MySQL 存儲過程裏使用遊標

#定義存儲過程，並命名爲proc_traceLog 
1 BEGIN
 2 #聲明臨時變量
 3 DECLARE planNo VARCHAR(32);
 4 DECLARE trainNo VARCHAR(32);
 5 DECLARE content VARCHAR(255);
 6 DECLARE done int DEFAULT 0 ;
 7 
 8 DECLARE cur_train CURSOR FOR 
 9     SELECT p.plan_no,p.train_no,g.operate_content
10       FROM nature_order_plan p LEFT JOIN 
11                 (SELECT c.`no`,c.operate_content 
12                    FROM common_log c JOIN( SELECT `no`,MAX(id) id FROM common_log GROUP BY `no`) l ON c.id = l.id
13                 )g ON p.plan_no = g.`no`
14      WHERE p.`status` = 40
15        AND p.transport_way = '鐵運門到站';
16 
17 #設置循環結束標誌
18 DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;
19 
20 #若是臨時表已存在，刪除臨時表
21 DROP TABLE IF EXISTS tmpTable;
22 
23 #建立臨時表
24 CREATE TABLE tmpTable
25 (
26 plan_no VARCHAR(32),
27 train_no VARCHAR(32),
28 cabinet_no VARCHAR(32),
29 operate_content VARCHAR(255)
30 );
31 
32 #打開遊標
33 OPEN cur_train;
34 
35 #遍歷遊標
36 REPEAT
37     FETCH cur_train INTO planNo,trainNo,content;
38     IF NOT done THEN
39         #有火車號,則將計劃單號、火車號、最新日誌插入到臨時表
40         IF trainNo THEN 
41             INSERT INTO tmpTable(plan_no,train_no,operate_content) VALUES(planNo,trainNo,content);
42         #不然插入計劃單號、集裝箱號、對應的最新日誌到臨時表
43       　ELSE
44             INSERT INTO tmpTable(plan_no,cabinet_no,operate_content)
45             SELECT p.plan_no,c.cabinet_no,l.operate_content
46                 FROM nature_order_plan p JOIN nature_order_plan_cabinet c ON p.plan_no = c.plan_no
47                          LEFT JOIN(SELECT a.`no` AS plan_no,b.canbinet_no,a.operate_content
48                                      FROM common_log a JOIN( SELECT `no` AS plan_no,SUBSTR(operate_content FROM 5 FOR 11) AS canbinet_no,MAX(id) AS id
49                                                                FROM common_log
50                                                               WHERE source = '12306'
51                                                                 AND module = 2
52                                                                 AND type = 0
53                                                                 AND `no` = planNo
54                                                               GROUP BY SUBSTR(operate_content FROM 5 FOR 11)
55                                                              ) b ON a.id = b.id
56                                    )l ON c.plan_no = l.plan_no AND c.cabinet_no = l.canbinet_no 
57              WHERE p.plan_no = planNo;
58         END IF;
59     END IF;
60 UNTIL done 
61 END REPEAT; #循環結束
62 CLOSE cur_train;
63 END

注意：MySQL定義遊標以前不能定義別的操做語句，因此把定義表放在了定義遊標的後面

python3調用存儲過程以下：

import pymysql.cursors

class CrawlDao():
    def __init__(self):
        self.connect = pymysql.connect(host=getDBHost(), port=getDBPort(), user=getDBUsername(),
                                       passwd=getDBPassword(),
                                       db=getDBDatabase(), charset=getDBCharset())
        self.cursors = self.connect.cursor()
        self.logger = Logger('CrawlDao').getLogger()

    def selectPlanOrderLog(self):
        '''
        調用存儲過程proc_traceLog，將狀態爲服務中，運輸方式爲鐵運的計劃單插入到tmpTable表中
        tmpTable表數據分爲2部分，一部分是火車號train_no不爲空，則不查詢集裝箱號cabinet_no，最新日誌取最新一條
        第二部分是火車號train_no爲空，查詢集裝箱號及對應的最新日誌（截取操做日誌取集裝箱號進行關聯）
        :return:計劃單號、火車號、集裝箱號、最新操做日誌
        '''

　　　　　#調用存儲過程
        self.cursors.callproc('proc_traceLog')
        cmd = 'SELECT plan_no,train_no,cabinet_no,operate_content FROM tmpTable;'
        try:
            self.cursors.execute(cmd)
            result_tuple = self.cursors.fetchall()
            return result_tuple  # 返回數據類型爲元祖
        except Exception as e:
            self.logger("查詢計劃單失敗：%s" % e)
        finally:
            self.cursors.close()
            self.connect.close()