SQL/MX 2.x Reference Manual (G06.24+, H06.03+)

SQL/MX Statements
HP NonStop SQL/MX Reference Manual—523725-004
2-98
Considerations for CREATE TRIGGER
insert-statement
is an insert statement to be performed when this trigger is activated.
signal-statement
is a statement to be sent to the SIGNAL statement.
set-new-statement
is an assignment statement that can be used as a BEFORE-trigger action to
assign values to transition variables representing columns in the subject table
modified by the triggering action.
quoted-sqlstate
is the five-digit SQLSTATE to be passed to SIGNAL. Use the GET DIAGNOSTICS
command to retrieve quoted-string-expr (as message-text) and
quoted-sqlstate.
quoted-string-expr
is a string expression.
Considerations for CREATE TRIGGER
Triggers support up to 16 levels of recursion. Triggers have their own namespace.
SHOWDDL displays the DDL CREATE text for all triggers. Comment: The LIKE option
of CREATE TABLE ignores triggers.
Triggers and Utilities
•
The DUP utility does not duplicate triggers.
•
By default, importing data into a table causes trigger actions to be performed. Use
the -d option, which allows triggers to be disabled for the duration of the operation.
•
Most of MODIFY’s partition management operations ignore triggers. However, the
REUSE form of MODIFY might return errors on a table with DELETE triggers.
•
Use PURGEDATA to purge the data of a table that is referenced by a trigger or that
is the subject of a trigger. PURGEDATA supports an option that indicates whether
DELETE triggers on the table are ignored. If they are not ignored and a DELETE
trigger exists, PURGEDATA fails.
•
BACKUP/RESTORE operations ignore triggers.
•
The mxexportddl utility handles triggers correctly.
•
VERIFY operations ignore triggers.