Unexpected token “LIMIT” in DB2

Question

My Rails app is connected to a remote DB2 database, and when migrating I'm stumbling into this error:

==  DropLegacyProject: migrating ========================================
rake aborted!
An error has occurred, this and all later migrations canceled:

RuntimeError: Failed to execute statement due to: [IBM][CLI Driver][DB2/LINUXX8664] SQL0104N  An unexpected token "LIMIT" was found following "".  Expected tokens may include:  "FETCH FIRST <n> ROWS ONLY".  SQLSTATE=42601 SQLCODE=-104: SELECT  projects.* FROM projects WHERE projects.id < 17 LIMIT 1

How can I fix this?

Answer 1

As bhamby suggested, DB2 does not support the LIMIT x keyword... by default.

But starting with DB2 v9.7.2, support for LIMIT x can be enabled via the DB2_COMPATIBILITY_VECTOR registry variable:

db2set DB2_COMPATIBILITY_VECTOR=MYS
db2stop
db2start

...and it works!

Answer 2

DB2 does not support the LIMIT x keyword.

As the error message says, the proper way to do this would to use FETCH FIRST x ROWS ONLY instead.