mysql存储过程之游标遍历数据表

 1  BEGIN
 2      DECLARE Done INT DEFAULT 0;
 3     
 4      DECLARE CurrentLingQi INT;
 5     
 6      DECLARE ShizuName VARCHAR(30);
 7      /* 声明游标 */
 8      DECLARE rs CURSOR FOR SELECT NodeName, LingQi FROM socialrelation;
 9      /* 异常处理 */
10      DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET Done = 1;
11     
12      /* 打开游标 */
13      OPEN rs;  
14     
15      /* 逐个取出当前记录LingQi字段的值，需要进行最大值的判断 */
16      FETCH NEXT FROM rs INTO ShizuName, CurrentLingQi;     
17      /* 遍历数据表 */
18      REPEAT
19            IF NOT Done THEN
20               SET CurrentLingQi = CurrentLingQi + 60;
21               /* 如果更新后灵气值大于允许的最大值，则就设置为最大值 */
22               IF CurrentLingQi >= 1800 THEN
23                  UPDATE socialrelation SET LingQi = 1800 WHERE NodeName = ShizuName;
24               ELSE
25               /* 否则，正常更新 */
26                  UPDATE socialrelation SET LingQi = LingQi + 60 WHERE NodeName = ShizuName;
27               END IF;
28            END IF;
29           
30      FETCH NEXT FROM rs INTO ShizuName, CurrentLingQi;
31 
32      UNTIL Done END REPEAT;
33     
34      /* 关闭游标 */
35      CLOSE rs;
36 END