="replace", temporary=True)

        cur.execute("SELECT * FROM public.temporary")
        assert cur.fetch_arrow_table() == table
        cur.execute("SELECT * FROM pg_temp.temporary")
        assert cur.fetch_arrow_table() == temp
        cur.execute("SELECT * FROM temporary")
        assert cur.fetch_arrow_table() == temp

        cur.adbc_ingest("temporary", table, mode="create_append")
        cur.adbc_ingest("temporary", temp, mode="create_append", temporary=True)

        cur.execute("SELECT * FROM public.temporary")
        assert cur.fetch_arrow_table() == table2
        cur.execute("SELECT * FROM pg_temp.temporary")
        assert cur.fetch_arrow_table() == temp2
        cur.execute("SELECT * FROM temporary")
        assert cur.fetch_arrow_table() == temp2


def test_ingest_large(postgres: dbapi.Connection) -> None:
    """Regression test for #1921."""
    # More than 1 GiB of data in one batch
    arr = pyarrow.array(numpy.random.randint(-100, 100, size=4_000_000))
    batch = pyarrow.RecordBatch.from_pydict(
        {char: arr for char in string.ascii_lowercase}
    )
    table = pyarrow.Table.from_batches([batch] * 4)
    with postgres.cursor() as cur:
        cur.adbc_ingest("test_ingest_large", table, mode="replace")


def test_timestamp_txn(postgres: dbapi.Connection) -> None:
    """Regression test for #2410."""
    ts = datetime.datetime.now()
    ts_with_tz = datetime.datetime.now(tz=datetime.timezone.utc)

    with postgres.cursor() as cur:
        cur.execute("DROP TABLE IF EXISTS ts_txn")
        cur.execute("CREATE TABLE ts_txn (ts TIMESTAMP WITH TIME ZONE);")
    postgres.commit()

    with postgres.cursor() as cur:
        cur.execute("INSERT INTO ts_txn VALUES ($1)", parameters=[ts])
        cur.execute("SELECT pg_current_xact_id_if_assigned()")
        assert cur.fetchone() != (None,)
    postgres.commit()

    with postgres.cursor() as cur:
        cur.execute("INSERT INTO ts_txn VALUES ($1)", parameters=[ts_with_tz])
        cur.execute("SELECT pg_current_xact_id_if_assigned()")
        assert cur.fetchone() != (None,)
    postgres.commit()


def test_txn_status(postgres: dbapi.Connection) -> None:
    def status() -> str:
        return postgres.adbc_connection.get_option(
            ConnectionOptions.TRANSACTION_STATUS.value
        )

    assert status() == "intrans"
    postgres.rollback()
    assert status() == "intrans"

    with postgres.cursor() as cur:
        cur.execute("SELECT 1")
        assert status() == "active"
        postgres.commit()
        assert status() == "intrans"
        cur.execute("SELECT 1")
        assert status() == "active"
        postgres.rollback()
        assert status() == "intrans"


def test_connect_conn_kwargs_db_schema(postgres_uri: str, postgres: dbapi.Connection):
    """Verify current DB schema can be set via conn_kwargs."""
    schema_key = "adbc.connection.db_schema"
    schema_name = "dbapi_test_schema_via_option"

    with postgres.cursor() as cur:
        cur.execute(f"DROP SCHEMA IF EXISTS {schema_name} CASCADE")
        cur.execute(f"CREATE SCHEMA {schema_name}")
    postgres.commit()
    with dbapi.connect(postgres_uri, conn_kwargs={schema_key: schema_name}) as conn:
        option_value = conn.adbc_connection.get_option(schema_key)
        assert option_value == schema_name


def test_server_terminates_connection(postgres_uri: str) -> None:
    """Test that driver handles server terminating the connection gracefully.

