Question

[MONGO]我有一些像这样的地方：

[
    { item: "journal",tags: ["blank", "red","blue","yellow"]},
    { item: "notebook",tags: ["red", "pink","green"]},
    { item: "paper", tags: ["red", "blank", "plain","black"]},
    { item: "planner",tags: ["blank", "blue","gray"]},
    { item: "postcard",tags: ["blue"] }
]

我想搜索带有1个数组搜索的标签：[“red”，“blank”，“black”]，如何获取项目，标签在aray搜索中包含至少1个元素。和排序。

期待结果：

[
    { item: "paper",tags: ["red", "blank", "plain","black"]},
    { item: "journal",tags: ["blank", "red","blue","yellow"]},
    { item: "notebook",tags: ["red", "pink","green"]},
    { item: "planner", tags: ["blank", "blue","gray"]},
]

Answer 1

如果要查找集合myitems中的所有文档，可以使用$or operator，projection和sort function。

以下是查询如何找到任何标记为＆＃34; red＆＃34;，＆＃34; blank＆＃34;或者＆＃34;黑色＆＃34;：

db.myitems.aggregate([
  {$project : 
    {tags: 1, item: 1, tag_count: {$size: "$tags" } }
  }, 
  {$match: 
    {$or: [{tags: "red"}, {tags: "blank"}, {tags: "black"}]} 
  }, 
  {$sort: {"tag_count": -1} } 
]);

这将返回如下内容：

{ "item" : "journal", "tags" : [ "blank", "red", "blue", "yellow" ], "tag_count" : 4 }
{ "item" : "paper", "tags" : [ "red", "blank", "plain", "black" ], "tag_count" : 4 }
{ "item" : "notebook", "tags" : [ "red", "pink", "green" ], "tag_count" : 3 }
{ "item" : "planner", "tags" : [ "blank", "blue", "gray" ], "tag_count" : 3 }

解释：

这使用MongoDB中的Aggregation pipeline，创建给定数据库的projection以获取＆＃34;标记＆＃34;大小，使用match projection和$or operator对标记进行过滤，最后对＆＃34;标记＆＃34;进行排序。大小

希望这有帮助。

在mongo中查询搜索元素数组

1 个答案: