Unit tests with mysql/postgres/mssql

[lunny]

Currently unit tests only with sqlite, so we needs run unit tests with mysql/postgres/mssql like we did on migration tests.

[lunny]

ref from #8347

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs during the next 2 weeks. Thank you for your contributions.

[yardenshoham]

Should this be closed?