Add column "prior" with default value

migrations/versions/70547c924023_.py

@@ -18,8 +18,10 @@ depends_on = None
 
 def upgrade():
     # ### commands auto generated by Alembic - please adjust! ###
-    op.add_column('defaultmetas', sa.Column('prior', sa.Boolean(), nullable=False))
+    op.add_column('defaultmetas', sa.Column('prior', sa.Boolean(), nullable=True))
     op.add_column('defaultmetas', sa.Column('value', sa.String(), nullable=True))
+    op.execute("UPDATE defaultmetas SET prior=FALSE")
+    op.alter_column("defaultmetas", "prior", nullable=False)
     # ### end Alembic commands ###