As MERGE statement in SQL, as discussed before in theprevious post, is the combination of threeINSERT,DELETEandUPDATEstatements. So if there is aSource tableand aTarget tablethat are to be merged, then with the help of MERGE statement, all the three operations (INSERT, UPDATE, DELETE) can ...
Using the MERGE statement in SQL gives you better flexibility in customizing your complex SQL scripts and also enhances the readability of your scripts. The MERGE statement basically modifies an existing table based on the result of comparison between the key fields with another table in the context...
在MERGE NOT MATCHED 操作中,只允许执行 INSERT 语句。 一个MERGE语句中出现的MATCHED操作,只能出现一次 UPDATE 或者 DELETE 语句,否则就会出现下面的错误:An action of type 'WHEN MATCHED' cannot appear more than once in a 'UPDATE' clause of a MERGE statement. MERGE示例 下面我们通过一个示例来介绍一下...
在MERGE NOT MATCHED 操作中,只允许执行 INSERT 语句。 一个MERGE语句中出现的MATCHED操作,只能出现一次 UPDATE 或者 DELETE 语句,否则就会出现下面的错误: An action of type 'WHEN MATCHED' cannot appear more than once in a 'UPDATE' clause of a MERGE statement. MERGE示例 下面我们通过一个示例来介绍一下...
You may receive the following error message when you run a MERGE statement in Microsoft SQL Server 2008: Msg 8672, Level 16, State 1, Line 1 The MERGE statement attempted to UPDATE or DELETE the same row more than once. This happens when ...
一个MERGE语句中出现的MATCHED操作,只能出现一次 UPDATE 或者 DELETE 语句,否则就会出现下面的错误:An action of type 'WHEN MATCHED' cannot appear more than once in a 'UPDATE' clause of a MERGE statement. MERGE示例 下面我们通过一个示例来介绍一下该如何使用MERGE,我们以Custo...
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, updating, or deleting rows in one table based on differences found in the other...
SQL CREATEPROCEDUREdbo.InsertUnitMeasure @UnitMeasureCodeNCHAR(3), @NameNVARCHAR(25)ASBEGINSETNOCOUNTON;-- Update the row if it exists.UPDATEProduction.UnitMeasureSETName= @NameWHEREUnitMeasureCode = @UnitMeasureCode-- Insert the row if the UPDATE statement failed.IF(@@ROWCOUNT =0)BEGININSERTI...
SQL CREATEPROCEDUREdbo.InsertUnitMeasure @UnitMeasureCodeNCHAR(3), @NameNVARCHAR(25)ASBEGINSETNOCOUNTON;-- Update the row if it exists.UPDATEProduction.UnitMeasureSETName= @NameWHEREUnitMeasureCode = @UnitMeasureCode-- Insert the row if the UPDATE statement failed.IF(@@ROWCOUNT =0)BEGININSERTI...
Merge语句是一种用于数据库操作的SQL语句,用于将源表的数据合并(插入、更新或删除)到目标表中。它可以根据指定的条件判断源表中的数据是否已存在于目标表中,如果存在则执行更新操作,如果不存在则执行插入操作。 Merge语句的优化可以提高数据库操作的效率和性能,以下是一些优化技巧: ...