add db migration script

migrations/versions/2020_022722_75093e7ded27_.py

@@ -0,0 +1,50 @@
+"""empty message
+
+Revision ID: 75093e7ded27
+Revises: e3cb44b953f2
+Create Date: 2020-02-27 22:26:25.068117
+
+"""
+import sqlalchemy_utils
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '75093e7ded27'
+down_revision = 'e3cb44b953f2'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('social_auth',
+    sa.Column('id', sa.Integer(), autoincrement=True, nullable=False),
+    sa.Column('created_at', sqlalchemy_utils.types.arrow.ArrowType(), nullable=False),
+    sa.Column('updated_at', sqlalchemy_utils.types.arrow.ArrowType(), nullable=True),
+    sa.Column('user_id', sa.Integer(), nullable=False),
+    sa.Column('social', sa.String(length=128), nullable=False),
+    sa.ForeignKeyConstraint(['user_id'], ['users.id'], ondelete='cascade'),
+    sa.PrimaryKeyConstraint('id'),
+    sa.UniqueConstraint('user_id', 'social', name='uq_social_auth')
+    )
+    op.alter_column('users', 'password',
+               existing_type=sa.VARCHAR(length=128),
+               nullable=True)
+    op.alter_column('users', 'salt',
+               existing_type=sa.VARCHAR(length=128),
+               nullable=True)
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.alter_column('users', 'salt',
+               existing_type=sa.VARCHAR(length=128),
+               nullable=False)
+    op.alter_column('users', 'password',
+               existing_type=sa.VARCHAR(length=128),
+               nullable=False)
+    op.drop_table('social_auth')
+    # ### end Alembic commands ###