mongoDB : renaming column name in collection [duplicate]

Question

I have a schema that looks like

name: 
value:
pattern:
XUknown:

I have 2 million documents in this collection.

Want
- I want to rename the column name XUknown to XString, so that the schema looks like

name: 
value:
pattern:
XString:  

How can I achieve this?

Thank you

Answer 1

You can use a $rename modifier.

db.collection.update({}, {$rename: {'XUknown': 'XString'}}, false, true);

You might also refresh your knowledge of update().

Answer 2

You can rename all the document by specify "Multi true" applicable to all the documents in the collection.

db.collection.update({}, {$rename: {'XUknown': 'XString'}}, {multi:true});