Single row SELECT

Informix®

With Informix, you must use the system table with a condition on the table id:

SELECT USER FROM systables WHERE tabid=1 

Microsoft™ SQL Server

With SQL Server, omit the FROM clause to generate one row only:
SELECT CURRENT_USER 

Solution

Check the BDL sources for "FROM systables WHERE tabid=1" and use dynamic SQL to resolve this problem.

Consider writing a FUNCTION which produces the FROM and WHERE part, depending on the target database type.