Append a string to the end of an existing field in MongoDB

Question

I have a document with a field containing a very long string. I need to concatenate another string to the end of the string already contained in the field.

The way I

Answer 1

db.getCollection('').update(
    // query 
    {},

    // update 
    {
        $set: {:this.+""}
    },

    // options 
    {
        "multi" : true,  // update only one document 
        "upsert" : false  // insert a new document, if no existing document match the query 
    });