langchain/libs/community/tests/unit_tests/test_sql_database.py

# flake8: noqa: E501
"""Test SQL database wrapper."""

import pytest
import sqlalchemy as sa
from packaging import version
from sqlalchemy import (
    Column,
    Integer,
    MetaData,
    String,
    Table,
    Text,
    insert,
    select,
)
from sqlalchemy.engine import Engine, Result

from langchain_community.utilities.sql_database import SQLDatabase, truncate_word

is_sqlalchemy_v1 = version.parse(sa.__version__).major == 1

metadata_obj = MetaData()

user = Table(
    "user",
    metadata_obj,
    Column("user_id", Integer, primary_key=True),
    Column("user_name", String(16), nullable=False),
    Column("user_bio", Text, nullable=True),
)

company = Table(
    "company",
    metadata_obj,
    Column("company_id", Integer, primary_key=True),
    Column("company_location", String, nullable=False),
)


@pytest.fixture
def engine() -> Engine:
    return sa.create_engine("sqlite:///:memory:")


@pytest.fixture
def db(engine: Engine) -> SQLDatabase:
    metadata_obj.create_all(engine)
    return SQLDatabase(engine)


@pytest.fixture
def db_lazy_reflection(engine: Engine) -> SQLDatabase:
    metadata_obj.create_all(engine)
    return SQLDatabase(engine, lazy_table_reflection=True)


@pytest.mark.xfail(is_sqlalchemy_v1, reason="SQLAlchemy 1.x issues")
def test_table_info(db: SQLDatabase) -> None:
    """Test that table info is constructed properly."""
    output = db.table_info
    expected_output = """
    CREATE TABLE user (
            user_id INTEGER NOT NULL,
            user_name VARCHAR(16) NOT NULL,
            user_bio TEXT,
            PRIMARY KEY (user_id)
    )
    /*
    3 rows from user table:
    user_id user_name user_bio
    /*


    CREATE TABLE company (
            company_id INTEGER NOT NULL,
            company_location VARCHAR NOT NULL,
            PRIMARY KEY (company_id)
    )
    /*
    3 rows from company table:
    company_id company_location
    */
    """

    assert sorted(" ".join(output.split())) == sorted(" ".join(expected_output.split()))


@pytest.mark.xfail(is_sqlalchemy_v1, reason="SQLAlchemy 1.x issues")
def test_table_info_lazy_reflection(db_lazy_reflection: SQLDatabase) -> None:
    """Test that table info with lazy reflection"""
    assert len(db_lazy_reflection._metadata.sorted_tables) == 0
    output = db_lazy_reflection.get_table_info(["user"])
    assert len(db_lazy_reflection._metadata.sorted_tables) == 1
    expected_output = """
    CREATE TABLE user (
            user_id INTEGER NOT NULL,
            user_name VARCHAR(16) NOT NULL,
            user_bio TEXT,
            PRIMARY KEY (user_id)
    )
    /*
    3 rows from user table:
    user_id user_name user_bio
    /*
    """

    assert sorted(" ".join(output.split())) == sorted(" ".join(expected_output.split()))

    db_lazy_reflection.get_table_info(["company"])
    assert len(db_lazy_reflection._metadata.sorted_tables) == 2
    assert db_lazy_reflection._metadata.sorted_tables[0].name == "company"
    assert db_lazy_reflection._metadata.sorted_tables[1].name == "user"


@pytest.mark.xfail(is_sqlalchemy_v1, reason="SQLAlchemy 1.x issues")
def test_table_info_w_sample_rows(db: SQLDatabase) -> None:
    """Test that table info is constructed properly."""

    # Provision.
    values = [
        {"user_id": 13, "user_name": "Harrison", "user_bio": "bio"},
        {"user_id": 14, "user_name": "Chase", "user_bio": "bio"},
    ]
    stmt = insert(user).values(values)
    db._execute(stmt)

    # Query and verify.
    db = SQLDatabase(db._engine, sample_rows_in_table_info=2)
    output = db.table_info

    expected_output = """
        CREATE TABLE company (
        company_id INTEGER NOT NULL,
        company_location VARCHAR NOT NULL,
        PRIMARY KEY (company_id)
)
        /*
        2 rows from company table:
        company_id company_location
        */

        CREATE TABLE user (
        user_id INTEGER NOT NULL,
        user_name VARCHAR(16) NOT NULL,
        user_bio TEXT,
        PRIMARY KEY (user_id)
        )
        /*
        2 rows from user table:
        user_id user_name user_bio
        13 Harrison bio
        14 Chase bio
        */
        """

    assert sorted(output.split()) == sorted(expected_output.split())


def test_sql_database_run_fetch_all(db: SQLDatabase) -> None:
    """Verify running SQL expressions returning results as strings."""

