Parent topic: SQL portability
SQL programming / SQL portability

GROUP BY clause

Some databases allow you to specify a column index in the GROUP BY clause:
SELECT a, b, sum(c) FROM table GROUP BY 1,2

This is not possible with all database servers:

Table 1. Database server support of GROUP BY column index
Database Server Type GROUP BY colindex, ... ?
Genero db No
IBM® DB2® UDB No
IBM Informix® (1) Yes
Microsoft™ SQL Server (2) No
MySQL Yes
Oracle Database Server No
PostgreSQL Yes
Sybase ASE No
SQLite Yes

Search for GROUP BY in your SQL statements and use explicit column names.

Parent topic: SQL portability