how to remove a field from all documents using Java

[ajay]

One of the field in a collection has become obsolete and I want to remove
it from all documents using Java language. How do I go about doing this?

Thanks.

[matts]

Mongo().getDB("test").getCollection("bar").update( new BasicDBObject() ,
new BasicDBObject( "$unset" , new BasicDBObject( "badField" : 1 ) ) , false
, true );

Post by ajay
One of the field in a collection has become obsolete and I want to remove
it from all documents using Java language. How do I go about doing this?
Thanks.
-Ajay

[ajay]

Thanks. Is there a way to do this using Morphia?

Post by matts
Mongo().getDB("test").getCollection("bar").update( new BasicDBObject() ,
new BasicDBObject( "$unset" , new BasicDBObject( "badField" : 1 ) ) , false
, true );

Post by ajay
One of the field in a collection has become obsolete and I want to remove
it from all documents using Java language. How do I go about doing this?
Thanks.
-Ajay

[ajay]

I figured out how to do this in Morphia. Let me share with others. I
created a generic method for myself. Notice since the field being removed
may no longer be part of the POJO, I am disabling validation both for query
as well as for update-operations.

public <T> void removeField(Class<T> clazz, String fieldName) {
UpdateOperations<T> ops = ds.createUpdateOperations(clazz)
.disableValidation().unset(fieldName);
Query<T> query =
ds.createQuery(clazz).disableValidation().field(fieldName).exists();
UpdateResults<T> updateResults = ds.update(query, ops, false);
}


-Ajay