new.字段 oracle

CREATE OR REPLACE TRIGGER update_salary BEFORE INSERT OR UPDATE on employees FOR EACH ROW BEGIN IF :new.salary

“new.”字段在触发器中的另一个常见用途是在insert语句中设置默认值。当执行insert语句时,Oracle首先会执行触发器,如果触发器中定义了“new.”字段,则会将其值设置为默认值。下面是一个示例:

CREATE OR REPLACE TRIGGER set_default_values BEFORE INSERT on employees FOR EACH ROW BEGIN IF :new.hire_date IS NULL THEN :new.hire_date := SYSDATE; END IF; IF :new.salary IS NULL THEN :new.salary := 5000; END IF; END;