Example: Using a SET Clause - Advanced SQL Engine - Teradata Database

This example uses a SET clause as a triggered action statement in a BEFORE row trigger.

This is the subject table definition. Assume that values are loaded into the amount column of the table from a source file employing a USING INSERT request.

     CREATE TABLE subject_table (        entry_date DATE,        amount     INTEGER); 

This is the trigger definition:

     CREATE TRIGGER set_trig        BEFORE INSERT ON subject_table        REFERENCING NEW AS curr_value        FOR EACH ROW        SET curr_value.entry_date = DATE;        -- Adds the current system date to the entry_date column

Because of the SET clause assignment, the following triggering statement:

     USING (amount INTEGER)      INSERT INTO subject_table VALUES (NULL,:amount); 

executes as if it were this statement:

     USING (thisdate DATE, amount INTEGER)      INSERT INTO subject_table VALUES (:thisdate, :amount);