Oracle触发器的简单使用

2013-01-31

　　今天学习了点oracle，触发器的简单使用，需要解决的问题是如下，还是英文描述吧。

the triggers are perfect is change auditing.The example is of Paranoid Pam(who runs a bowling alley and have been receiving complaints about people cheating on their scores).she recently complete an oracle application to catch the cheaters.

simply say, she just want to find who and when and how change the data.

next, you will say my PL/SQL code.in the write i have use some may useful method to make it.

souce code:

  1 --好的创建表的方法
  2 DECLARE
  3   TB NUMBER;
  4 BEGIN
  5   SELECT COUNT(*) INTO TB FROM TABS WHERE TABLE_NAME = 'FRAME';
  6   IF TB <> 0 THEN
  7     EXECUTE IMMEDIATE 'DROP TABLE frame';
  8     EXECUTE IMMEDIATE '
  9     CREATE TABLE frame
 10     (
 11        bowler_id number,
 12        game_id number,
 13        frame_id number,
 14        strike varchar2(1) default ''N'',
 15        spare varchar2(1) default ''N'',
 16        score number,
 17        constraint frame_pk
 18        primary key (bowler_id,game_id,frame_id)
 19     )';
 20     DBMS_OUTPUT.PUT_LINE('存在该表已删除，并创建新的表');
 21   ELSE
 22     EXECUTE IMMEDIATE 'CREATE TABLE frame
 23     (
 24        bowler_id number,
 25        game_id number,
 26        frame_id number,
 27        strike varchar2(1) default ''N'',
 28        spare varchar2(1) default ''N'',
 29        score number,
 30        constraint frame_pk
 31        primary key (bowler_id,game_id,frame_id)
 32     )';
 33     DBMS_OUTPUT.PUT_LINE('不存在该表，已创建新表');
 34   END IF;
 35 END;
 36 
 37 --创建审计表
 38 DECLARE
 39   TB NUMBER;
 40 BEGIN
 41   SELECT COUNT(*) INTO TB FROM TABS WHERE TABLE_NAME = 'FRAME_AUDIT';
 42   IF TB <> 0 THEN
 43     EXECUTE IMMEDIATE 'DROP TABLE frame_audit';
 44     EXECUTE IMMEDIATE '
 45     CREATE TABLE frame_audit
 46     (
 47            bowler_id NUMBER,
 48            game_id NUMBER,
 49            frame_id NUMBER,
 50            old_strike VARCHAR2(1),
 51            new_strike VARCHAR2(1),
 52            
 53            old_spare VARCHAR2(1),
 54            new_spare VARCHAR2(1),
 55            
 56            old_score VARCHAR2(1),
 57            new_score VARCHAR2(1),
 58            
 59            change_date DATE,
 60            operation VARCHAR2(6) 
 61     )';
 62     DBMS_OUTPUT.PUT_LINE('存在该表已删除，并创建新的表');
 63   ELSE
 64     EXECUTE IMMEDIATE 'CREATE TABLE frame_audit
 65                   (
 66                          bowler_id NUMBER,
 67                          game_id NUMBER,
 68                          frame_id NUMBER,
 69                          old_strike VARCHAR2(1),
 70                          new_strike VARCHAR2(1),
 71                          
 72                          old_spare VARCHAR2(1),
 73                          new_spare VARCHAR2(1),
 74                          
 75                          old_score VARCHAR2(1),
 76                          new_score VARCHAR2(1),
 77                          
 78                          change_date DATE,
 79                          operation VARCHAR2(6) 
 80                   )';
 81     DBMS_OUTPUT.PUT_LINE('不存在该表，已创建新表');
 82   END IF;
 83 END;
 84 
 85 
 86 --创建触发器
 87 CREATE OR REPLACE TRIGGER audit_frames
 88 AFTER INSERT OR UPDATE OR DELETE ON frame
 89 FOR EACH ROW
 90   BEGIN
 91     IF inserting THEN
 92       INSERT INTO frame_audit(bowler_id,game_id,frame_id,
 93        new_strike,new_spare,
 94        new_score,change_date,operation)
 95       VALUES(:new.bowler_id,:new.game_id,:new.frame_id,:new.strike,:new.spare,:new.score,SYSDATE,'insert');
 96       
 97       ELSIF updating THEN
 98       INSERT INTO frame_audit(bowler_id,game_id,frame_id,
 99       old_strike,new_strike,old_spare,new_spare,
100       old_score,new_score,change_date,operation)
101       VALUES(:new.bowler_id,:new.game_id,:new.frame_id,:old.strike,:new.strike,:old.spare,:new.spare,:old.score,:new.score,SYSDATE,'update');
102       
103       ELSIF deleting THEN
104       INSERT INTO frame_audit(bowler_id,game_id,frame_id,
105        old_strike,old_spare,
106        old_score,change_date,operation)
107       VALUES(:old.bowler_id,:old.game_id,:old.frame_id,:old.strike,:old.spare,:old.score,SYSDATE,'insert');
108       
109       END IF;
110       END audit_frames;
111 
112 --在创建之后，后来使用的时候报了一个触发器无效且未通过认证的错误
113 --解决办法是找到触发器-》右键查看-》找到相应的错误（insert->inserting）.问题解决。
114 
115 
116 INSERT INTO frame (bowler_id,game_id,frame_id,strike)
117 VALUES (1,2,3,'y');
118 
119 
120 SELECT * FROM frame;
121 
122 UPDATE frame SET strike ='N',
123 spare = 'y'
124 WHERE bowler_id =1
125 AND game_id =2
126 AND frame_id =3;
127 
128 DELETE frame WHERE bowler_id = 1;
129 
130 COMMIT;
131 
132 SELECT * FROM frame;
133 
134 SELECT * FROM frame_audit;

代码可以放在pl/sql的sql脚本中运行，可以看到相应的结果。