更新所以 Mohammad Faisal 有最好的解決方案。但是，當添加新文檔時它會中斷，哈哈！所以我從他的代碼中學到了很多東西并對其進行了修改，它可以工作！=) 代碼一直在底部。但這就是我所說的......所以我有這個文件{"_id":"5ddea2e44eb407059828d740","projectname":"wdym","username":"easy","likes":0,"link":["ssss"]}{"_id":"5ddea2e44eb407059822d740","projectname":"thechosenone","username":"easy","likes":30,"link":["ssss"]}{"_id":"5ddea2e44eb407059828d740","projectname":"thanos","username":"wiley","likes":10,"link":["ssss"]}基本上我想要的是包含最高贊及其相關項目名稱的文檔例如輸出將是"projectname":"thechosenone","username":"easy","likes":30},{"projectname":"thanos","username":"wiley","likes":10,}我為此擁有的代碼如下db    .collection("projects")    .aggregate([      {        $group: {          _id: { username: "$username" },          likes: { $max: "$likes" }        }      },      {        $project:{projectname:1}      }    ])$project 給了我一個奇怪的輸出。但是，如果沒有 $project，輸出是正確的。但我想投影項目名稱、用戶和最高點贊數。謝謝你聽我說:)