Prerequisite –INSERT,UPDATE,DELETE TheMERGEcommand in SQL is actually a combination of three SQL statements:INSERT, UPDATE and DELETE. In simple words, the MERGE statement in SQL provides a convenient way to perform all these three operations together which can be very helpful when it comes to ...
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Customers表和Orders表为例。数据...
3.2 MERGE statement overview When using the merge statement, remember that you can have all three primary DML statements, insert, update and delete. One table as the source where new or updated rows are provided along with the relevant columns, or, you can have deleted rows too by specifying...
MERGE Statement Enhancements in Oracle Database 10g Oracle 10g includes a number of amendments to theMERGEstatement making it more flexible. Test Table Optional Clauses Conditional Operations DELETE Clause Related articles. MERGE Statement Test Table The following examples use the table defined below. C...
会话控制语句(Session Control Statement)用于动态修改当前用户会话的属性,在应用开发层面极少用到。 ALTER SESSION、SET ROLE 二、SQL基础 1、删除表中数据 使用DELET指令,可删除数据表中已有的数据,例如: DELETE student; 或: DELETE FROM student; 这是"DELETE"指令的最基本形式,此操作会删除student表中的所有数据...
oracle的merge sql语句Oracle的MERGE SQL语句 Oracle的MERGE语句是用于同时执行INSERT和UPDATE操作,根据指定的条件决定是插入新记录还是更新已存在的记录。下面是一个基本的MERGE语句模板: MERGE INTO target_table USING source_table ON (join_condition) WHEN MATCHED THEN UPDATE SET column1 = value1, column2 = ...
会话控制语句(Session Control Statement)用于动态修改当前用户会话的属性,在应用开发层面极少用到。 ALTER SESSION、SET ROLE 二、SQL基础 1、删除表中数据 使用DELET指令,可删除数据表中已有的数据,例如: DELETE student; 或: DELETE FROM student; 这是"DELETE"指令的最基本形式,此操作会删除student表中的所有数据...
作为SQL语句中的一种,MERGE合并可以在SQL Server以及Oracle数据库中使用。作为SQL语言中非常重要且强大的一种语句,MERGE合并语句具有广泛的应用场景。今天我们将深入介绍MERGE合并定义、语法、用法及示例。 MERGE的定义 MERGE关键字是一个神奇的DML关键字,它能将INSERT,UPDATE,DELETE等操作并为一句,根据与源表联接的结果...
简介:2015-05-21 Created By BaoXinjian 一、摘要 以前只考虑 merge into 只是在特定场合下方便才使用的,今天才发现,merge into 竟然会比 update 在更新数据时有这么大的改进。 2015-05-21 Created By BaoXinjian 一、摘要 以前只考虑 merge into 只是在特定场合下方便才使用的,今天才发现,merge into 竟然会比...
SQL statements are the means by which programs and users access data in an Oracle database. The sections that follow show each SQL statement and its related syntax. Refer toSubclausesfor the syntax of the subclauses listed in the syntax for the statements. ...