app/utils/database_connection.py

from langchain_community.utilities import SQLDatabase
from langchain_community.agent_toolkits import SQLDatabaseToolkit


class DatabaseConnection: 
    def __init__(self,connection_string: str):
        self.db = None
        self.setup_database_connection(connection_string)

    def setup_database_connection(self, connection_string: str):
        """Set up database connection and initialize tools"""
        try:
            # Initialize database connection
            self.db = SQLDatabase.from_uri(connection_string)
            print("Database connection successful!")

            return self.db

        except ImportError as e:
            print(f"Database driver import error: {str(e)}")
            raise ValueError(f"Missing database driver or invalid database type: {str(e)}")
        except ValueError as e:
            print(f"Invalid connection string or configuration: {str(e)}")
            raise
        except Exception as e:
            print(f"Unexpected error during database connection: {str(e)}")
            raise ValueError(f"Failed to establish database connection: {str(e)}")