Initial commit: 浼佷笟寰俊 AI 鏈哄櫒浜哄姪鐞?MVP

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/alembic/versions/004_chat_sessions_and_messages.py

@@ -0,0 +1,59 @@
+"""Create chat_sessions and messages tables.
+
+Revision ID: 004
+Revises: 003
+Create Date: 2025-02-05 15:30:00.000000
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision: str = "004"
+down_revision: Union[str, None] = "003"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    from sqlalchemy import inspect
+    
+    conn = op.get_bind()
+    inspector = inspect(conn)
+    tables = inspector.get_table_names()
+    
+    if "chat_sessions" not in tables:
+        op.create_table(
+            "chat_sessions",
+            sa.Column("id", sa.Integer(), nullable=False, autoincrement=True),
+            sa.Column("external_user_id", sa.String(128), nullable=False),
+            sa.Column("external_name", sa.String(128), nullable=True),
+            sa.Column("status", sa.String(32), nullable=False, server_default="open"),
+            sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+            sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+            sa.PrimaryKeyConstraint("id"),
+        )
+        op.create_index(op.f("ix_chat_sessions_external_user_id"), "chat_sessions", ["external_user_id"], unique=False)
+    
+    if "messages" not in tables:
+        op.create_table(
+            "messages",
+            sa.Column("id", sa.Integer(), nullable=False, autoincrement=True),
+            sa.Column("session_id", sa.Integer(), nullable=False),
+            sa.Column("role", sa.String(16), nullable=False),
+            sa.Column("content", sa.Text(), nullable=False),
+            sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+            sa.ForeignKeyConstraint(["session_id"], ["chat_sessions.id"], ondelete="CASCADE"),
+            sa.PrimaryKeyConstraint("id"),
+        )
+        op.create_index(op.f("ix_messages_session_id"), "messages", ["session_id"], unique=False)
+
+
+def downgrade() -> None:
+    op.drop_index(op.f("ix_messages_session_id"), table_name="messages")
+    op.drop_table("messages")
+    op.drop_index(op.f("ix_chat_sessions_external_user_id"), table_name="chat_sessions")
+    op.drop_table("chat_sessions")