如何从MongoDB文档更新匹配某个值的数组？

Question

I'm a new mongoDB user, and I'm confused on how to update my document.

I have this document:

"_id" : ObjectId("5674c86aba97df0800995da7"),
"role" : "tutor",
"schools" : [ 
    "CHIJ Our Lady Of Good Counsel",
    "Nanyang Technological University"]

And I'd like to update the schools array from this document that matches a certain value from a var. I've tried like this:

var schools = [{ "name": "Nanyang Technological University (NTU)", "value": "nanyang-technological-university-(ntu)" }];

db.getCollection('clients').update(
// query
{
    "schools" : schools.name
},

// update
{

    $set:{"schools":[schools.value]}
},

// options
{
    "multi" : true,  // update only one document
    "upsert" : false  // insert a new document, if no existing document match the query
}
);

But of course, it's not working. Can anyone help me with this? Thanks!

I need the document to be displaying this value after update:

"_id" : ObjectId("5674c86aba97df0800995da7"),
"role" : "tutor",
"schools" : [ 
    "CHIJ Our Lady Of Good Counsel",
    "nanyang-technological-university-(ntu)"]

Answer 1

You could make use of the $ operator:

• for each item in the schools variable,
• find records, with the corresponding name in the schools array field.
• $set the new value at the position of the matched name using the $ positional operator.

code:

var schools=[{"name":"Nanyang Technological University", 
              "value":"nanyang-technological-university-(ntu)"}];


schools.forEach(function(i){
  db.clients.update({"schools.name":i.name},
            {$set:{"schools.$":i.value}},
            {"multi":true})
})