INSERT ... --When there is a row that exists in target table and --same record does not exist in source table --then delete this record from target table [WHEN NOT MATCHED BY SOURCE THEN ]; DELETE OUTPUT $action, DELETED.CodeID AS TargetCodeID, DELETED.TaxCode AS TargetTaxCode, DELE...
INSERT INTO TargetTable(id,[desc]) VALUES(2,'在源表存在,将会被更新') INSERT INTO TargetTable(id,[desc]) VALUES(5,'在源表不存在,将会被删除') INSERT INTO TargetTable(id,[desc]) VALUES(6,'在源表存在,将会被删除') SELECT*fromTargetTable SELECT*fromSourceTable MERGE INTO TargetTable AS ...
SQL MERGE语句是在SQL Server 2008版中引入的,它为数据库程序员提供了极大的灵活性,可以简化他们在INSERT,UPDATE和DELETE语句周围的混乱代码,同时应用在ETL中实现SCD的逻辑。 (Optimizing the performance of the SQL MERGE statement) There are a few aspects using which you can optimize the performance of your...
如果有两个 WHEN MATCHED 子句,一个必须指定 UPDATE 操作,另一个必须指定 DELETE 操作。 如果在<merge_matched>子句中指定了 UPDATE,并且根据<merge_search_condition>中有多行与target_table中的一行匹配, SQL Server 便会返回错误。 MERGE 语句无法多次更新同一行,也无法更新和删除同一行。 WHEN NOT MATCHED...
以下是实现SQL Server MERGE INTO优化的过程: 每一步的详细说明 1. 确定目标和源表结构 在进行MERGE操作之前,首先需要明确源表和目标表的结构,包括数据类型、约束条件及索引。这将为后续的操作奠定基础。 例如,假设我们有两个表: TargetTable:需要更新或插入数据的目标表。
Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse AnalyticsThe MERGE statement runs insert, update, or delete operations on a target table from the results of a join with a source table. For example, synchronize two tables by inserting, updating, or deleting ...
15target.ModifiedDate=GETDATE() 16OUTPUT $action, Inserted.ProductID, Inserted.Quantity, Inserted.ModifiedDate, Deleted.ProductID, 17Deleted.Quantity, Deleted.ModifiedDate; 18GO 这个语句比第一个要复杂一点,注意当匹配成功并且总量小于0的时候直接使用一个delete就可以将此条记录删除,output语句直接把操作结果...
WHEN NOT MATCHED BY TARGET THEN INSERT (CustomerID, ProductID, LastPurchaseDate) VALUES (Source.CustomerID, Source.ProductID, Source.PurchaseDate) OUTPUT $action, Inserted.*, Deleted.*; B. 使用 MERGE 在单个语句中对表执行 UPDATE 和 DELETE 操作 ...
SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics SQL database in Microsoft Fabric The MERGE statement runs insert, update, or delete operations on a target table from the results of a join with a source table. For example, synchronize two tables by inserting, up...
如果有两个 WHEN MATCHED 子句,一个必须指定 UPDATE 操作,另一个必须指定 DELETE 操作。 如果在<merge_matched>子句中指定了 UPDATE,并且根据<merge_search_condition>中有多行与target_table中的一行匹配, SQL Server 便会返回错误。 MERGE 语句无法多次更新同一行,也无法更新和删除同一行。 WHEN NOT MATCHED...