SQL多表关联数据更新,如果数据量比较少的情况下,用Update也是可以的:脚本如下: UPDATE NA_AgentGrpOrder SET AttrServSIItem=b.AttrValue FROM NA_AgentGrpOrderAttribute b WHERE NA_AgentGrpOrder.SubsProdid=b.SubsProdid 当数量比较大时,直接用Update语句更新,效率相对会比较低,建议用Merger和Using来实现数据更新:在Merger后的是目标表,Usi
create table #ttt(id int,name nvarchar(10));merge into #ttt t using (select 1 as id ,'eee' as name ) b on (t.id = b.id) when matched then update set t.name = b.name when not matched then insert(id,name) values(b.id,b.name); select * from #ttt; merge
版权声明:本文为CSDN博主「暮雪寒寒」的原创文章,遵循 CC 4.0 BY-SA 版权协议,转载请附上原文出处链接及本声明.原文链接:https://blog.csdn.net/qq_27628011/article/details/89319710 MERGE tABatch AS t -- 需要操作的主体表 USING( ) AS waitTotal FROM ( SELECT batchNo FROM OPENJSON(@checkJson) ) '$.batchNo') ) t GRO
merge集插入,更新,删除于一体,如果要对一个表同时进行插入,更新,删除2个或3三个操作.效率要高于单个操作. merge into tableb b --被操作表using (select id,servicepromotor,servicecmclient from tablea where servicepromotor>0) a--参照表 支持子查询on a.id=b.client --关联关系when matched --a,b表均匹配到做updatethen update set
Key words: merge compare columns when we contact merge sql in ETL, When we update some columns we should compare the value change or not. We always write coalesce(columnname,valueifnull)<>coalesce(columnname,valueifnull) But we should take care of t
题意: Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists. (Easy) 分析: 链表题,注意细节即可. 链表merge和数组merge的不同在于链表不用拷一份出来,倒腾一下指针就可以啦. 注意事项有: 1. dummy node用于输出,head(或者换个名字)用于