Mongodb - E QUERY SyntaxError: Unexpected identifier - mongodb

Question

Here is an example of my MongoDb structure :
{
"id" : 1,
"children" : [
{
"id" : 2,
"status" : " fsdfsdf "
},
{
"id" : 3,
"status" : " ffdfg "
},
{
"id" : 4,
"status" : " fsdfsdfsdfdsf "
}
]
}
I wanted to trim records in mongodb, so i did :
db.getCollection('myCollectionName').find().forEach(function (doc){
for (subDoc of doc.children) {
if(typeof subDoc.status === 'string') {
subDoc.theText = subDoc.theText.trim();
}
}
db.getCollection('myCollectionName').save(doc);
})
But i got this error :
E QUERY SyntaxError: Unexpected identifier

Answer 1

You use wrong identifier — the array item doesn't have theText identifier.
var docs = db.getCollection('myCollectionName').find()
docs.forEach(function (doc) {
for (subDoc of doc.children) {
if(typeof subDoc.status === 'string') {
subDoc.status = subDoc.status.trim();
}
}
db.getCollection('myCollectionName').save(doc);
})
Step by Step instructions
Open local mongo shell with db stackoverflow
⋊> ~ mongo stackoverflow
MongoDB shell version v3.4.1
connecting to: mongodb://127.0.0.1:27017/stackoverflow
MongoDB server version: 3.4.0
Insert one (your) document
> db.getCollection('myCollectionName').insertOne({
... "id" : 1,
... "children" : [
... {
... "id" : 2,
... "status" : " fsdfsdf "
... },
... {
... "id" : 3,
... "status" : " ffdfg "
... },
... {
... "id" : 4,
... "status" : " fsdfsdfsdfdsf "
... }
... ]
... })
{
"acknowledged" : true,
"insertedId" : ObjectId("588b4984522a4f31ff6bc738")
}
Find inserted document
> db.getCollection('myCollectionName').findOne()
{
"_id" : ObjectId("588b4984522a4f31ff6bc738"),
"id" : 1,
"children" : [
{
"id" : 2,
"status" : " fsdfsdf "
},
{
"id" : 3,
"status" : " ffdfg "
},
{
"id" : 4,
"status" : " fsdfsdfsdfdsf "
}
]
}
I use findOne because I know in db only one document. In normal situation you need use find and pretty to find all document in collection
> db.getCollection('myCollectionName').find().pretty()
Find documents in collection and save cursor in variable
> var docs = db.getCollection('myCollectionName').find()
Run function for trim only field status in array children in documents
> docs.forEach(function (doc) {
... for (subDoc of doc.children) {
... if(typeof subDoc.status === 'string') {
... subDoc.status = subDoc.status.trim();
... }
... }
...
... db.getCollection('myCollectionName').save(doc);
... })
Improvement for production: find only documents with field children and check fields into document exists.
Check the result (find the document)
> db.getCollection('myCollectionName').findOne()
{
"_id" : ObjectId("588b4984522a4f31ff6bc738"),
"id" : 1,
"children" : [
{
"id" : 2,
"status" : "fsdfsdf"
},
{
"id" : 3,
"status" : "ffdfg"
},
{
"id" : 4,
"status" : "fsdfsdfsdfdsf"
}
]
}