dektrium/yii2-user — pull request #192 by belerophon (2014-12-12 15:02:27+00:00)
Title: replacing unsigned integer type with a CHECK constraint when using postg...

Original migration fails on Postgresql, because unsigned integer does not seem to be a valid type (not SQL standard; not implemented on Postgresql...?)

The commit uses a check constraint to force unsigned integers, when usign Postgresql.