Mysql on case-insensitive file systems (default on Mac OS X):
The following entity will cause overlapping column names:

entity Test{
  test -> List<Test>
}

var s1 := Test{}
var s2 := Test{test:=[s1]}

exception:

Caused by: java.sql.BatchUpdateException: Column '_Test_id' specified twice

Submitted by Danny Groenewegen on 28 June 2010 at 16:39