javascript prototype inheritance - shared property

Question

I have saved a property _data in prototype as a definition for all created objects.

 function A() {}
 A.prototype._data = [];

Now all objects created from A have property _data.

I'd like prototype inheritance, where _data of prototype will have _data values from all prototypes in prototype chain.

Don't know direct way, in this example I use a getter get().

 function A() {}

 A.prototype._data = [];

 A.prototype.add = function(rec) {
   this.__proto__._data.push(rec);
 }

 A.prototype.get = function() {
   if(typeof this.__proto__.constructor.prototype.get == 'function')
   {
     return this.__proto__.constructor.prototype.get().concat(this.__proto__._data);
   }
   else
   {
     return this.__proto__._data || [];
   }
 }

 function B() {}
 B.prototype = Object.create(A.prototype, { constructor: { value: B }});
 B.prototype._data = [];

When I create object a with values aa and object b with value bb, b.get() returns [aa, bb]. And later if _data of prototype A will be extended with aaaa, function b.get() returns [aa, aaaa, bb].

 var a = new A(), b = new B();

 a.add('aa');
 b.add('bb');
 console.log(b.get()); // [aa, bb]

 a.add('aaaa');
 console.log(b.get()); // [aa, aaaa, bb]

 // EDITED - _data in A prototype shoud be without B
 console.log(a.get()); // [aa, aaaa]

Is it a good (standard) way how to achieve this? I mean using constructor correction while Object.create and reference parent prototype with constructor.prototype?

Here is a demo: http://jsfiddle.net/j9fKP/

Reason for all of this is field definition for scheme in ORM library, where inheritance of schemes is allowed. Child scheme has to have all fields from parent scheme.

Answer 1

 function A() {}
     A.prototype._data = [];

 A.prototype.add = function(rec) {
   this._data.push(rec);
 }

 A.prototype.get = function() {
   return this._data;
 }

 function B() {}
 B.prototype = Object.create(A.prototype, { constructor: { value: B    }});

 B.prototype._data = [];

 B.prototype.get = function() {
   return A.prototype._data.concat(this._data);
 }  

 a.add('aa');
 b.add('bb');
 console.log(b.get()); // [aa, bb]

 a.add('aaaa');
 console.log(b.get()); // [aa, aaaa, bb]

Fiddle