Grails/Hibernate:如何通过 isnull(property) 排序以最后获得 NULL? [英] Grails/Hibernate: how to order by isnull(property) to get NULLs last?

问题描述

通常在按字段升序排序时，您首先获得 NULL 值，然后是更有趣的值.通常，您希望最后使用 NULL 值.在 MySQL 中，你可以这样做:

Normally when ordering ascending by a field, you get the NULL values first, and then the more interesting values. Often, you want NULL values last. In MySQL, you can do this with:

SELECT * FROM people ORDER BY ISNULL(name), name;

但是，我使用带有 Hibernate 标准的 Grails，我完全不知道如何在那里执行此操作.这甚至以任何方式支持吗?有什么方法可以按自定义 SQL 表达式排序吗?我不想将我的所有标准重写为普通 SQL，只是为了让它正确排序.

However, I'm using Grails with Hibernate criteria, and I have absolutely no idea how to do this there. Is this even supported in any way? Is there some way to order by a custom SQL expression? I'd hate to rewrite all my criteria to plain SQL just to get it to sort correctly.

推荐答案

在休眠状态下，您可以尝试使用以下代码:

In hibernate you can try with this below code :

标准 c = ...;

Criteria c = ...;

c.addOrder(Order.asc("name").nulls(NullPrecedence.LAST));

c.addOrder(Order.asc("name").nulls(NullPrecedence.LAST));

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