--异常处理---------------------------------------------------------// --预定义异常 --NO_DATA_FOUND 没有数据满足查询要求 --ZERO_DIVIDE 算术错误,如试图用0去除一个数 --INVALID_NUMBER 在要求数据的地方使用了非数据 --NOT_LOGGED_ON 没有连接上Oracle --TOO_MANY_ROWS SELECT INTO 返回多行记录 --VALUE_ERROR 遇到算术的、转换的、截去的或约束错误 --CURSOR_ALREADY_OPEN 试图打开一个已经打开的游标 --DUP_VAL_ON_INDEX 试图插入一个已经存在的唯一约束值 --LOGIN_DENIED 要求进入系统的请求被拒绝 --TIMEOUT_ON_RESOURCE 等待的系统时间已经超时 --OTHERS 其它异常 --NO_DATA_FOUND 异常-----------------------------------------------// --%TYPE是指定义一个变量和数据库中某个表的某个字段的数据类型一样 DECLARE v_name emp.ename%TYPE; BEGIN SELECT ename INTO v_name FROM emp WHERE empno='1234'; --异常发生,empno 中没有1234 DBMS_OUTPUT.PUT_LINE('Name is : ' || v_name); EXCEPTION WHEN NO_DATA_FOUND THEN DBMS_OUTPUT.PUT_LINE('No Data Found'); WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE('Unknown Error'); END; / --ZERO_DIVIDE 异常-------------------------------------------------// BEGIN DBMS_OUTPUT.PUT_LINE(5/0); --异常发生,不能被0除 EXCEPTION WHEN ZERO_DIVIDE THEN DBMS_OUTPUT.PUT_LINE('Can not divide zero'); WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE('Unknown Error'); END; / --TOO_MANY_ROWS 异常-----------------------------------------------// DECLARE no emp.empno%TYPE; name emp.ename%TYPE; dept emp.deptno%TYPE; BEGIN SELECT empno,ename,deptno INTO no,name,dept FROM emp WHERE empno = 7369; DBMS_OUTPUT.PUT_LINE('员工号 :' || no); DBMS_OUTPUT.PUT_LINE('员工名 :' || name); DBMS_OUTPUT.PUT_LINE('部门号 :' || dept); EXCEPTION WHEN NO_DATA_FOUND THEN DBMS_OUTPUT.PUT_LINE('7369雇员不存在'); --未找到数据 WHEN TOO_MANY_ROWS THEN DBMS_OUTPUT.PUT_LINE('有多个学员号是7369'); --返回多行 WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE('Unknown Error'); END; / --DUP_VAL_ON_INDEX 异常--------------------------------------------// BEGIN INSERT INTO emp VALUES('7788','LaoZhao','Soft','7689','03-12月-81','2600','0','20'); EXCEPTION WHEN DUP_VAL_ON_INDEX THEN DBMS_OUTPUT.PUT_LINE('违反了PRIMARY KEY约束:7788雇员已经存在'); WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE('Unknown Error'); END; / -------------------------------------------------------------------// --如果员工7788的工资小于3000,则更新为3000,如未找到该雇员,则利用异常处理打印相应信息 DECLARE salary emp.sal%TYPE; BEGIN SELECT sal INTO salary FROM emp WHERE empno='7788'; IF salary < 3000 THEN UPDATE emp SET sal = '3000' WHERE empno = '7788'; DBMS_OUTPUT.PUT_LINE('记录已更新'); ELSE DBMS_OUTPUT.PUT_LINE('IF 条件不成立'); END IF; EXCEPTION WHEN NO_DATA_FOUND THEN DBMS_OUTPUT.PUT_LINE('7788雇员不存在'); WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE('Unknown Error'); END; / --用户自定义异常---------------------------------------------------// --001 DECLARE --v_num1 NUMBER:=5; v_num1 NUMBER:=0; --v_num2 NUMBER:=0; v_num2 NUMBER:=5; MyException EXCEPTION; BEGIN DBMS_OUTPUT.PUT_LINE(v_num1/v_num2); RAISE MyException; --引发自定义异常 DBMS_OUTPUT.PUT_LINE('OK'); --此句永远不会执行,因为发生异常后程序将直接跳到EXCEPTION段 EXCEPTION WHEN MyException THEN DBMS_OUTPUT.PUT_LINE('Cannot Divide Zero'); --WHEN ZERO_DIVIDE THEN -- DBMS_OUTPUT.PUT_LINE('Can not Divide Zero'); WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE('Unknown Error'); END; / --002 DECLARE id score.id%TYPE; java score.java%TYPE; MyException EXCEPTION; BEGIN SELECT id,java INTO id,java FROM score WHERE id = 4; IF java < 0 OR java > 100 THEN RAISE MyException; ELSE DBMS_OUTPUT.PUT_LINE('OK'); END IF; EXCEPTION WHEN MyException THEN UPDATE score SET java=0 WHERE id = 4; DBMS_OUTPUT.PUT_LINE('分数不能大于100或小于0,现已经清0'); WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE('Unknown