CODEWITHSUNDEEP
spring-data-mongodb
Johnny Bigoode
Johnny Bigoode

Reputation: 591

How may I update an array that's in a MongoDB using Spring?

I'm trying to update database information from some information I get from a Thymeleaf powered page. Basically each page is constructed using a single document from MongoDB. Now I'd like to allow some users to change this page, since the actual page is not that complex, I was giving a shot to this JavaScript plugin that would create text area divs and send them to server via Ajax (http://www.dyve.net/jquery/?editable).

Since the document has only unique fields, I can set the field id in the html to the name of the mongodb field, like product-description. I can send the id through and the update is really simple: 

public boolean updateValueWithKey(String id, String k, String v) {
    Criteria c = Criteria.where(id).is(id);
    Query q = new Query().addCriteria(c);
    Update u = u.set(k, v);
    WriteResult w = operations.updateFirst(q, u, clazz);
    return w.wasAcknowledged();
}

Where id is the document id code, k is the field name (key) and v the value.

But I realized that one particular part of the document has an array, but I don't understand how can I update a particular field of an array.

The Update class has a inner class called PushOperatorBuilder with a method called atPosition, which the docs mention that: "Forces values to be added at the given {@literal position}."

But I really don't understand how to use that, any attempt to reach that method from the instantiated Update object just gave me errors.

Help?

Upvotes: 0

Views: 4264

Answers (1)

s7vr
s7vr

Reputation: 75994

You can try postional operator to locate array field in a query followed by update at that position.

Something like

Criteria c = Criteria.where(id).is(id).and("array.key").is("oldvalue");
Query q = new Query().addCriteria(c);
Update u = new Update().set("array.$.key", "newvalue");
WriteResult w = mongoOperations.updateFirst(q, u, clazz);

Update at specific position

Criteria c = Criteria.where(id).is(id);
Query q = new Query().addCriteria(c);
Update u = new Update().push("arrayname").atPosition(position).each(newvalue);
WriteResult w = mongoOperations.updateFirst(q, u, clazz);

Upvotes: 5

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