Oracle plsql if updating redhot dating vancouver
NEXTVAL INTO : NEW.my_col3 FROM DUAL; END IF; IF : NEW.my_col4 IS NULL THEN (...) END IF; END; / CREATE OR REPLACE TRIGGER my_trg2 BEFORE UPDATE ON my_table FOR EACH ROW BEGIN IF : NEW.my_col IS NULL THEN raise_application_error(...); END IF; IF : NEW.my_col2 IS NULL THEN : NEW.my_col2 := (...); END IF; END; / I can't see any major advantage to one or the other.
The separate approach is slightly less risky in case of updates (e.g.
This article represents the bare minimum you should understand about triggers before you consider writing one.
clause define the timing point for the trigger, which is explained below.
Many applications update all of the columns in a table -- setting them to their old value, rather then trying to figure out exactly which columns have been updated by the client. create or replace trigger test_trigger 2 after update of x,y on test 3 for each row 4 begin 5 if updating( 'X' ) then 6 dbms_output.put_line( 'X is being updated' ); 7 end if; 8 9 if updating( 'Y' ) then 10 dbms_output.put_line( 'Y is being updated' ); 11 end if; 12 end; 13 / Trigger created.
SQL Notice in the last update it indicated that x and y both were being updated (which they were), but the update didn't change the value (both x and y were 1 prior to the update which set them to 1). You can use updating (column) but it will only tell you that the column itself is being updated and not if the value has changed.
Vishwanath Dalvi is a gifted engineer and tech enthusiast. When not hacking around or supporting the open source community, he is trying to overcome his phobia of dogs.There are optional declaration and exception sections, like any other PL/SQL block, if required.The "dml-event" can be one or more of the following.I have found this to be especially helpful when I or others have to troubleshoot the consequences of user data corruption as it relates to triggers being fired - the less triggers you have to try to piece together the logic for, the easier it is to see how data was manipulated. Obviously the separate triggers are more efficient because you're doing fewer logical checks, but you have a decent point on the benefit of having fewer triggers.
It works, but it won't tell you if the value changed, only that the column is being updated (even if the update doesn't change the value).
If the condition is TRUE, the statements get executed, and if the condition is FALSE or NULL, then the IF statement does nothing.