问题描述

我将 spring-data mongo 与基于 JSON 的查询方法一起使用，但不确定如何在搜索查询中允许可选参数.

I am using spring-data mongo with the JSON based query methods, and am unsure how to allow optional parameters in a search query.

例如 - 假设我有以下功能

For instance - say I had the following function

@Query("{ 'name' : {$regex : ?0, $options : 'i'}, 'createdDate' : {$gte : ?1, $lt : ?2 }} }")
List<MyItem> getItemsLikeNameByDateRange(String name, Date startDateRange, Date endDateRange);

-但我不想应用名称正则表达式匹配，或者如果将 NULL 值传递给方法，则不应用日期范围限制.

-but I didnt want to apply the name regex match, or not apply a date range restriction if NULL values were passed to the method.

目前看来我可能必须使用 mongoTemplate 构建查询.

At the moment it looks like I might have to build the query using the mongoTemplate.

是否有任何替代方案 - 或者使用 mongoTemplate 是最佳选择?

Are there any alternatives - or is using mongoTemplate the best option?

谢谢

推荐答案

为了在布尔逻辑中实现这一点，我执行以下操作并转换为编程语言中可用的操作

To implement this in Boolean logic I do the following and the conversion to operations that are available in programming languages

:query != null -> field == :query
!(:query != null) || (field == :query)
(:query == null) || (field == :query)

在普通的 SQL 中，这是这样完成的

In plain SQL, this is done as

where (null = :query) or (field = :query)

在 MongoDB 中，这是通过 $where 完成的

In MongoDB this is done through the $where

{ $where: '?0 == null || this.field == ?0' } 

我们可以通过使用 Mongo 操作来加快速度一点，而不是以牺牲一些可读性为代价构建函数的所有内容.不幸的是，它不起作用.

We can speed this up a little by using Mongo Operations rather than building everything to the function at the expense of some readability. does not work unfortunately.

{ $or : [ { $where: '?0 == null' } , { field : ?0 } ] } 

所以你拥有的是

@Query("{ $or : [ { $where: '?0 == null' } , { field : ?0 } ] }")
List<Something> findAll(String query, Pageable pageable);

这可以进一步扩展为处理 in/all 子句的数组

This can be further expanded to handle arrays for in/all clauses

@Query("{ $or : [ { $where: '?0.length == 0' } , { field : { $in : ?0 } } ] }")
List<Something> findAll(String query, Pageable pageable);

这篇关于spring-data-mongo - 可选查询参数?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跟版网！