Question

I am quite new to CouchDB and have a very basic question:

Is there any possibility to pass a variable from the client into the map function, e.g.:

function (doc, params) {
    if (doc.property > params.property) emit(doc, null);
}

Thanks for your help,
Christian

Answer 1

While Dominic’s answer is true, the example in the actual question can probably be implemented as a map function with an appropriate key and a query that includes a startkey. So if you want the functionality that you show in your example you should change your view to this:

function(doc) {
  if( doc.property )
    emit( doc.property, null);
}

And then your query would become:

/db_name/_design/view_doc/_view/view_name?startkey="property_param"&include_docs=true

Which would give you what your example suggests you’re after.

This is the key (puns are funny) to working with CouchDB: create views that allow you to select subsets of the view based on the key using either key, keys or some combination of startkey and/or endkey