Check index exists after create index. If not exists, return the err.
We run into this case, because we use the same index name for difference table, and the migration executed successfuly. But when use do some request, we got a err ERROR: there is no unique or exclusion constraint matching the ON CONFLICT specification (SQLSTATE 42P10 becase we must make sure the index exists.
What did this pull request do?
Check index exists after create index. If not exists, return the err.
We run into this case, because we use the same index name for difference table, and the migration executed successfuly. But when use do some request, we got a err
ERROR: there is no unique or exclusion constraint matching the ON CONFLICT specification (SQLSTATE 42P10
becase we must make sure the index exists.