NSPredicate表达式中SUBQUERY的快速说明 [英] Quick Explanation of SUBQUERY in NSPredicate Expression

问题描述

似乎有关于SUBQUERY关键字从零的文档，我没有找到一个简单的解释它在SO或在谷歌。这是一个阴谋！ ;）

There appears to be zero documentation about the SUBQUERY keyword from Apple and I can't find a simple explanation about it on SO or on Google. It's a conspiracy! ;)

，内圈的某人可以快速解释其语法， p>

Please, could someone from the inner-circle please just provide a quick explanation of its syntax so I can use it?

SUBQUERY(Bs, $x, $x IN %@)

感谢

推荐答案

这是一个子查询求值为。（从这个邮件列表线程，Google中的NSPredicate子查询的＃1命中。）这一点文档还解释了谓词格式字符串语法如何与之相关。

This is what a subquery evaluates to. (Found from this mailing list thread, the #1 hit for "NSPredicate subquery" in Google.) That bit of documentation also explains how the predicate format string syntax relates to it.

这篇关于NSPredicate表达式中SUBQUERY的快速说明的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！