如何在 mongodb 中添加到数组

Question

I just wanted to know how to add to a array in a mongodb document because I only know how to reassign the whole array in the document.

Answer 1

As reported in MongoDB docs, if you have the following document in the students

collection:

{
   "_id" : 5,
   "quizzes" : [
      { "wk": 1, "score" : 10 },
      { "wk": 2, "score" : 8 },
      { "wk": 3, "score" : 5 },
      { "wk": 4, "score" : 6 }
   ]
}

you can add the following documents to the quizzes array with the following command:

db.students.update(
   { _id: 5 },
   {
     $push: {
       quizzes: {
          $each: [ { wk: 5, score: 8 }, { wk: 6, score: 7 }, { wk: 7, score: 6 } ]
       }
     }
   }
)