**Description:**
`_ListSQLDatabaseToolInput` raise error if model returns `{}`.
For example, gpt-4-turbo returns `{}` with SQL Agent initialized by
`create_sql_agent`.
So, I set default value `""` for `_ListSQLDatabaseToolInput` tool_input.
This is actually a gpt-4-turbo issue, not a LangChain issue, but I
thought it would be helpful to set a default value `""`.
This problem is discussed in detail in the following Issue.
**Issue:** https://github.com/langchain-ai/langchain/issues/20405
**Dependencies:** none
Sorry, I did not add or change the test code, as tests for this
components was not exist .
However, I have tested the following code based on the [SQL Agent
Document](https://python.langchain.com/docs/use_cases/sql/agents/), to
make sure it works.
```
from langchain_community.agent_toolkits.sql.base import create_sql_agent
from langchain_community.utilities.sql_database import SQLDatabase
from langchain_openai import ChatOpenAI
db = SQLDatabase.from_uri("sqlite:///Chinook.db")
llm = ChatOpenAI(model="gpt-4-turbo", temperature=0)
agent_executor = create_sql_agent(llm, db=db, agent_type="openai-tools", verbose=True)
result = agent_executor.invoke("List the total sales per country. Which country's customers spent the most?")
print(result["output"])
```
- **Description:** This modification adds pydantic input definition for
sql_database tools. This helps for function calling capability in
LangGraph. Since actions nodes will usually check for the args_schema
attribute on tools, This update should make these tools compatible with
it (only implemented on the InfoSQLDatabaseTool)
- **Issue:** N/A
- **Dependencies:** N/A
- **Twitter handle:** juanfe8881
**Description:**
Change type hint on `QuerySQLDataBaseTool` to be compatible with
SQLAlchemy v1.4.x.
**Issue:**
Users locked to `SQLAlchemy < 2.x` are unable to import
`QuerySQLDataBaseTool`.
closes https://github.com/langchain-ai/langchain/issues/17819
**Dependencies:**
None
