feat: support binding context var (#1227)

Co-authored-by: Joel <iamjoel007@gmail.com>

api/migrations/versions/ab23c11305d4_add_dataset_query_variable_at_app_model_.py

@@ -0,0 +1,31 @@
+"""add dataset query variable at app model configs.
+
+Revision ID: ab23c11305d4
+Revises: 6e2cfb077b04
+Create Date: 2023-09-26 12:22:59.044088
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision = 'ab23c11305d4'
+down_revision = '6e2cfb077b04'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table('app_model_configs', schema=None) as batch_op:
+        batch_op.add_column(sa.Column('dataset_query_variable', sa.String(length=255), nullable=True))
+
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table('app_model_configs', schema=None) as batch_op:
+        batch_op.drop_column('dataset_query_variable')
+
+    # ### end Alembic commands ###