问题
I'm trying to add an "Instructors" array into an already existing "Camps" array.
The hierarchical structure looks something like this:
owner = {
email : 'john.smith@gmail.com',
password : 'mypassword',
firstName : 'john',
lastName : 'smith',
camps : [
{
name : 'cubs-killeen',
location : 'killeen',
manager : {name: 'joe black', email: '', password: ''},
instructors : [
{
firstName : 'bill',
lastName : 'jones',
classes : []
},
{
firstName : 'jill',
lastName : 'jones',
classes : [],
},
],
students : []
}
]
};
I am using Node Express with MongoJS and have been able to successfully add an owner and add "camps", however, in the "addInstructor" function, when I try and add "Instructors" to a particular camp that is when the problems occur. I get no error message, instead it simply appends the "Instructors" array AFTER the items in the camps array.
Any help would be greatly appreciated. Below is my full code, with working functions and then the one that is not working and below that is my mongodb output (albeit wrong):
CampRepository = function(){};
CampRepository.prototype.addOwner = function(owner, callback){
console.log(db);
db.owners.save(owner, function(err, saved){
if (err || !saved) {
console.log('broke trying to add owner : ' + err);
callback(err);
} else {
console.log('save was successful');
callback(null, saved);
}
});
};
CampRepository.prototype.addCamp = function(ownerEmail, camp, callback){
db.owners.update(
{email: ownerEmail},
{$push: {
camps:{
name: camp.name,
location: camp.location,
managerName: camp.managerName,
managerEmail: camp.managerEmail,
managerPassword: camp.managerPassword,
managerPayRate: camp.managerPayRate,
instructors: [],
students: []
}
}
}, function(err, saved){
if (err || !saved) {
console.log('broke trying to add camp ' + err);
callback(err);
} else {
console.log('save was successful');
callback(null, saved);
}
});
};
/*
THIS IS THE ONE THAT DOESN'T WORK
*/
CampRepository.prototype.addInstructor = function(ownerEmail, campName, instructor, callback){
db.owners.update(
{email: ownerEmail, 'camps.name': campName},
{$push: {
camps:{
instructors: {
firstName: instructor.firstName,
lastName: instructor.lastName,
email: instructor.email
},
}
}
}, function(err, saved){
if (err || !saved) {
console.log('broke trying to add camp ' + err);
callback(err);
} else {
console.log('save was successful');
callback(null, saved);
}
});
};
OUTPUT
{
"_id" : ObjectId("51c7b04d2746ef6078000001"),
"email" : "john.smith@gmail.com",
"firstName" : john,
"lastName" : smith,
"password" : "mypassword",
"camps" : [
{
"name" : "cubs-killeen",
"location" : "killeen",
"managerName" : "bill jones",
"managerEmail" : "bill@gmail.com",
"managerPassword" : "secretpasscode",
"instructors" : [ ],
"students" : [ ]
},
{ "instructors" : { "name" : "jon tisdale" } }
]
}
回答1:
You might need to take a look at this. you can achieve this using dot.notation It's very powerfull way to find or update items in a larger array of document scheme. If you still not able to achieve this i would happy to provide you the following code...
I've inserted a new owner2
owner2 = {
email : 'murali.ramakrishnan@gmail.com',
password : 'mypassword',
firstName : 'murali',
lastName : 'ramakrishnan',
camps : [
{
name : 'Rotary club',
location : 'trichy',
manager : {name: 'baskaran', email: 'baskaran@mit.edu', password: 'baskaran'},
instructors : [
{
firstName : 'baskaran',
lastName : 'subbiah',
classes : []
},
{
firstName : 'david',
lastName : 'nover',
classes : [],
},
],
students : []
}
]};
If you see we just need to add a new instructor as requested... let first add the document to the collection
db.try.insert(owner2);
here you go you have added a new document now, i'm going to create a new instructor object to insert @newly created owner2
instructor1 = {
firstName : 'lakshmi',
lastName : 'kanthan',
classes : []
};
above is the document object for new instructor you can perform this update in many ways, using mongodbs methods like
collection.update collection.findAndModify
if you want to insert or update any value to the sub-document we need to find using a dot.notation and push the sub-document to the document, here the code
db.try.update(
{'camps.name': "Rotary club" },
{
$push: { 'camps.$.instructors' : instructor1 }
}
)
the above code inserts a new record under the instructor field as in the field an array it just pushes the sub-document
End-Result
{
"_id" : ObjectId("51c7b222c0468dc711a60916"),
"email" : "murali.ramakrishnan@gmail.com",
"password" : "mypassword",
"firstName" : "murali",
"lastName" : "ramakrishnan",
"camps" : [
{
"name" : "Rotary club",
"location" : "trichy",
"manager" : {"name": "baskaran", "email": "baskaran@mit.edu", "password": "baskaran"},
"instructors" : [
{
"firstName" : "baskaran",
"lastName" : "subbiah",
"classes" : []
},
{
"firstName" : "david",
"lastName" : "nover",
"classes" : [],
},
{
"firstName" : "lakshmi",
"lastName" : "kanthan",
"classes" : [],
}
],
"students" : []
}
]};
来源：https://stackoverflow.com/questions/17267213/mongodb-adding-an-array-into-an-existing-array