MongoDB的：檢查是否在特定的子文檔數組存在值

Question

我有以下模式：

{ 
_id: objectID('593f8c591aa95154cfebe612'), 
name: 'test' 
businesses: [ 
{ 
    _id: objectID('5967bd5f1aa9515fd9cdc87f'), 
    likes: [objectID('595796811aa9514c862033a1'), objectID('593f8c591ba95154cfebe790')] 
} 
{ 
    _id: objectID('59579ff91aa9514f600cbba6'), 
    likes: [objectID('693f8c554aa95154cfebe146')] 
} 
    ] 
} 

我怎樣才能檢查的objectID（「593f8c591ba95154cfebe790」）存在於陣列business.likes其中businesses._id =的objectID （'59579ff91aa9514f600cbba6'）？

在上面的例子中，它應該返回false。

Answer 1

可以使用$elemMatch多個領域相同的子文檔中找到

db.collectionName.find({ 
    businesses: { 
    $elemMatch: { 
     _id: ObjectId("5967bd5f1aa9515fd9cdc87f"), 
     likes: ObjectId("593f8c591ba95154cfebe790") 
    } 
    } 
});