make aliasUsedOn.user_id non nullable

app/models.py

@@ -850,7 +850,7 @@ class AliasUsedOn(db.Model, ModelMixin):
     )
 
     alias_id = db.Column(db.ForeignKey(Alias.id, ondelete="cascade"), nullable=False)
-    user_id = db.Column(db.ForeignKey(User.id, ondelete="cascade"), nullable=True)
+    user_id = db.Column(db.ForeignKey(User.id, ondelete="cascade"), nullable=False)
 
     alias = db.relationship(Alias)
 

migrations/versions/2020_032012_30c13ca016e4_.py

@@ -0,0 +1,33 @@
+"""empty message
+
+Revision ID: 30c13ca016e4
+Revises: 4e4a759ac4b5
+Create Date: 2020-03-20 12:28:12.901907
+
+"""
+import sqlalchemy_utils
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '30c13ca016e4'
+down_revision = '4e4a759ac4b5'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.alter_column('alias_used_on', 'user_id',
+               existing_type=sa.INTEGER(),
+               nullable=False)
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.alter_column('alias_used_on', 'user_id',
+               existing_type=sa.INTEGER(),
+               nullable=True)
+    # ### end Alembic commands ###