add sql migration

migrations/versions/2020_062513_a3c9a43e41f4_.py

@@ -0,0 +1,31 @@
+"""empty message
+
+Revision ID: a3c9a43e41f4
+Revises: a5b4dc311a89
+Create Date: 2020-06-25 13:02:21.128994
+
+"""
+import sqlalchemy_utils
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'a3c9a43e41f4'
+down_revision = 'a5b4dc311a89'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('users', sa.Column('default_random_alias_domain_id', sa.Integer(), nullable=True))
+    op.create_foreign_key(None, 'users', 'custom_domain', ['default_random_alias_domain_id'], ['id'])
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_constraint(None, 'users', type_='foreignkey')
+    op.drop_column('users', 'default_random_alias_domain_id')
+    # ### end Alembic commands ###