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mongodb的通配符查詢的一次失敗經(jīng)驗

發(fā)布時間：2020-05-30 12:41:52 來源：網(wǎng)絡(luò) 閱讀：2720 作者：sharpstill 欄目：MongoDB數(shù)據(jù)庫
我想find到mongo中的synonym_titles下面的嵌套子json下的影片名字段或者real_titles下面的嵌套子json下的影片名字段：


mongodb的通配符查詢的一次失敗經(jīng)驗


但是1,2這個info信息字段不確定
所以我想這么查詢：
db.search_correct_synonym.find({"synonym_titles.*":"聯(lián)邦調(diào)查局"})
但是失敗了，這種查詢是告訴mongo，我想找到無論哪一個field，只要包含value=聯(lián)邦調(diào)查局的field


最后的辦法，想要找到指定的片名，可以把這些片名copy出來放到一個獨立的field里，比如all_titles:["聯(lián)邦調(diào)查局", "帥哥在一九二五"]，可以對該字段建索引。
這樣就能根據(jù)db.search_correct_synonym.find({"all_titles":"聯(lián)邦調(diào)查局"})找到了

詳見http://stackoverflow.com/questions/6179871/mongodb-wildcard-in-the-key-of-a-query

As asked, this is not possible. The server issue you linked to is still under"issues we're not sure of".

MongoDB has some intelligence surrounding the use of arrays, and I think that's part of the complexity surrounding such a feature.

Take the following querydb.foo.find({ 'a.b' : 4 } ). This query will match the following documents.

{ a: { b: 4 } }{ a: [ { b: 4 } ] }

So what does "wildcard" do here?db.foo.find( { a.* : 4 } )Does it match the first document? What about the second?

Moreover, what does this mean semantically? As you've described, the query is effectively"find documents where any field in that document has a value of 4". That's a little unusual.

Is there a specific semantic that you're trying to achieve? Maybe a change in the document structure will get you the query you want.








thanks, that clarifies. More specifically, what I'm looking to do is wildcard just the specific node in the branch, i.e. any proper subfield of a. I'm not clear on how a.* says 'find where any field'. Isn't it 'find documents that have a top-level field 'a' with a subfield that matches 4'? – BradJun 1 '11 at 5:48

I think the confusion here is around "subfield". When I write{a:{b:4,c:2}}, I am saying that the valueais a JSON object. That JSON object has two keysbandc. The value of those keys are 4 & 2 respectively. When you are asking fora.*, you're effectively asking for syntax that loops through all of the keys in that JSON object. Your're not asking to"loop through an array", you're asking to"loop through an object's properties". That's a little unusual, which is why I'm asking for a specific use case here. – Gates VPJun 1 '11 at 17:15

@gates: I have a use case. myDocInMongo = {'someUnknownKey':{propToCheck:true}, 'someKnownKey':true}; Now, I want to find this document using the selector {someKnownKey:{$exists:true}} but i also want to make sure that none of the other keys have an object with the property propToCheck. So, like the following: {'*.propToCheck':{$exists:false}, {someKnownKey:{$exists:true}}} – doubletapMay 3 '12 at 17:57


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