在mongodb中可以通過子對象查詢嗎？

Question

我有一個蒙哥DOC：

{ 
    "_id" : ObjectId("54eb5189ad9685bbb622ca52"), 
    "header" : { 
    "title" : "Project Name 1", 
    "header_img" : "project_name_1.png", 
    "project_stats" : { 
     "sqFt" : 20000, 
     "tons" : 300, 
     "duration" : "6 months", 
     "type" : "education facility", 
     "summary" : "Give quick summary of problem solved." 
    } 
}, 
"row_project_detail" : { 
    "project_logo" : "project_name_1_logo.png", 
    "header" : "Project Name 1 was a project where...", 
    "paragraph" : "blah blah blah blah" 
}, 
"row_1" : { 
    "img" : "project_name_2.png" 
}, 
"row_2" : { 
    "img_1" : "project_name_3.png", 
    "img_2" : "project_name_4.png" 
}, 
"row_3" : { 
    "img" : "project_name_5.png" 
}, 
"row_4" : { 
    "img" : "project_name_6.png" 
} 
} 

我試圖通過db.projects.find({ header: { title: "Project Name 1"} });查詢，但它並沒有產生結果。如何通過header對象中的title鍵查詢？這是可能的還是我只需要複製header子對象中的title密鑰並將其放在文檔的根目錄下？

Answer 1

使用點表示法：

db.projects.find({ "header.title": "Project Name 1"});