HP 3000 Manuals HP 3000 Manuals
The SQLEXPLAIN Command HP ALLBASE/4GL requires a slightly modified form of the SQLEXPLAIN command in SQL logic blocks. The SQLEXPLAIN command allows you to retrieve the text of HP ALLBASE/SQL error messages into the communication area field *ERROR. The format for the SQLEXPLAIN command is simply SQLEXPLAIN; You cannot use a host variable reference with the SQLEXPLAIN command in an SQL logic block. When HP ALLBASE/SQL detects an error at run-time, HP ALLBASE/4GL executes one SQLEXPLAIN command automatically. This command retrieves the text of the error message into *ERROR, and the error number, plus 100000, into the communication area field *IOSTATUS. In some cases, a single SQL statement can cause multiple SQL error messages. You can use further SQLEXPLAIN commands to retrieve the text and number of subsequent error messages. After the last error message has been retrieved, a further SQLEXPLAIN command returns an empty string to *ERROR and sets *IOSTATUS to zero.