如何从couchdb中的文档列出数据类型

Question

Is there any opprtunity to list all data types of a document in couchdb like string, object,integer ?

I'm using only curl with a Windows machine.

Answer 1

If you desire to use purely CURL on the client side you will need to create a design document to answer your query. The design document would have the following mapping function:

function(doc) {
    function obj_to_types( obj ){
        var types = {};
        Object.keys( obj ).forEach( function( k ) {
            var prop = obj[k];
            var type = typeof prop;
            var typeValue;
            if( type == "object" ){
                typeValue = obj_to_types( prop );
            }else{
                typeValue = type;
            }
            types[k] =typeValue;
        });
        return types;
    }
    emit(doc.id, obj_to_types( doc ));
}

This will produce output for each document such as:

{
_id: "string",
_rev: "string",
format: {
  0: "number",
  1: "number",
  2: "number"},
etc: "string"
}

Answer 2

CouchDB is using JSON, and JSON does have a limited set of datatypes, described here: http://json.org/

Any higher level datatype like "DateTime" or such, are a matter of format and not standardized.