MongoDb Titlecase in Collection - mongodb

Question

In my collection i need to change the firstname and lastname to be in Titlecase.since its in nested array i couldn't proceed.
db.users.find()
{
"users" : {
"assigned" :[
{
"firstName" : "naveen",
"lastName" : "bala",
},
{
"firstName" : "SHAJU",
"lastName" : "HARI",
},
{
"firstName" : "PADMANESH",
"lastName" : "NC",
}
]
}
}
I need the result to be like
{
"firstName" : "Padmanesh",
"lastName" : "Nc",
}
Tried this code below
function titleCase(str) {
return str && str.toLowerCase().split(/\s/).map(function(word) {
return word && word.replace(word[0], word[0].toUpperCase());
}).join(' ');
}
db.users.find().forEach(function(doc){
db.users.updateOne(
{ "_id": doc._id },
{ "$set": { "firstName": titleCase(doc.firstName) } }
);
});

Answer 1

The most efficient way is to use updateMany(). You can see how the titleCase operators work here: https://mongoplayground.net/p/xdePfeBvIQ1
https://docs.mongodb.com/master/reference/method/db.collection.updateMany/index.html
This should do it for you, you can match using the first arg if needed.
Please double check the user schema is correct in your question. If its not this will need to be tweaked. It expects each user doc contains a users object with an assigned property.
db.users.updateMany({}, [{
$set: {
"users.assigned": {
$map: {
input: "$users.assigned",
in: {
firstName: {
$concat:[
{$toUpper: {$substrCP: ["$$this.firstName", 0, 1]}},
{$toLower: {$substrCP: ["$$this.firstName", 1, {$strLenCP: "$$this.firstName"}]}},
]
},
lastName: {
$concat:[
{$toUpper: {$substrCP: ["$$this.lastName", 0, 1]}},
{$toLower: {$substrCP: ["$$this.lastName", 1, {$strLenCP: "$$this.lastName"}]}},
]
}
}
}
}
}
}])

Answer 2

An alternative, to do it on the mongo shell :
var titleCase = function (str) {
return (
str &&
str
.toLowerCase()
.split(/\s/)
.map(function (word) {
return word && word.replace(word[0], word[0].toUpperCase());
})
.join(" ")
);
};
db.users.find().forEach(function (doc) {
var a = doc.users.assigned;
a.forEach(function (person, index) {
var setop = `users.assigned.` + index + `.firstName`;
var uppered = titleCase(person.firstName);
db.users.updateOne(
{ _id: doc._id, "users.assigned.firstName": person.firstName },
{ $set: { [setop]: uppered } }
);
});
});