add migration script

app/models.py

@@ -915,7 +915,7 @@ class AccountActivation(db.Model, ModelMixin):
         db.ForeignKey(User.id, ondelete="cascade"), nullable=False, unique=True
     )
     # the activation code is usually 6 digits
-    code = db.Column(db.String(10), unique=True, nullable=False)
+    code = db.Column(db.String(10), nullable=False)
 
     # nb tries decrements each time user enters wrong code
     tries = db.Column(db.Integer, default=3, nullable=False)

migrations/versions/2020_022819_5f191273d067_.py

@@ -0,0 +1,40 @@
+"""empty message
+
+Revision ID: 5f191273d067
+Revises: 75093e7ded27
+Create Date: 2020-02-28 19:08:15.570326
+
+"""
+import sqlalchemy_utils
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '5f191273d067'
+down_revision = '75093e7ded27'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('account_activation',
+    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('code', sa.String(length=10), nullable=False),
+    sa.Column('tries', sa.Integer(), nullable=False),
+    sa.CheckConstraint('tries >= 0', name='account_activation_tries_positive'),
+    sa.ForeignKeyConstraint(['user_id'], ['users.id'], ondelete='cascade'),
+    sa.PrimaryKeyConstraint('id'),
+    sa.UniqueConstraint('user_id')
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_table('account_activation')
+    # ### end Alembic commands ###