$all

Equivalent to $and Operation相当于$and操作

The $all is equivalent to an $and operation of the specified values; i.e. the following statement:$all相当于指定值的$and运算；即以下声明：

{ tags: { $all: [ "ssl" , "security" ] } }

is equivalent to:相当于：

{ $and: [ { tags: "ssl" }, { tags: "security" } ] }

Nested Array嵌套数组

When passed an array of a nested array (e.g. [ [ "A" ] ] ), $all matches documents where the field contains the nested array as an element (e.g. field: [ [ "A" ], ... ]), or the field equals the nested array (e.g. field: [ "A" ]).当传递一个嵌套数组的数组（例如[ [ "A" ] ]）时，$all会匹配字段包含嵌套数组作为元素的文档（例如field: [ [ "A" ], ... ]），或者字段等于嵌套数组（例如field: [ "A" ]）。

For example, consider the following query:例如，考虑以下查询：

db.articles.find( { tags: { $all: [ [ "ssl", "security" ] ] } } )

The query is equivalent to:该查询相当于：

db.articles.find( { $and: [ { tags: [ "ssl", "security" ] } ] } )

which is equivalent to:其等价于：

db.articles.find( { tags: [ "ssl", "security" ] } )

As such, the $all expression matches documents where the tags field is an array that contains the nested array [ "ssl", "security" ] or is an array that equals the nested array:因此，$all表达式匹配tags字段是包含嵌套数组[ "ssl", "security" ]的数组或等于嵌套数组的数组的文档：

tags: [ [ "ssl", "security" ], ... ]
tags: [ "ssl", "security" ]

Empty Array空数组

When passed an empty array, $all matches no documents.当传递一个空数组时，$all不匹配任何文档。

Use $all to Match Values使用$all匹配值

The following operation uses the $all operator to query the inventory collection for documents where the value of the tags field is an array whose elements include appliance, school, and book:以下操作使用$all运算符查询inventory集合中的文档，其中tags字段的值是一个数组，其元素包括appliance、school和book：

db.inventory.find( { tags: { $all: [ "appliance", "school", "book" ] } } )

The above query returns the following documents:上述查询返回以下文档：

{
   _id: ObjectId("5234cc89687ea597eabee675"),
   code: "xyz",
   tags: [ "school", "book", "bag", "headphone", "appliance" ],
   qty: [
          { size: "S", num: 10, color: "blue" },
          { size: "M", num: 45, color: "blue" },
          { size: "L", num: 100, color: "green" }
        ]
}

{
   _id: ObjectId("5234cc8a687ea597eabee676"),
   code: "abc",
   tags: [ "appliance", "school", "book" ],
   qty: [
          { size: "6", num: 100, color: "green" },
          { size: "6", num: 50, color: "blue" },
          { size: "8", num: 100, color: "brown" }
        ]
}

Use $all with $elemMatch将$all与$elemMatch一起使用

If the field contains an array of documents, you can use the $all with the $elemMatch operator.如果字段包含文档数组，则可以将$all与$elemMatch运算符一起使用。

The following operation queries the inventory collection for documents where the value of the qty field is an array whose elements match the $elemMatch criteria:以下操作查询inventory集合中的文档，其中qty字段的值是一个数组，其元素符合$elemMatch条件：

db.inventory.find( {
                     qty: { $all: [
                                    { "$elemMatch" : { size: "M", num: { $gt: 50} } },
                                    { "$elemMatch" : { num : 100, color: "green" } }
                                  ] }
                   } )

The query returns the following documents:查询返回以下文档：

{
   _id: ObjectId("5234ccb7687ea597eabee677"),
   code: "efg",
   tags: [ "school", "book"],
   qty: [
      { size: "S", num: 10, color: "blue" },
      { "size: "M", num: 100, color: "blue" },
      { size: "L", num: 100, color: "green" }
   ]
}

{
   _id: ObjectId("52350353b2eff1353b349de9"),
   code: "ijk",
   tags: [ "electronics", "school" ],
   qty: [
      { size: "M", num: 100, color: "green" }
   ]
}

The $all operator exists to support queries on arrays. But you may use the $all operator to select against a non-array field, as in the following example:$all运算符的存在是为了支持对数组的查询。但是，您可以使用$all运算符对非数组字段进行选择，如下例所示：

db.inventory.find( { "qty.num": { $all: [ 50 ] } } )

However, use the following form to express the same query:但是，使用以下表单表示相同的查询：

db.inventory.find( { "qty.num" : 50 } )

Both queries will select all documents in the inventory collection where the value of the num field equals 50.这两个查询都将选择inventory集合中num字段值等于50的所有文档。