MongoDB使用$或查找查詢並計數

Question

我在mongodb中使用$或查詢遇到了小問題，我有一個具有以下模式的文檔的集合。它有一個角色和skill_set鍵，每個角色都有一些相關的技能組合。

[ 
{ 
    "skill_set" : [ 
     { 
      "skill_name" : "Project Planning" 
     }, 
     { 
      "skill_name" : "Delivery Management" 
     }, 
     { 
      "skill_name" : "Resource Management" 
     }, 
     { 
      "skill_name" : "Stakeholder Management" 
     }, 
     { 
      "skill_name" : "Agile Project Management" 
     }, 
     { 
      "skill_name" : "Change Management" 
     } 
    ], 
    "role" : "Project Manager" 
}, 
{ 
    "skill_set" : [ 
     { 
      "skill_name" : "Project Planning" 
     }, 
     { 
      "skill_name" : "Delivery Management" 
     }, 
     { 
      "skill_name" : "Resource Management" 
     }, 
     { 
      "skill_name" : "Stakeholder Management" 
     }, 
     { 
      "skill_name" : "Agile Project Management" 
     }, 
     { 
      "skill_name" : "Change Management" 
     }, 
     { 
      "skill_name" : "Financial Management" 
     }, 
     { 
      "skill_name" : "Sales, Marketing and Customer Service " 
     }, 
     { 
      "skill_name" : "Strategic Input" 
     } 
    ], 
    "role" : "Sr Project Manager" 
}, 
{ 
    "skill_set" : [ 
     { 
      "skill_name" : "Project Planning" 
     }, 
     { 
      "skill_name" : "Delivery Management" 
     }, 
     { 
      "skill_name" : "Resource Management" 
     }, 
     { 
      "skill_name" : "Stakeholder Management" 
     }, 
     { 
      "skill_name" : "Agile Project Management" 
     }, 
     { 
      "skill_name" : "Change Management" 
     }, 
     { 
      "skill_name" : "Financial Management" 
     }, 
     { 
      "skill_name" : "Sales, Marketing and Customer Service " 
     }, 
     { 
      "skill_name" : "Strategic Input" 
     } 
    ], 
    "role" : "Delivery Manager" 
}, 
{ 
    "skill_set" : [ 
     { 
      "skill_name" : "Test Planning" 
     }, 
     { 
      "skill_name" : "Technlogy Expertise" 
     }, 
     { 
      "skill_name" : "Team Player" 
     }, 
     { 
      "skill_name" : "Communication" 
     }, 
     { 
      "skill_name" : "Design and Architecture" 
     }, 
     { 
      "skill_name" : "Requirement Understanding" 
     }, 
     { 
      "skill_name" : "Task Management" 
     } 
    ], 
    "role" : "Tester" 
} 
] 

我想搜索與作用匹配skill_set文件，這些文件我能夠使用查詢獲取。

{"$or":[{"skill_set.skill_name":"Project Planning"},{"skill_set.skill_name":"Strategic Input"},{"skill_set.skill_name":"Delivery Management"}]},{"_id":0} 

輸出，用於查詢

[ 
{ 
    "skill_set" : [ 
     { 
      "skill_name" : "Project Planning" 
     }, 
     { 
      "skill_name" : "Delivery Management" 
     }, 
     { 
      "skill_name" : "Resource Management" 
     }, 
     { 
      "skill_name" : "Stakeholder Management" 
     }, 
     { 
      "skill_name" : "Agile Project Management" 
     }, 
     { 
      "skill_name" : "Change Management" 
     } 
    ], 
    "role" : "Project Manager" 
}, 
{ 
    "skill_set" : [ 
     { 
      "skill_name" : "Project Planning" 
     }, 
     { 
      "skill_name" : "Delivery Management" 
     }, 
     { 
      "skill_name" : "Resource Management" 
     }, 
     { 
      "skill_name" : "Stakeholder Management" 
     }, 
     { 
      "skill_name" : "Agile Project Management" 
     }, 
     { 
      "skill_name" : "Change Management" 
     }, 
     { 
      "skill_name" : "Financial Management" 
     }, 
     { 
      "skill_name" : "Sales, Marketing and Customer Service " 
     }, 
     { 
      "skill_name" : "Strategic Input" 
     } 
    ], 
    "role" : "Sr Project Manager" 
}, 
{ 
    "skill_set" : [ 
     { 
      "skill_name" : "Project Planning" 
     }, 
     { 
      "skill_name" : "Delivery Management" 
     }, 
     { 
      "skill_name" : "Resource Management" 
     }, 
     { 
      "skill_name" : "Stakeholder Management" 
     }, 
     { 
      "skill_name" : "Agile Project Management" 
     }, 
     { 
      "skill_name" : "Change Management" 
     }, 
     { 
      "skill_name" : "Financial Management" 
     }, 
     { 
      "skill_name" : "Sales, Marketing and Customer Service " 
     }, 
     { 
      "skill_name" : "Strategic Input" 
     } 
    ], 
    "role" : "Delivery Manager" 
} 
] 

在輸出是清晰可見，3超過4個角色被取出。除此之外，我希望技能組匹配角色.ie。

在給定的查詢我在尋找項目規劃或交付管理或戰略投入角色，我想爲角色項目經理skill_match_count = 2已經2比賽在他的技能組合，即我想要的東西象下面。

[ 
{ 
    "role" : "Project Manager", 
    "skill_match_count" : 2 
}, 
{ 
    "role" : "Sr Project Manager", 
    "skill_match_count" : 3 
}, 
{ 
    "role" : "Delivery Manager", 
    "skill_match_count" : 3 
} 
] 

Answer 1

你需要做的，就是$filter的skill_set陣列與$or條件，然後$project的$size您的過濾數組：

db.roles.aggregate([ 
    { 
     $project: { 
      role: 1, 
      filtered_skill_set: { 
       $filter: { 
        input: "$skill_set", 
        as: "skill", 
        cond: { 
         $or: [ 
          { $eq: ["$$skill.skill_name", "Project Planning"] }, 
          { $eq: ["$$skill.skill_name", "Strategic Input"] }, 
          { $eq: ["$$skill.skill_name", "Delivery Management"] } 
         ] 
        } 
       } 
      } 
     } 
    }, 
    { 
     $project: { 
      role: 1, 
      skill_match_count: { 
       $size: "$filtered_skill_set" 
      } 
     } 
    } 
]) 

這將導致你期望包括角色的輸出在skill_match_count中爲0。如果要排除它們，則可以在末尾添加另一個$match流水線階段：

{ 
    $match: { 
     skill_match_count: { 
      $gt: 0 
     } 
    } 
}