SQL/MX 2.x Reference Manual (H06.04+)

SQL/MX Statements
HP NonStop SQL/MX Reference Manual—540440-003
2-97
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. 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.