Now that we have learned how to insert records using the SQL MERGE statement, let us learn how to update the values in the same statement. In order to update the values, the ProductID field must have a common value in both the source and the target tables. Only then the database engin...
在SQL Server 2008 中,您可以使用 MERGE 语句在一条语句中执行插入、更新或删除操作。MERGE 语句允许您将数据源与目标表或视图联接,然后根据该联接的结果对目标执行多项操作。例如,您可以使用 MERGE 语句执行以下操作: 有条件地在目标表中插入或更新行。
AND soh.OrderDate = @OrderDate GROUP BY ProductID) AS source (ProductID, OrderQty) ON (target.ProductID = source.ProductID) WHEN MATCHED AND target.Quantity - source.OrderQty <= 0 THEN DELETE WHEN MATCHED THEN UPDATE SET target.Quantity = target.Quantity - source.OrderQty, target....
Server. TheMERGEstatement in SQL is a very popular clause that can handle inserts, updates, and deletes all in a single transaction without having to write separate logic for each of these. You can specify conditions on which you expect the MERGE statement to insert, update, or delete, etc...
数据操纵语言,Data manipulation language,检称DML,主要包括检索(SELECT)、插入(INSERT)、更新(UPDATE)、删除(DELETE),是SQL的一个核心部分。一条DML将开始一个事务,接下来的DML都是同一事务中的语句,直到提交(COMMIT)或回滚(ROLLBACK)。下面我们来逐一介绍下ORACLE中的插入、更新、删除和合并(MERGE)的语法及实例解析...
merge mytable as T using(SELECT '123' as a) N on (T.a != N.a) and T.id=2 when matched thenupdate set T.a=N.a 试试这个
sql server merge into 与update 批量更新1 百万测试数据的性能比较 1. 1百万的测试数据的生成 declare @index int; begin set @index=0; while @index<1000000 begin insert into teptable values(@index,STR(@index)+'name',str(@index)+'appname'); ...
In SQL Server 2008, you can perform insert, update, or delete operations in a single statement using the MERGE statement. The MERGE statement allows you to join a data source with a target table or view, and then perform multiple actions against the target based on the results of that ...
在SQL Server 2008 中,通过使用 MERGE 语句,可以在单个语句中执行多个数据操作语言 (DML) 操作。例如,您可能需要根据在另一个表中找到的差异在一个表中插入、更新或删除行,从而对两个表进行同步。通常,可以通过执行包含各个 INSERT、UPDATE 和 DELETE 语句的存储过程或批处理来实现这一目的。然而,这意味着需要多次...