在此選擇喜歡的總和（）

在下表中，我試圖用其總票數的總和更新每一行父母。在此選擇喜歡的總和（）

這裏的一切都很好，除了我想用type = 10中的一個SUM()做事情，而不是我現在這樣做。現在，發生的情況是：如果type = 10的總數發生變化，那麼父母的總數不會調整，而是會相加。我無法弄清楚如何在那裏添加sum()。我來了這麼遠。你能幫我嗎？

如果你檢查我的存儲過程，你會看到它是如何工作的。

下面的東西很好。我不確定如何在sqlfiddle上設置存儲過程來演示它。

我叫表與likesd期望的結果

這些結果是由存儲過程以下

"id" "type" "path"   "likes" 
"1"  "1"  "0"    "20" 
"2"  "1"  "0"    "20" 
"3"  "2"  "1,2"   "20" 
"4"  "2"  "1,2,3"   "20" 
"5"  "2"  "1,2,3"   "0" 
"6"  "3"  "1,2,3,4"  "0" 
"7"  "3"  "1,2,3,4"  "0" 
"8"  "4"  "1,2,3,4"  "20" 
"9"  "10" "1,2,3,4,8"  "5" // These type 10 are books 
"10" "10" "1,2,3,4,8"  "5" // These type 10 are books 
"11" "10" "1,2,3,4,8"  "5" // These type 10 are books 
"12" "10" "1,2,3,4,8"  "5" // These type 10 are books

究竟做了這是存儲過程我使用

BEGIN 
#---- Updater for like totals 21-11-2013 

    # Declare variables 
    DECLARE procId, procLikes INT(10); 
    DECLARE procPath VARCHAR(50); 
    DECLARE done INT DEFAULT 0; 

    # Declare cursor 
    DECLARE cur1 CURSOR FOR SELECT id, path, likes FROM testLikes WHERE type = 10; 

    # Declare Handle 
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1; 

    # Open Cursor 
    OPEN cur1; 

    # Begin the Loop 
    the_loop: LOOP 

    FETCH cur1 INTO procId, procPath, procLikes; 

    IF done THEN 
    LEAVE the_loop; 
    END IF; 

    # Do some post processing 
    UPDATE testLikes t1 JOIN testLikes t2 ON FIND_IN_SET(t1.id, t2.path) 
     SET t1.likes = t1.likes + procLikes // Trying to add a sum(of all type = 10) here. 
      // Problem here is, New totals should be sum of all type = 10, but right now, it all adds up. 
      WHERE t2.id = procId; 

    END LOOP the_loop; 

    # Dummy select for MySql's bug 
    SELECT id INTO procId FROM testLikes where id = 1; 

    CLOSE cur1; 

END

來源

2013-11-22 jmenezes

數據庫規範化的原則之一是不存儲計算值。 –

與您的評論相關 - 「如何在sqlfiddle上設置存儲過程來演示它。」檢查這個在SqlFiddle上執行觸發器存儲過程。 Mysql http://stackoverflow.com/questions/12166380/execute-triggers-stored-procedures-on-sqlfiddle-mysql – Damodaran

我並不完全相信，如果這是有效的，但：

select 
type 
,SUM(likes) as NUmberofLikes 
into temp1 
from testLikes 
group by type 

UPDATE testlikes t1 
SET likes= (select NumberOFLikes from temp1 t2 where t1.type=t2.type)

來源

2013-11-22 12:54:45

在此選擇喜歡的總和（）

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