Mongodb - 包含元素且不包含另一个元素的数组

Question

我正在尝试查询我的mongodb集合之一,如下所示:

> db.collection.find()
{name: "foo", things: [{stuff:"banana", value: 1}, {stuff:"apple", value: 2}, {stuff:"strawberry", value: 3}]}
{name: "bar", things: [{stuff:"banana", value: 4}, {stuff:"pear", value: 5}]}
...

我的目标是列出所有things包含元素stuff=banana但不包含元素的对象stuff=apple

我试过这样的事情:

db.transactions.find({
  "things": {
    $elemMatch: {
      "stuff": "banana", 
      $ne: {
        "stuff": "apple"
      }
    }
  }
)

但它不起作用.有任何想法吗？

Answer 1

以下查询将获取things包含stuff=banana但不包含元素的字段的所有文档的列表stuff=apple:

db.test.find({"$and":[{"things.stuff":"banana"}, {"things.stuff":{$ne:"apple"}}]})

Answer 2

使用$not和$and运算符：

db.collection.find({

   $and:[
    {"things": {$elemMatch: {  "stuff": "banana"  }}},
    {"things": {$not: {$elemMatch: { "stuff": "apple"}}}}
  ]

});