oracle函数与触发器

--1.无参函数

CREATE OR REPLACE FUNCTION func1 RETURN VARCHAR2

IS

BEGIN

RETURN '欢迎你:'||USER||',现在是:'||to_char(SYSDATE,'yyyy-mm-dd');

END func1;

--调用测试

BEGIN

dbms_output.put_line(func1);

END;

--有参函数

SELECT * FROM emp;

CREATE OR REPLACE FUNCTION getWorkTime(hiredate DATE) RETURN NUMBER

IS

BEGIN

RETURN trunc(months_between(SYSDATE,hiredate)/12);

END getWorkTime;

SELECT ename,job,getWorkTime(hiredate) FROM emp;

--触发器

--语句触发器(select/insert/update/delete)

CREATE OR REPLACE TRIGGER trg_dept BEFORE INSERT OR UPDATE OR DELETE ON dept

DECLARE

BEGIN

dbms_output.put_line(USER||','||to_char(SYSDATE,'yyyy-mm-dd')||',对dept进行操作。');

END trg_dept;

UPDATE dept SET dname='测试' WHERE deptno=60;

INSERT INTO dept VALUES(23,'触发器','数据库');

--行触发器(FOR EACH ROW)

--before触发器

--伪记录 :NEW :OLD

--3个条件谓词：INSERTING UPDATING DELETING

CREATE OR REPLACE TRIGGER trg_dept_before

BEFORE INSERT OR UPDATE OR DELETE ON dept

FOR EACH ROW

DECLARE

v_now VARCHAR2(50);

BEGIN

v_now:=to_char(SYSDATE,'yyyy-mm-dd hh24:mi:ss');

CASE

WHEN INSERTING THEN

dbms_output.put_line(v_now||'对dept表进行了添加操作');

dbms_output.put_line('添加的数据:'||:new.deptno||','||:new.dname||','||:new.loc);

WHEN UPDATING THEN

dbms_output.put_line(v_now||'对dept表进行了修改操作');

dbms_output.put_line('修改之前的数据:'||:old.deptno||','||:old.dname||','||:old.loc);

dbms_output.put_line('修改之后的数据:'||:new.deptno||','||:new.dname||','||:new.loc);

WHEN DELETING THEN

dbms_output.put_line(v_now||'对dept表进行了删除操作');

dbms_output.put_line('删除的数据:'||:old.deptno||','||:old.dname||','||:old.loc);

END CASE;

END trg_dept_before;

INSERT INTO dept VALUES(24,'触发器4','数据库4');

UPDATE dept SET dname='测试' WHERE deptno=24;

DELETE FROM dept WHERE deptno=24;

COMMIT;

--实现SQL Server中标识列效果

CREATE SEQUENCE seq_dept_deptno INCREMENT BY 1 START WITH 100 MAXVALUE 999999 NOCYCLE;

--触发器（从序列里面取值，并且在insert语句进行使用

CREATE OR REPLACE TRIGGER trg_dept_before_increment

BEFORE INSERT ON dept FOR EACH ROW

BEGIN

SELECT seq_dept_deptno.nextval INTO :new.deptno FROM dual;

END trg_dept_before_increment;

INSERT INTO dept (dname,loc) VALUES('序列','序列');

--INSERT INTO dept (deptno,dname,loc) VALUES(seq_dept_deptno.nextval,'序列','序列');

COMMIT;

--使用after触发器记录数据操作日志

CREATE TABLE dept_log(

uname VARCHAR2(40),

oper_time DATE,

oper_type VARCHAR2(20),

info VARCHAR2(100)

);

CREATE OR REPLACE TRIGGER trg_dept_after

AFTER INSERT OR DELETE ON dept FOR EACH ROW

DECLARE

v_info VARCHAR2(100);

BEGIN

CASE

WHEN inserting THEN

v_info:= :new.deptno||','||:new.dname||','||:new.loc;

INSERT INTO dept_log VALUES(USER,SYSDATE,'insert',v_info);

WHEN deleting THEN

v_info:= :old.deptno||','||:old.dname||','||:old.loc;

INSERT INTO dept_log VALUES(USER,SYSDATE,'delete',v_info);

END CASE;

END trg_dept_after;

INSERT INTO dept VALUES(35,'sales','青岛');

DELETE FROM dept WHERE deptno=35;

COMMIT;

SELECT * FROM dept_log;

SELECT * FROM emp;

--根据列进行触发update of

CREATE OR REPLACE TRIGGER trg_emp_sal_update

BEFORE UPDATE OF sal ON emp FOR EACH ROW

BEGIN

IF :new.sal<:old.sal THEN

dbms_output.put_line('职工工资不能向低调整.');

raise_application_error(-20009,'职工工资不能向低调整.');

END IF;

END trg_emp_sal_update;

UPDATE emp SET sal=10000 WHERE empno=7369;

SELECT * FROM emp WHERE empno=7369;

--按行触发（所有进行触发）when

CREATE OR REPLACE TRIGGER trg_emp_when

AFTER INSERT OR DELETE ON emp FOR EACH ROW

WHEN (new.deptno=10 AND new.deptno<=30)

DECLARE

v_info VARCHAR2(100);

BEGIN

CASE

WHEN inserting THEN

v_info:= :new.ename||','||:new.job||','||:new.sal;

INSERT INTO dept_log VALUES(USER,SYSDATE,'insert',v_info);

WHEN deleting THEN

v_info:= :old.ename||','||:old.job||','||:old.sal;

INSERT INTO dept_log VALUES(USER,SYSDATE,'delete',v_info);

END CASE;

END trg_emp_when;

INSERT INTO emp VALUES(1111,'test1','test',1111,SYSDATE,1111,0,10);

INSERT INTO emp VALUES(1112,'test2','test',1112,SYSDATE,1111,0,50);

COMMIT;

SELECT * FROM dept_log;

ALTER TRIGGER trg_emp_when DISABLE;

ALTER TRIGGER trg_emp_when ENABLE;

SELECT * FROM user_triggers WHERE table_name='DEPT';

--cmd 命令窗口 切换到C:\oracle\product\10.2.0\db_1\bin目录

--导出：

EXP scott/tiger BUFFER=64000 FILE=d:/scott.dmp

--导入

imp scott/tiger FILE=d:/scott.dmp FULL=y IGNORE=y