    Reproduces: https://github.com/apache/arrow-adbc/issues/3878
    When the server terminates a connection, the driver should return an error
    instead of crashing with a segfault.
    """
    with dbapi.connect(postgres_uri) as conn1:
        with dbapi.connect(postgres_uri) as conn2:
            # Get the backend PID of conn2
            with conn2.cursor() as cur:
                cur.execute("SELECT pg_backend_pid()")
                row = cur.fetchone()
                assert row is not None
                backend_pid = row[0]
            conn2.commit()

            # simulate a server side termination of a connection2
            with conn1.cursor() as cur:
                cur.execute(f"SELECT pg_terminate_backend({backend_pid})")
            conn1.commit()

            # Try to execute a query on the terminated connection
            # This should raise an exception, NOT crash with a segfault
            with pytest.raises(Exception):
                with conn2.cursor() as cur:
                    cur.execute("SELECT 1")


# Tests for issue #3549: Cannot use null values as bound parameters
def test_bind_null_insert(postgres: dbapi.Connection) -> None:
    """Test INSERT with None parameter (issue #3549)."""
    with postgres.cursor() as cur:
        cur.execute("DROP TABLE IF EXISTS test_null_binding")
        cur.execute("CREATE TABLE test_null_binding(a TEXT, b INT)")
        # This should not raise an error about mapping Arrow type 'na' to Postgres type
        cur.execute("INSERT INTO test_null_binding VALUES ($1, $2)", ("hello", None))
    postgres.commit()

    with postgres.cursor() as cur:
        cur.execute("SELECT a, b FROM test_null_binding")
        result = cur.fetchone()
        assert result is not None
        assert result[0] == "hello"
        assert result[1] is None


def test_bind_null_update(postgres: dbapi.Connection) -> None:
    """Test UPDATE with None parameter (issue #3549)."""
    with postgres.cursor() as cur:
        cur.execute("DROP TABLE IF EXISTS test_null_binding")
        cur.execute("CREATE TABLE test_null_binding(a TEXT, b INT)")
        cur.execute("INSERT INTO test_null_binding VALUES ('hello', 42)")
    postgres.commit()

    with postgres.cursor() as cur:
        # This should not raise an error
        cur.execute("UPDATE test_null_binding SET b=$2 WHERE a=$1", ("hello", None))
    postgres.commit()

    with postgres.cursor() as cur:
        cur.execute("SELECT a, b FROM test_null_binding WHERE a='hello'")
        result = cur.fetchone()
        assert result is not None
        assert result[0] == "hello"
        assert result[1] is None


def test_executemany_all_nulls(postgres: dbapi.Connection) -> None:
    """Test executemany with all None values (issue #3549)."""
    with postgres.cursor() as cur:
        cur.execute("DROP TABLE IF EXISTS test_null_binding")
        cur.execute("CREATE TABLE test_null_binding(a TEXT, b INT)")
    postgres.commit()

    with postgres.cursor() as cur:
        # This is the critical test case from the issue
        cur.executemany(
            "INSERT INTO test_null_binding VALUES ($1, $2)",
            [("hello", None), ("world", None)],
        )
    postgres.commit()

    with postgres.cursor() as cur:
        cur.execute("SELECT a, b FROM test_null_binding ORDER BY a")
        rows = cur.fetchall()
        assert len(rows) == 2
        assert rows[0] == ("hello", None)
        assert rows[1] == ("world", None)


def test_bind_multiple_null_parameters(postgres: dbapi.Connection) -> None:
    """Test binding multiple None parameters in a single statement (issue #3549)."""
    with postgres.cursor() as cur:
        cur.execute("DROP TABLE IF EXISTS test_null_binding")
        cur.execute("CREATE TABLE test_null_binding(a INT, b TEXT, c FLOAT)")
    postgres.commit()

    with postgres.cursor() as cur:
        # All parameters are None
        cur.execute(
            "INSERT INTO test_null_binding VALUES ($1, $2, $3)", (None, None, None)
        )
    postgres.commit()

    with postgres.cursor() as cur:
        cur.execute("SELECT * FROM test_null_binding")
        result = cur.fetchone()
        assert result is not None
        assert result[0] is None
        assert result[1] is None
        assert result[2] is None


def test_bind_null_unknown_inference(postgres: dbapi.Connection) -> None:
    """Test binding None where PostgreSQL can't infer a concrete parameter type."""
    with postgres.cursor() as cur:
        cur.execute("SELECT $1", (None,))
        result = cur.fetchone()
        assert result is not None
        assert result[0] is None