Error'); END; / --003 DECLARE v_date emp.hiredate%TYPE; MyException EXCEPTION; BEGIN INSERT INTO emp(empno,hiredate) VALUES(1111,TO_DATE('2010-12-25','yyyy-mm-dd')); COMMIT; SELECT hiredate INTO v_date FROM emp WHERE empno=1111; IF v_date > SYSDATE THEN RAISE MyException; END IF; DBMS_OUTPUT.PUT_LINE('执行完毕'); EXCEPTION WHEN MyException THEN DBMS_OUTPUT.PUT_LINE('雇用日期不能大于当前日期'); --raise_application_error(-20002,'雇用日期不能大于当前日期'); UPDATE emp SET hiredate = SYSDATE WHERE empno = 1111; DBMS_OUTPUT.PUT_LINE('日期已更新为当前日期'); WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE('Unknown Error'); END; / --将定义好的异常与标准的ORACLE错误联系起来-------------------------// --001 DECLARE MyException EXCEPTION; PRAGMA EXCEPTION_INIT(MyException,-00001); --关联语句 BEGIN INSERT INTO emp(empno) VALUES(1234); --发生异常,企图插入有Check约束的重复值 COMMIT; --插入后提交 DBMS_OUTPUT.PUT_LINE('插入正常'); EXCEPTION WHEN MyException THEN DBMS_OUTPUT.PUT_LINE('ORA-00001: 违反了唯一约束'); WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE('Unknown Error'); END; / --002 CREATE TABLE a ( id INT NOT NULL, name VARCHAR2(20) NOT NULL ); DECLARE MyException EXCEPTION; PRAGMA EXCEPTION_INIT(MyException,-1400); --关联语句 BEGIN INSERT INTO a(id) VALUES(1); --发生异常,违反了NOT NULL约束 EXCEPTION WHEN MyException THEN DBMS_OUTPUT.PUT_LINE('错误代号:-1400'); DBMS_OUTPUT.PUT_LINE('错误描述:违反了NOT NULL约束'); DBMS_OUTPUT.PUT_LINE('错误发生时间:' || TO_CHAR(SYSDATE,'yyyy-mm-dd hh24:mi:ss')); INSERT INTO errinfo VALUES('-1400','违反了 NOT NULL约束',TO_CHAR(SYSDATE,'yyyy-mm-dd hh24:mi:ss')); DBMS_OUTPUT.PUT_LINE('已经将错误记录在ErrInfo表'); WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE('Unknown Error'); END; / --003 DECLARE MyException EXCEPTION; salary emp.sal%TYPE; BEGIN SELECT sal INTO salary FROM emp WHERE empno = '7788'; IF salary > 2000 THEN RAISE MyException; END IF; EXCEPTION WHEN MyException THEN RAISE_APPLICATION_ERROR(-20001,'RAISE_APPLICATION_ERROR异常发生',FALSE); --TRUE WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE('Unknown Error'); END; / --课后练习---------------------------------------------------------// --001 DECLARE gz emp.sal%TYPE; MyExc EXCEPTION; BEGIN SELECT sal INTO gz FROM emp WHERE ename='SCOTT'; DBMS_OUTPUT.PUT_LINE('原工资 : ' || gz); IF gz < 2000 THEN RAISE MyExc; ELSE DBMS_OUTPUT.PUT_LINE('工资无需更新'); END IF; EXCEPTION WHEN MyExc THEN UPDATE emp SET sal = 3000 WHERE ename='SCOTT'; DBMS_OUTPUT.PUT_LINE('记录已经更新'); SELECT sal INTO gz FROM emp WHERE ename='SCOTT'; DBMS_OUTPUT.PUT_LINE('更新后工资 : ' || gz); WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE('Unknown Error'); END; / --002 DECLARE lo salgrade.losal%TYPE; hi salgrade.hisal%TYPE; MyExc EXCEPTION; BEGIN INSERT INTO salgrade VALUES(6,2600,2400); COMMIT; SELECT losal,hisal INTO lo,hi FROM salgrade WHERE grade = 6; IF lo > hi THEN RAISE MyExc; ELSE DBMS_OUTPUT.PUT_LINE('记录已经插入'); END IF; EXCEPTION WHEN MyExc THEN --删除插入的记录并打印相应信息 delete salgrade WHERE grade = 6; DBMS_OUTPUT.PUT_LINE('记录插入失败 LOSAL 必须小于 HISAL'); WHEN OTHERS THEN DBMS_OUTPUT.PUT_LINE('Unknown Error'); END; / --附注-------------------------------------------------------------// --如需在PL\SQL中进行值输入, DECLARE num LONG; BEGIN num := '&num'; DBMS_OUTPUT.PUT_LINE('Input value is : ' || num); END; / --注意:如果要使你在DBMS_OUTPUT.PUT_LINE(...)中显示的语句得以显示,则必须显示的调用 SET SERVEROUTPUT ON; ----------------------------------------------------------------------------------End//
本文来自:http://javato.iteye.com/blog/78060