oracle merge into update语法oracle merge into update语法 The syntax for the Oracle MERGE INTO UPDATE statement is as follows: ``` MERGE INTO target_table USING source_table ON (join_condition) WHEN MATCHED THEN UPDATE SET column1 = value1, column2 = value2 ... ``` Explanation: - The ...
Merge用法:Oracle 10g中对Merge语句的增强 在Oracle 10g之前,merge语句支持匹配更新和不匹配插入2种简单的用法,在10g中Oracle对merge语句做了增强,增加了条件选项和DELETE操作。下面我通过一个demo来简单介绍一下10g中merge的增强和10g前merge的用法。 参考Oracle 的SQL Reference,大家可以看到Merge Statement的语法如下:...
Use theMERGEstatement to select rows from one or more sources for update or insertion into a table or view. You can specify conditions to determine whether to update or insert into the target table or view. 使用MERGE语句选择行从一个或多个源更新或插入一个表或视图。您可以指定条件来决定是否更...
在上面例子中, MERGE语句影响到是产品id为1502, 1601和1666的行. 它们的产品名字和种 类被更新为表newproducts中的值. 下面例子省略UPDATE子句, 把表NEWPRODUCTS中新的PRODUCT_ID插入到表PRODUCTS中, 对于在两个表中能够匹配上PRODUCT_ID的数据不作任何处理. 从这个例子你能看到PRODUCT_ID=1700的行被插入到表PROD...
这时候,就需要用merge语句。通过merge语句能够避免自己手写好多if判断,程序简洁,更好维护。 merge语句的语法 MERGE INTO target_table USING source_table ON search_condition WHEN MATCHED THEN UPDATE SET col1 = value1, col2 = value2,... WHERE <update_condition> [DELETE WHERE <delete_condition>] WHEN...
3. DML: MERGE 3.1 Overview of DML Statements The five DML statements available in Oracle are INSERT, UPDATE, DELETE, MERGE and TRUNCATE. The first three are somewhatexplanatory. MERGE may not be. A MERGE statement will take one row source and merge it into another. And what that means is...
The following illustrates the syntax of the OracleMERGEstatement: MERGEINTOtarget_tableUSINGsource_tableONsearch_conditionWHENMATCHEDTHENUPDATESETcol1 = value1, col2 = value2,...WHERE<update_condition> [DELETEWHERE<delete_condition>]WHENNOTMATCHEDTHENINSERT(col1,col2,...)values(value1,value2,.....
参考Oracle 的SQL Reference,大家可以看到Merge Statement的语法如下: MERGE [hint] INTO [schema .] table [t_alias] USING [schema .] { table | view | subquery } [t_alias] ON ( condition ) WHEN MATCHED THEN merge_update_clause WHEN NOT MATCHED THEN merge_insert_clause; ...
A table lock, also called a TM lock, is acquired by a transaction when a table is modified by an INSERT, UPDATE, DELETE, MERGE, SELECT with the FOR UPDATE clause, or LOCK TABLE statement. DML operations require table locks to reserve DML access to the table on behalf of a transaction ...
SELECT、INSERT、DELETE、UPDATE、MERGE 2、数据定义语言语句 数据定义语言语句(Data definition language,DDL)用于定义数据的格式和形态,比如定义数据表、视图和索引等数据库对象。在建立数据库时用户首先要使用的就是DDL语句。 CREATE、ALTER、DROP、RENAME、TRUNCATE ...