[Feature] Add support to use any sql database as the metadata storage for embedchain apps (#1273)

embedchain/core/db/database.py

@@ -0,0 +1,83 @@
+import os
+
+from alembic import command
+from alembic.config import Config
+from sqlalchemy import create_engine
+from sqlalchemy.engine.base import Engine
+from sqlalchemy.orm import Session as SQLAlchemySession
+from sqlalchemy.orm import scoped_session, sessionmaker
+
+from .models import Base
+
+
+class DatabaseManager:
+    def __init__(self, database_uri: str = "sqlite:///embedchain.db", echo: bool = False):
+        self.database_uri = database_uri
+        self.echo = echo
+        self.engine: Engine = None
+        self._session_factory = None
+
+    def setup_engine(self) -> None:
+        """Initializes the database engine and session factory."""
+        self.engine = create_engine(self.database_uri, echo=self.echo, connect_args={"check_same_thread": False})
+        self._session_factory = scoped_session(sessionmaker(bind=self.engine))
+        Base.metadata.bind = self.engine
+
+    def init_db(self) -> None:
+        """Creates all tables defined in the Base metadata."""
+        if not self.engine:
+            raise RuntimeError("Database engine is not initialized. Call setup_engine() first.")
+        Base.metadata.create_all(self.engine)
+
+    def get_session(self) -> SQLAlchemySession:
+        """Provides a session for database operations."""
+        if not self._session_factory:
+            raise RuntimeError("Session factory is not initialized. Call setup_engine() first.")
+        return self._session_factory()
+
+    def close_session(self) -> None:
+        """Closes the current session."""
+        if self._session_factory:
+            self._session_factory.remove()
+
+    def execute_transaction(self, transaction_block):
+        """Executes a block of code within a database transaction."""
+        session = self.get_session()
+        try:
+            transaction_block(session)
+            session.commit()
+        except Exception as e:
+            session.rollback()
+            raise e
+        finally:
+            self.close_session()
+
+
+# Singleton pattern to use throughout the application
+database_manager = DatabaseManager()
+
+
+# Convenience functions for backward compatibility and ease of use
+def setup_engine(database_uri: str = "sqlite:///embedchain.db", echo: bool = False) -> None:
+    database_manager.database_uri = database_uri
+    database_manager.echo = echo
+    database_manager.setup_engine()
+
+
+def alembic_upgrade() -> None:
+    """Upgrades the database to the latest version."""
+    alembic_config_path = os.path.join(os.path.dirname(__file__), "..", "..", "alembic.ini")
+    alembic_cfg = Config(alembic_config_path)
+    command.upgrade(alembic_cfg, "head")
+
+
+def init_db() -> None:
+    alembic_upgrade()
+
+
+def get_session() -> SQLAlchemySession:
+    return database_manager.get_session()
+
+
+def execute_transaction(transaction_block):
+    database_manager.execute_transaction(transaction_block)

embedchain/core/db/models.py

@@ -0,0 +1,31 @@
+import uuid
+
+from sqlalchemy import TIMESTAMP, Column, Integer, String, Text, func
+from sqlalchemy.orm import declarative_base
+
+Base = declarative_base()
+metadata = Base.metadata
+
+
+class DataSource(Base):
+    __tablename__ = "ec_data_sources"
+
+    id = Column(String, primary_key=True, default=lambda: str(uuid.uuid4()))
+    app_id = Column(Text, index=True)
+    hash = Column(Text, index=True)
+    type = Column(Text, index=True)
+    value = Column(Text)
+    meta_data = Column(Text, name="metadata")
+    is_uploaded = Column(Integer, default=0)
+
+
+class ChatHistory(Base):
+    __tablename__ = "ec_chat_history"
+
+    app_id = Column(String, primary_key=True)
+    id = Column(String, primary_key=True)
+    session_id = Column(String, primary_key=True, index=True)
+    question = Column(Text)
+    answer = Column(Text)
+    meta_data = Column(Text, name="metadata")
+    created_at = Column(TIMESTAMP, default=func.current_timestamp(), index=True)