CouchDB是否支持多个范围查询？ [英] Does CouchDB support multiple range queries?

问题描述

如何在CouchDB中实现多个范围查询？对于单范围条件，startkey和endkey组合可以正常工作，但同一情况不适用于多范围条件。

How are multiple range queries implemented in CouchDB? For a single range condition, startkey and endkey combination works fine, but the same thing is not working with a multiple range condition.

我的视图函数如下：

"function(doc){
       if ((doc['couchrest-type'] == 'Item') 
    && doc['loan_name']&& doc['loan_period']&&    
                      doc['loan_amount']) 
     {  emit([doc['template_id'],
          doc['loan_name'],doc['loan_period'],
           doc['loan_amount']],null);}}"

我需要使用 loan_period > 5和
<$ c来获取整个文档$ c> loan_amount >30000。我的startkey和endkey参数如下：

I need to get the whole docs with loan_period > 5 and loan_amount > 30000. My startkey and endkey parameters are like this:

params = {:startkey =>["7446567e45dc5155353736cb3d6041c0",nil,5,30000],
  :endkey=>["7446567e45dc5155353736cb3d6041c0",{},{},{}],:include_docs => true}  

在这里，我没有得到想要的结果。我认为我的startkey和endkey参数是错误的。有人可以帮我吗？

Here, I am not getting the desired result. I think my startkey and endkey params are wrong. Can anyone help me?

推荐答案

CouchDB视图是条目的有序列表。视图上的查询返回该列表的连续切片。因此，不可能应用两个不等式条件。

A CouchDB view is an ordered list of entries. Queries on a view return a contiguous slice of that list. As such, it's not possible to apply two inequality conditions.

假设您的loan_period是一个离散变量，则最好先发出bloat_period来解决这种情况然后每个时期发出一个查询。

Assuming that your loan_period is a discrete variable, this case would probably be best solved by emit'ing the loan_period first and then issuing one query for each period.

另一种解决方案是使用ouchdb-lucene。

An alternative solution would be to use couchdb-lucene.

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