今天寫一個mysql存儲過程,根據自己的需求要遍歷一個數據表,因為對存儲過程用的不多,語法不甚熟悉,加之存儲過程沒有調試環境,花了不少時間才慢慢弄好,故留個痕跡。
1 BEGIN
2 DECLARE Done INT DEFAULT 0;
3
4 DECLARE CurrentLingQi INT;
5
6 DECLARE ShizuName VARCHAR(30);
7 /* 聲明游標 */
8 DECLARE rs CURSOR FOR SELECT NodeName, LingQi FROM socialrelation;
9 /* 異常處理 */
10 DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET Done = 1;
11
12 /* 打開游標 */
13 OPEN rs;
14
15 /* 逐個取出當前記錄LingQi字段的值,需要進行最大值的判斷 */
16 FETCH NEXT FROM rs INTO ShizuName, CurrentLingQi;
17 /* 遍歷數據表 */
18 REPEAT
19 IF NOT Done THEN
20 SET CurrentLingQi = CurrentLingQi + 60;
21 /* 如果更新后靈氣值大于允許的最大值,則就設置為最大值 */
22 IF CurrentLingQi >= 1800 THEN
23 UPDATE socialrelation SET LingQi = 1800 WHERE NodeName = ShizuName;
24 ELSE
25 /* 否則,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 /* 關閉游標 */
35 CLOSE rs;
36 END