优化update语句

Question

我目前正在尝试优化sql代码。我想知道是否有其他方法来编写这些语句，因为它似乎需要很长时间才能完成。

Update #TMP---updates  webid when its null in tmp table
Set #TMP.webid_Val='NOT COMPLIANT'
Where  #TMP.webid is null

Update #TMP---updates  PID when its null in tmp table
Set #TMP.PID_Val='NOT COMPLIANT'
Where  #TMP.Pid is null

Update #TMP---Shifts multiple fob situations into storewide
Set #TMP.GMM ='Storewide'
Where  #TMP.gmm like '%, %';

Update #TMP-----Shifts marketing into multiple fob situation
Set #TMP.GMM ='Storewide'
Where  #TMP.gmm like 'Marketing%'


Update #TMP
Set #TMP.OVERALL_Val='NOT COMPLIANT'
Where  #TMP.webid is null

这确实有超过22,000个条目。

Answer 1

不能肯定这会更快，因为它取决于数据，但单个update语句可能执行得最好。

Update #TMP
Set #TMP.webid_Val=
        CASE
            WHEN #TMP.webid is null THEN 'NOT COMPLIANT'
            ELSE #TMP.webid_Val
        END
     ,#TMP.PID_Val=
        CASE
            WHEN #TMP.Pid is null THEN 'NOT COMPLIANT'
            ELSE #TMP.PID_Val
        END
     ,#TMP.GMM=
        CASE
            WHEN (#TMP.GMM like '%, %' OR #TMP.gmm like 'Marketing%') THEN 'Storewide'
            ELSE #TMP.GMM
        END
    ,#TMP.OVERALL_Val=
        CASE
            WHEN (#TMP.webid is null) THEN 'NOT COMPLIANT'
            ELSE #TMP.OVERALL_Val
        END
WHERE #TMP.webid is null
OR #TMP.Pid is null
OR #TMP.gmm like '%, %'
OR #TMP.gmm like 'Marketing%'

Answer 2

我看到的第一个部分是，您可以组合这两个update语句：

Update #TMP---updates  webid when its null in tmp table
Set #TMP.webid_Val='NOT COMPLIANT'
Where  #TMP.webid is null

Update #TMP
Set #TMP.OVERALL_Val='NOT COMPLIANT'
Where  #TMP.webid is null

进入：

Update #TMP---updates  webid when its null in tmp table
Set #TMP.webid_Val='NOT COMPLIANT',
    #TMP.OVERALL_Val='NOT COMPLIANT'
Where  #TMP.webid is null

您可以将这两个GMM更新合并为以下内容：

Update #TMP---Shifts multiple fob situations into storewide
Set #TMP.GMM ='Storewide'
Where  LEFT(#TMP.gmm, 9) = 'Marketing'
OR #TMP.gmm like '%, %';

与LIKE匹配相比，执行LEFT应该会有更高的性能(注意:不能确定这一点，您必须对其进行测试以进行验证)。