couchdb 搜索或过滤键数组 [英] couchdb search or filtering on key array

问题描述

我的视图函数中有这个:

I have this in my view function:

emit([doc.address.country,doc.address.state, doc.address.city], doc);

当我查询搜索时，需要把数组的3个元素都填满，例如:

When I query the search, I need to have all 3 elements of the array filled in, for example:

?key=["US","NY","New York"]

这将生成我的记录，但例如，我只想返回美国的所有内容，例如:

that will produce my records, but lets say for example, I just want to return everything in the US for example:

?key=["US"]   

或者在美国和州...

or in the US and State...

?key=["US","NY"] 

或者...可以说也许我只想要来自纽约的所有记录...(我知道以下不起作用)

OR... lets say perhaps I want just all records from NY... (i know the below doesn't work)

?key=["","NY"]

如果您想将数组的元素之一留空，我真的不知道如何搜索?

I don't really get how to search if you want to leave one of the elements of the array empty?

推荐答案

第一:

key=["US"] 对数组键 ["US","NY"] 不起作用，因为您正在寻找精确 ["US"] 的键.相反，你必须使用

key=["US"] will not work on an Array Key ["US","NY"], cause you're looking for a key that is EXACT ["US"]. Instead, you have to use

startkey=["US"]&endkey=["US",{}] 

然后这些键在结果集中:

then those Keys are in the resultset:

["DE","Bavaria","Munich"]   <---- NO ! "DE" is out of Range of startkey
["US","FL","Miami"]         <---- YES, starts with "US"
["US","NY","New York"]      <---- YES, starts with "US"
["VE","XX","Vencuela City"] <---- NO ! "VE" is out of Range of endkey

也在工作:

startkey=["US","FL"]&endkey=["US","FL",{}] 

结果:

["DE","Bavaria","Munich"]   <---- NO ! "DE" is out of Range of startkey
["US","FL","Miami"]         <---- YES, starts with "US","FL"
["US","NY","New York"]      <---- NO, "US","NY" is out of Range of endkey
["VE","XX","Vencuela City"] <---- NO ! "VE" is out of Range of endkey

第二:你不能在左边有空格..所以你必须写更多的发射:(如果不需要查询，则不必发出第二个和第三个数组项)

Second: You cannot have blanks on left side.. so you have to write some more emits: ( you do not have to emit the second and third array-item, if you do not need to query it)

查看byStateCityCountry":

view "byStateCityCountry":

emit([doc.address.state, doc.address.city,address.country], doc);

查看byCityStateCountry":

view "byCityStateCountry":

emit([address.city,doc.address.state, doc.address.country], doc);

只是在第一个位置放一个标志来确定查询的类型，这样你就可以在一个视图中完成所有操作:

of just put a flag in the first place to determine the type of query, so you can do all in one View:

emit([1,address.country,doc.address.state, doc.address.city], doc);
emit([2,doc.address.state, doc.address.city,address.country], doc);
emit([3,address.city,doc.address.state, doc.address.country], doc);

用法:

?startkey=[1,"US"]&endkey=[1,"US",{}]
?startkey=[2,"FL"]&endkey=[2,"FL",{}]
?startkey=[3,"Miami"]&endkey=[3,"Miami",{}]

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