如何创建具有可变日期的部分索引? [英] How to create a partial index with variable date?

问题描述

我想在MongoDB中创建部分索引，该索引不包括从当前日期算起过去30天的文档.

I want to create a partial index in MongoDB which excludes documents that are older than 30 days in the past from the current date.

类似这样的东西(伪代码):

Something like this (pseudo code):

partialFilterExpression: { date: { $gte: { $currentDate - 30 days }} }

$currentDate应该是实际的当前日期，换句话说，日期是一个动态值，而不是静态值.

The $currentDate should be the actual current date, in other words the date is a dynamic value, not a static value.

有可能吗?

推荐答案

据我所知，部分索引&当前不支持过滤器表达式中的动态值.过滤器表达式仅支持常规mongo查询运算符的子集(并且该子集不包含$date运算符).

As far as I know, dynamic values in the filter expression are not currently supported with partial indexes & the filter expression only supports a subset of regular mongo query operators (and that subset does not include the $date operator).

一种近似所需行为的方法是在文档上创建一个shouldIndex布尔字段，将{shouldIndex: true}作为您的过滤器表达式，并针对每天早于.

One way to approximate your desired behavior is by creating a shouldIndex boolean field on your documents, have {shouldIndex: true} be your filter expression, and have a script update that field once a day for documents that are older than current_date - 30.

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