title: Ext.data.Store.getById failed
body: <p>I have a store which is defined something like this:</p>
  
  <pre><code>var AdditionalGridData = new Ext.data.JsonStore(
                  {                       root: "result",
                      data: { result: Ext.decode(this.Data.AdditionalGridData) },
                      idProperty: 'iD',
                      fields: [
                              { name: "iD", type: "int", allowBlank: false }, //must match selected row's primary key
                              {name: "SomeText", type: "string" }
                          ]
                  });
  </code></pre>
  
  <p>So there is a time when I want to get an existing record by it's ID value. I call getById and it returns undefined. The store really contains the record that I am searching. Why could it not return my record?
  Read somewhere on the forums that:
  you need to pass record id (f.e. "ext-record-1") to Store.getById instead of your data ID (f.e. "1");
  Is this correct? Where do I get that record id?</p>