Update all the values of a field with a specific string in MongoDB?

To update all the values, use update() along with multi:true. Let us create a collection with documents −

> db.demo720.insertOne({"SubjectName":"MySQL"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5eaae7ca43417811278f5883")
}
> db.demo720.insertOne({"SubjectName":"Java"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5eaae7ce43417811278f5884")
}
> db.demo720.insertOne({"SubjectName":"C"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5eaae7d143417811278f5885")
}
> db.demo720.insertOne({"SubjectName":"C++"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5eaae7d543417811278f5886")
}

Display all documents from a collection with the help of find() method −

> db.demo720.find();

This will produce the following output −

{ "_id" : ObjectId("5eaae7ca43417811278f5883"), "SubjectName" : "MySQL" }
{ "_id" : ObjectId("5eaae7ce43417811278f5884"), "SubjectName" : "Java" }
{ "_id" : ObjectId("5eaae7d143417811278f5885"), "SubjectName" : "C" }
{ "_id" : ObjectId("5eaae7d543417811278f5886"), "SubjectName" : "C++" }

Following is the query to update all the values of the field “SubjectName” −

> db.demo720.update({},{$set:{SubjectName:"MongoDB"}},{multi:true});
WriteResult({ "nMatched" : 4, "nUpserted" : 0, "nModified" : 4 })

Display all documents from a collection with the help of find() method −

> db.demo720.find();

This will produce the following output −

{ "_id" : ObjectId("5eaae7ca43417811278f5883"), "SubjectName" : "MongoDB" }
{ "_id" : ObjectId("5eaae7ce43417811278f5884"), "SubjectName" : "MongoDB" }
{ "_id" : ObjectId("5eaae7d143417811278f5885"), "SubjectName" : "MongoDB" }
{ "_id" : ObjectId("5eaae7d543417811278f5886"), "SubjectName" : "MongoDB" }

AmitDiwan

Published on 15-May-2020 08:54:39

• Related Questions & Answers
• List all values of a certain field in MongoDB?
• Find all collections in MongoDB with specific field?
• Find all the non-distinct values of a field in MongoDB?
• Fetch specific field values in MongoDB
• MongoDB query to add up the values of a specific field in documents
• Limit number of values in a field with MongoDB?
• Return a specific field in MongoDB?
• Get the duplicate values of a field in MongoDB?
• How to run MongoDB query to update only a specific field value?
• Update object in array with a specific key in MongoDB
• Extract a MongoDB document with a specific string
• Find the document by field name with a specific value in MongoDB?
• Update only a specific value in a MongoDB document
• Update MongoDB field using value of another field?
• Want to update inner field in a MongoDB