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

ORACLE

Oracle provides the DUAL table to produce a single row result set:

SELECT USER FROM DUAL
Starting with Oracle 23c, it is possible to omit the FROM clause:
SELECT 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.