Make migrations idempotent for production DB with pre-existing columns

Check for existing columns/tables before adding to avoid duplicate
column errors when production DB state is ahead of Alembic history.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

migrations/versions/2937635f309a_add_turn_tracking_fields_to_game_model.py

@@ -17,12 +17,22 @@ depends_on = None
 
 
 def upgrade():
-    # ### commands auto generated by Alembic - please adjust! ###
+    # Check which columns already exist to make migration idempotent
-    # Split into two batch operations to avoid SQLite circular dependency error
+    conn = op.get_bind()
+    columns = [row[1] for row in conn.execute(sa.text("PRAGMA table_info('games')"))]
+
+    cols_to_add = []
+    if 'current_turn_team_id' not in columns:
+        cols_to_add.append(sa.Column('current_turn_team_id', sa.Integer(), nullable=True))
+    if 'turn_order' not in columns:
+        cols_to_add.append(sa.Column('turn_order', sa.JSON(), nullable=True))
+    if 'is_steal_mode' not in columns:
+        cols_to_add.append(sa.Column('is_steal_mode', sa.Boolean(), nullable=True))
+
+    if cols_to_add:
         with op.batch_alter_table('games', schema=None) as batch_op:
-        batch_op.add_column(sa.Column('current_turn_team_id', sa.Integer(), nullable=True))
+            for col in cols_to_add:
-        batch_op.add_column(sa.Column('turn_order', sa.JSON(), nullable=True))
+                batch_op.add_column(col)
-        batch_op.add_column(sa.Column('is_steal_mode', sa.Boolean(), nullable=True))
 
     with op.batch_alter_table('games', schema=None) as batch_op:
         batch_op.create_foreign_key('fk_games_current_turn_team', 'teams', ['current_turn_team_id'], ['id'])

migrations/versions/9a119272b516_add_question_ownership_and_sharing.py

@@ -18,6 +18,11 @@ depends_on = None
 
 def upgrade():
     # ### commands auto generated by Alembic - please adjust! ###
+    conn = op.get_bind()
+
+    # Create question_shares table if it doesn't exist
+    tables = [row[0] for row in conn.execute(sa.text("SELECT name FROM sqlite_master WHERE type='table'"))]
+    if 'question_shares' not in tables:
         op.create_table('question_shares',
         sa.Column('id', sa.Integer(), nullable=False),
         sa.Column('question_id', sa.Integer(), nullable=False),
@@ -30,16 +35,32 @@ def upgrade():
         sa.PrimaryKeyConstraint('id'),
         sa.UniqueConstraint('question_id', 'shared_with_user_id', name='unique_question_share')
         )
-    # Split into separate batch operations to avoid SQLite circular dependency
-    # with the existing current_turn_team_id foreign key
-    with op.batch_alter_table('games', schema=None) as batch_op:
-        batch_op.add_column(sa.Column('completed_at', sa.DateTime(), nullable=True))
-        batch_op.add_column(sa.Column('winners', sa.JSON(), nullable=True))
 
-    with op.batch_alter_table('games', schema=None) as batch_op:
+    # Check existing columns to make migration idempotent
-        batch_op.drop_column('turn_order')
+    game_columns = [row[1] for row in conn.execute(sa.text("PRAGMA table_info('games')"))]
-        batch_op.drop_column('is_steal_mode')
+    question_columns = [row[1] for row in conn.execute(sa.text("PRAGMA table_info('questions')"))]
 
+    # Add new game columns if missing
+    game_cols_to_add = []
+    if 'completed_at' not in game_columns:
+        game_cols_to_add.append(sa.Column('completed_at', sa.DateTime(), nullable=True))
+    if 'winners' not in game_columns:
+        game_cols_to_add.append(sa.Column('winners', sa.JSON(), nullable=True))
+
+    if game_cols_to_add:
+        with op.batch_alter_table('games', schema=None) as batch_op:
+            for col in game_cols_to_add:
+                batch_op.add_column(col)
+
+    # Drop old game columns if they still exist
+    game_cols_to_drop = [c for c in ['turn_order', 'is_steal_mode'] if c in game_columns]
+    if game_cols_to_drop:
+        with op.batch_alter_table('games', schema=None) as batch_op:
+            for col_name in game_cols_to_drop:
+                batch_op.drop_column(col_name)
+
+    # Add created_by to questions if missing
+    if 'created_by' not in question_columns:
         with op.batch_alter_table('questions', schema=None) as batch_op:
             batch_op.add_column(sa.Column('created_by', sa.Integer(), nullable=True))
             batch_op.create_foreign_key('fk_questions_created_by', 'users', ['created_by'], ['id'])