Outer joins

Use standard ISO outer join syntax instead of the old IBM^® Informix^® OUTER() syntax.

Old IBM Informix SQL outer joins specified with the OUTER keyword in the FROM part are not standard:

SELECT * FROM master, OUTER ( detail )
  WHERE master.mid = detail.mid
    AND master.cdate IS NOT NULL

Table 1. Database server support of OUTER JOIN syntax
Database Server Type	Supports IBM Informix OUTER join syntax
Genero db	Yes
IBM DB2^® UDB	No (but translated by driver)
IBM Informix (1)	Yes
Microsoft™ SQL Server (2)	No (but translated by driver)
MySQL	No (but translated by driver)
Oracle Database Server	No (but translated by driver)
PostgreSQL	No (but translated by driver)
Sybase ASE	No (but translated by driver)
SQLite	No (but translated by driver)

Most recent database servers now support the standard ANSI outer join specification:

SELECT * FROM master LEFT OUTER JOIN detail ON (master.mid = detail.mid)
  WHERE master.cdate IS NOT NULL

You should use recent database servers and use ANSI outer joins only.