Oracle 11g:Scalar Subquery expression Limitation

最新推荐文章于 2024-06-14 09:43:18 发布

最新推荐文章于 2024-06-14 09:43:18 发布 · 240 阅读

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#数据库

本文详细阐述了在SQL中哪些位置不允许使用标量子查询，包括默认值、集群哈希表达式、DML语句的RETURNING子句、基于函数的索引、CHECK约束、GROUP BY子句以及与查询无关的语句。

Scalar subqueries are not valid expressions in the following places:
 
- As default values for columns
- As hash expressions for clusters
- In the RETURNING clause of DML statements
- As the basis of a function-based index
- In CHECK constraints
- In GROUP BY clauses
- In statements that are unrelated to queries, such as CREATE PROFILE

Reference:http://docs.oracle.com/cd/B28359_01/server.111/b28286/expressions013.htm