I have used CONCAT a lot in different databases. For example CONCAT("name",CONCAT(' ',"surname")) to combine names). It creates many errors when trying to convert my bases to Firebird and it took me some time to find out what was the problem. This CONCAT function is not recognised by Firebird. It should be converted correctly to || syntax. For example: CONCAT("name",CONCAT(' ',"surname")) => "name" || ' ' || "surname" Or user should at least receive a warning or some indications about how to modfy their queries.
*** This bug has been marked as a duplicate of bug 117090 ***