Question

我有一个数据库，它是从一个实用程序中填充的，它不能很好地处理同时请求。

在这些表中插入行的逻辑是有缺陷的，这允许派生表中的重复。我的目标是修复那些重复。

有两种类型的重复项：

如果密钥是重复的，但我们可以使用数字来告诉他们开
Key和Number都是重复的，在这种情况下我想要更新第一次出现。

情况如何出现

#history_table{
  display:block;
  position:relative;

  background-color:#CCCCCC;
  border:2px solid black;
  margin-left: initial;
  /*width:9px;*/

  width:100%;

 table-layout: fixed; /* Include this code */


}

#history_table td{  
  display:block;
}

这导致以下表格：

基

/** Sequence of events **/


/** First Set (Correct) **/

Insert into Base values(100,'Base1');
    /** Find the biggest IKey in Base Table **/
    /** Set that as IKey in Derived Table (IKey = 1)**/
Insert into Derived values(1,100,'Derived1');

Insert into Base values(101,'Base2');
    /** Find the biggest IKey in Base Table **/
    /** Set that as IKey in Derived Table (IKey = 2)**/
Insert into Derived values(2,101,'Derived2');



/** Second Set ( duplicate IKey )**/

Insert into Base values(200,'Base3');
    /** Find the biggest IKey in Base Table **/
    /** We would have gotten 3, but there was another insert before this query could be run **/
Insert into Base values(201,'Base4');
    /** Because of the insert, we got a 4 instead of a 3 **/


    /** Set that as IKey in Derived Table (IKey = 4)**/
Insert into Derived values(4,200,'Derived3');
    /** Find the biggest IKey in Base Table **/
    /** Set that as IKey in Derived Table (IKey = 4)**/
Insert into Derived values(4,201,'Derived4');




/** Third Set ( duplicate IKey and Number )**/

Insert into Base values(300,'Base5');
    /** Find the biggest IKey in Base Table **/
    /** We would have gotten 5, but there was another insert before this query could be run **/
    /** This even had the "Number" column same as previous insert **/ 

Insert into Base values(300,'Base6');
    /** Because of the insert, we got a 6 instead of a 5 **/
    /** Set that as IKey in Derived Table (IKey = 6)**/

Insert into Derived values(6,300,'Derived5');
    /** Find the biggest IKey in Base Table **/
    /** Set that as IKey in Derived Table (IKey = 6)**/
Insert into Derived values(6,300,'Derived6');

派生

IKey Number Base
1   100     Base1
2   101     Base2
3   200     Base3
4   201     Base4
5   300     Base5
6   300     Base6

我已经能够找到案例＃1的解决方案。

IKey Number Derived
1   100     Derived1
2   101     Derived2
4   200     Derived3
4   201     Derived4
6   300     Derived5
6   300     Derived6

我想找到＃2的解决方案。

这是一个用于试验问题的工作空间。 http://sqlfiddle.com/#!3/e5f4e/4

SQL Update首次出现重复

0 个答案: