refac: convert chat.chat to json data type

backend/open_webui/migrations/versions/242a2047eae0_update_chat_table.py

@@ -0,0 +1,82 @@
+"""Update chat table
+
+Revision ID: 242a2047eae0
+Revises: 6a39f3d8e55c
+Create Date: 2024-10-09 21:02:35.241684
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.sql import table, select, update
+
+import json
+
+revision = "242a2047eae0"
+down_revision = "6a39f3d8e55c"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # Step 1: Rename current 'chat' column to 'old_chat'
+    op.alter_column("chat", "chat", new_column_name="old_chat", existing_type=sa.Text)
+
+    # Step 2: Add new 'chat' column of type JSON
+    op.add_column("chat", sa.Column("chat", sa.JSON(), nullable=True))
+
+    # Step 3: Migrate data from 'old_chat' to 'chat'
+    chat_table = table(
+        "chat",
+        sa.Column("id", sa.String, primary_key=True),
+        sa.Column("old_chat", sa.Text),
+        sa.Column("chat", sa.JSON()),
+    )
+
+    # - Selecting all data from the table
+    connection = op.get_bind()
+    results = connection.execute(select(chat_table.c.id, chat_table.c.old_chat))
+    for row in results:
+        try:
+            # Convert text JSON to actual JSON object, assuming the text is in JSON format
+            json_data = json.loads(row.old_chat)
+        except json.JSONDecodeError:
+            json_data = None  # Handle cases where the text cannot be converted to JSON
+
+        connection.execute(
+            sa.update(chat_table)
+            .where(chat_table.c.id == row.id)
+            .values(chat=json_data)
+        )
+
+    # Step 4: Drop 'old_chat' column
+    op.drop_column("chat", "old_chat")
+
+
+def downgrade():
+    # Step 1: Add 'old_chat' column back as Text
+    op.add_column("chat", sa.Column("old_chat", sa.Text(), nullable=True))
+
+    # Step 2: Convert 'chat' JSON data back to text and store in 'old_chat'
+    chat_table = table(
+        "chat",
+        sa.Column("id", sa.String, primary_key=True),
+        sa.Column("chat", sa.JSON()),
+        sa.Column("old_chat", sa.Text()),
+    )
+
+    connection = op.get_bind()
+    results = connection.execute(select(chat_table.c.id, chat_table.c.chat))
+    for row in results:
+        text_data = json.dumps(row.chat) if row.chat is not None else None
+        connection.execute(
+            sa.update(chat_table)
+            .where(chat_table.c.id == row.id)
+            .values(old_chat=text_data)
+        )
+
+    # Step 3: Remove the new 'chat' JSON column
+    op.drop_column("chat", "chat")
+
+    # Step 4: Rename 'old_chat' back to 'chat'
+    op.alter_column("chat", "old_chat", new_column_name="chat", existing_type=sa.Text)