菜鸟问题,谁能提供一个创建触发器的sql脚本

CREATE OR REPLACE TRIGGER OnlyPositive
BEFORE INSERT OR UPDATE OF num_col
ON temp_table
FOR EACH ROW
BEGIN
IF :new.num_col < 0 THEN
RAISE_APPLICATION_ERROR(-20100, 'Please insert a positive value');
END IF;
END OnlyPositive;
/

CREATE OR REPLACE TRIGGER LOGIN_ON_INFO
AFTER LOGON ON SCHEMA
BEGIN
INSERT INTO LOGIN_LOG(SESSION_ID,LOGIN_ON_TIME,LOGIN_OFF_TIME,USER_IN_DB,MACHINE,IP_ADDRESS,RUN_PROGRAM)
SELECT AUDSID,SYSDATE,NULL,SYS.LONG_USER,MACHINE,SYS_CONTEXT('USERENV','IP_ADDRESS'),PROGRAM
FROM V$SESSION WHERE AUDSID=USERENV('SESSIONID'); --当前的 SESSION
END LOGIN_ON_INFO;