oracle 10g里，Merge语句的重大改进 zt

发表人:www.wwf.co | 发表时间: 2007年七月23日, 10:10

1, 能嵌入delete语句

2, update, insert语句能嵌入where clause

3, update语句与insert语句，不必同时出现，是可选的（optional）

http://www.oracle-base.com/articles/10g/MergeEnhancements10g.php

MERGE Statement Enhancements in Oracle Database 10g

Oracle 10g includes a number of amendments to the MERGE statement making it more flexible.

• Test Table
• Optional Clauses
• Conditional Operations
• DELETE Clause

Test Table

The following examples use the table defined below.

Optional Clauses

The MATCHED and NOT MATCHED clauses are now optional making all of the following examples valid.

Conditional Operations

Conditional inserts and updates are now possible by using a WHERE clause on these statements.

DELETE Clause

An optional DELETE WHERE clause can be used to clean up after a merge operation. Only those rows which match both the ON clause and the DELETE WHERE clause are deleted.

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