What are triggers?

Answer 1

Triggers are an action that is performed is a condition is met within the code. In this example, "TRIG56" will perform this action: After a row is inserted into TABLEZZZ, if the row is <=50 then

insert the same row into TABLEYYY. If the condition/value is not

met, the row will not be inserted.

You can do a "BEFORE" trigger also. Triggers are code that must be compiled. You can also "disable" a trigger if you are doing an import into the tables for faster insertion. However, the inserts will have to be done into both tables because TABLEYYY will not be populated from the trigger because it is disabled. CREATE TRIGGER trig56 AFTER INSERT ON tableZZZ REFERENCING NEW AS insertedRow FOR EACH ROW WHEN (insertedRow.a <= 50) BEGIN INSERT INTO tableYYY VALUES(:insertedRow.b, :insertedRow.a); END trig56; . run;
Trigger is a statement that excute automatically as a side effect of modification to the database.
A trigger is defined for and connected to a RDBMS table. A trigger can be defined to do a particular job (typically insert audit records in another table or perform some validations) whenever the original table (on which the trigger is created) is selected or inserted, updated or deleted. A trigger is used to ensure that certain jobs are automatically done when a predefined event occurs. Both the event and the resultant action typically happen within the database.

A trigger is a set of statements that gets executed implicitly or automatically whenever any one of the following operation takes place on the table for which trigger has been created :

1. Inserting record(s) to the table

2. Deleting record(s) from the table

3. Updating the table

The operation on which trigger gets executed and the work performed at that time depends on the statements written in the trigger.