    # Provision.
    stmt = insert(user).values(
        user_id=13, user_name="Harrison", user_bio="That is my Bio " * 24
    )
    db._execute(stmt)

    # Query and verify.
    command = "select user_id, user_name, user_bio from user where user_id = 13"
    partial_output = db.run(command)
    user_bio = "That is my Bio " * 19 + "That is my..."
    expected_partial_output = f"[(13, 'Harrison', '{user_bio}')]"
    assert partial_output == expected_partial_output

    full_output = db.run(command, include_columns=True)
    expected_full_output = (
        "[{'user_id': 13, 'user_name': 'Harrison', 'user_bio': '%s'}]" % user_bio
    )
    assert full_output == expected_full_output


def test_sql_database_run_fetch_result(db: SQLDatabase) -> None:
    """Verify running SQL expressions returning results as SQLAlchemy `Result` instances."""

    # Provision.
    stmt = insert(user).values(user_id=17, user_name="hwchase")
    db._execute(stmt)

    # Query and verify.
    command = "select user_id, user_name, user_bio from user where user_id = 17"
    result = db.run(command, fetch="cursor", include_columns=True)
    expected = [{"user_id": 17, "user_name": "hwchase", "user_bio": None}]
    assert isinstance(result, Result)
    assert result.mappings().fetchall() == expected


def test_sql_database_run_with_parameters(db: SQLDatabase) -> None:
    """Verify running SQL expressions with query parameters."""

    # Provision.
    stmt = insert(user).values(user_id=17, user_name="hwchase")
    db._execute(stmt)

    # Query and verify.
    command = "select user_id, user_name, user_bio from user where user_id = :user_id"
    full_output = db.run(command, parameters={"user_id": 17}, include_columns=True)
    expected_full_output = "[{'user_id': 17, 'user_name': 'hwchase', 'user_bio': None}]"
    assert full_output == expected_full_output


def test_sql_database_run_sqlalchemy_selectable(db: SQLDatabase) -> None:
    """Verify running SQL expressions using SQLAlchemy selectable."""

    # Provision.
    stmt = insert(user).values(user_id=17, user_name="hwchase")
    db._execute(stmt)

    # Query and verify.
    command = select(user).where(user.c.user_id == 17)
    full_output = db.run(command, include_columns=True)
    expected_full_output = "[{'user_id': 17, 'user_name': 'hwchase', 'user_bio': None}]"
    assert full_output == expected_full_output


def test_sql_database_run_update(db: SQLDatabase) -> None:
    """Test commands which return no rows return an empty string."""

    # Provision.
    stmt = insert(user).values(user_id=13, user_name="Harrison")
    db._execute(stmt)

    # Query and verify.
    command = "update user set user_name='Updated' where user_id = 13"
    output = db.run(command)
    expected_output = ""
    assert output == expected_output


@pytest.mark.skipif(is_sqlalchemy_v1, reason="Requires SQLAlchemy 2 or newer")
def test_sql_database_schema_translate_map() -> None:
    """Verify using statement-specific execution options."""

    engine = sa.create_engine("sqlite:///:memory:")
    db = SQLDatabase(engine)

    # Define query using SQLAlchemy selectable.
    command = select(user).where(user.c.user_id == 17)

    # Define statement-specific execution options.
    execution_options = {"schema_translate_map": {None: "bar"}}

    # Verify the schema translation is applied.
    with pytest.raises(sa.exc.OperationalError) as ex:
        db.run(command, execution_options=execution_options, fetch="cursor")
    assert ex.match("no such table: bar.user")


def test_truncate_word() -> None:
    assert truncate_word("Hello World", length=5) == "He..."
    assert truncate_word("Hello World", length=0) == "Hello World"
    assert truncate_word("Hello World", length=-10) == "Hello World"
    assert truncate_word("Hello World", length=5, suffix="!!!") == "He!!!"
    assert truncate_word("Hello World", length=12, suffix="!!!") == "Hello World"