sql MERGE --WHEN NOT MATCHED BY Source 和WHEN NOT MATCHED BY TARGET 是固定格式--用USING中查到的数据S 对T表来操作MERGEINTO[Admin]T USING Admin2ASSON( T.LoginId=S.LoId )WHENNOTMATCHEDBYTARGETTHEN--目标表(T)中不存在 源表(S)中存在INSERT(LoginId ,LoginPwd )VALUES(s.loid ,s.lopwd);g...
即关联条件成功 (这时就应该将 SOURCE 中其它的所有字段值更新到 TARGET 表中)--WHEN NOTMATCHED BY TARGET - 如果匹配不成功 (TARGET 中没有这一条记录但是 SOURCE 表有,说明 SOURCE 表多了新数据因此应该插入到 TARGET 表中)--WHEN NOTMATCHED BY SOURCE - 如果匹配...
USING (SELECT CustomerID, ProductID, PurchaseDate FROM dbo.Purchases) AS Source ON (Target.ProductID = Source.ProductID AND Target.CustomerID = Source.CustomerID) WHEN MATCHED THEN UPDATE SET Target.LastPurchaseDate = Source.PurchaseDate WHEN NOT MATCHED BY TARGET THEN INSERT (CustomerID, Produc...
WHEN NOT MATCHED BY SOURCE THEN DELETE; 最后就是源表中存在,但是目标表中不存在的情况了,我们只需要将上面的BY SOURCE改成BY TARGET即可,通过下面这条语句我们将把源表与目标表不匹配的数据添加到目标表中去(当然我们需要提前在源表中新增一条数据): WHEN NOT MATCHED BY TARGET THEN INSERT (Name) VALUES...
WHEN NOT MATCHED BY SOURCE THEN <merge_matched> 指定根据<merge_matched>子句更新或删除 *target_table 中所有与<table_source>ON<merge_search_condition>返回的行不匹配而满足其他所有搜索条件的行。 MERGE 语句最多可以有两个 WHEN NOT MATCHED BY SOURCE 子句。 如果指定了两个子句,第一个子句必须随附 AND...
test_from.val) -- 源表有，目标表没有，插入WHEN NOT MATCHED BY SOURCE THEN DELETE; -- 目标表有，源表没有，目标表该数据删除.-- 再次检查 目标表数据.SELECT * FROM test_to;id val--- --- 1 A2 3 C这样的一个 例子 + 带有注释的 SQL 语句， 能理解了么？使用 ME...
[ AND <clause_search_condition> ] THEN <merge_matched> ] [ ...n ] [ WHEN NOT MATCHED [ BY TARGET ] [ AND <clause_search_condition> ] THEN <merge_not_matched> ] [ WHEN NOT MATCHED BY SOURCE [ AND <clause_search_condition> ] THEN <merge_matched> ] [ ...n ] [ <output_...
WHEN NOT MATCHED THEN INSERT(Custid,CompanyName) VALUES(CS.Custid,CS.CompanyName) -- 目标表中的数据不被源表匹配 WHEN NOT MATCHED BY SOURCE THEN DELETE; 以上各个分支子句,如:WHEN MATCHED THEN可以附带额外的判断条件,即WHEN MATCHED AND... THEN。详细内容,可参考MERGE (Transact-SQL)。
WHEN NOT MATCHED THEN INSERT:当目标表和源表不匹配时,指定要执行的插入操作。可以提供要插入的值,可以是源表中的列值或常量。 WHEN NOT MATCHED BY SOURCE THEN DELETE:可选子句,用于在源表中没有匹配时执行删除操作。 MERGE语句的执行过程如下:
WHEN NOT MATCHED BY SOURCE [ ANDnot_matched_by_source_condition] 适用于: Databricks SQL Databricks Runtime 12.2 LTS 及更高版本 当目标行与源表中的任何行都不匹配(根据WHEN NOT MATCHED BY SOURCE进行匹配)并且可选的merge_condition计算为 true 时,将执行not_match_by_source_condition子句。