本文介绍了SQL Server 是否支持 IS DISTINCT FROM 子句?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
SQL Server 是否支持 SQL:1999 标准的 IS DISTINCT FROM
语句?例如.查询
Does SQL Server support IS DISTINCT FROM
statement which is SQL:1999 standard? E.g. the query
SELECT * FROM Bugs WHERE assigned_to IS NULL OR assigned_to <> 1;
可以使用 IS DISTINCT FROM
SELECT * FROM Bugs WHERE assigned_to IS DISTINCT FROM 1;
推荐答案
不,它没有.以下 SO 问题解释了如何将它们重写为等效(但更详细)的 SQL Server 表达式:
No, it doesn't. The following SO question explains how to rewrite them into equivalent (but more verbose) SQL Server expressions:
- 如何重写IS DISTINCT FROM和IS NOT DISTINCT FROM?
还有一个针对此问题的 Uservoice 条目,您可以在其中投票支持将其纳入下一版本:
There's also a Uservoice entry for this issue, where you can vote for inclusion in the next release:
- 添加对 ISO <distinct predicate> 的语言和优化器支持
- Add language and optimizer support for ISO <distinct predicate>
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