<script>

  $(document).ready(function (){
            var i; i=0;
    $.ajax({
        url: '/display_rpt_expectedtableSchema?rpt_step_id=<%=@rpt_step_id%>&header_data=true',
        success: function (data, st) {
            if (st == "success") {
                var columnData = jQuery.parseJSON(data)
               // for(i=0;i<columnData.source.length; i++)  {alert('how many loops'); alert(i);
                jQuery("#schemalist").jqGrid({
                    //url : '/display_rpt_expectedtableSchema?rpt_step_id=<%=@rpt_step_id%>&header_data=false',
                    datastr: columnData.source,
                    pager: '#schemaPager',
                    datatype: "jsonstring",
                    colNames: ['ExpTableName','ExpColumn', 'ExpType', 'ExpSize'],
                    cmTemplate: { title: false },
                    //colModel:ColM,
                    /*colModel:  [
                        {name:'tableName',index:'tableName', width:145,jsonmap:'columns'+'.'+i+'.'+'tableName'},

                        {name:'name',index:'name', width:145,jsonmap:'columns'+'.'+i+'.'+'name'},
                        {name:'type',index:'type', width:145,jsonmap:'columns'+'.'+i+'.'+'type'},
                        {name:'size',index:'size', width:145,jsonmap:'columns'+'.'+i+'.'+'size'}
                    ],*/
                    colModel:  [
                        {name:'tableName',index:'tableName', width:145,jsonmap:'tableName'},
                        {name:'name',index:'name', width:145,jsonmap:'name'},
                        {name:'type',index:'type', width:145,jsonmap:'type'},
                        {name:'size',index:'size', width:145,jsonmap:'size'}
                    ],

                    //jsonReader:{repeatitems: false,root:'source'+'.'+i+'.'+'columns'},
                    jsonReader:{repeatitems: false,root:'source.0.columns'},
                    rowNum: 25,
                    viewrecords: true,
                    caption: "Expected Schema",
                    height: 600,
                    width: 600,
                    //multiselect: true,
                    autoFitColumns: true,
                    loadonce: true,
                    autoencode: true,
                    shrinkToFit: false,
                    ignoreCase: true
                });

                    $("#schemalist").jqGrid('navGrid','#schemaPager',{edit:false,add:false,del:false});

            }

      //      }
        },
        error: function () {
            alert("Error with AJAX callback");
        }
    });

  });

and Here is my JSON Object
{"source":[{"id":1,"columns":[{"name":"Jdate","type":"Date","size":"0","tableName":"c1"},
{"name":"CustId","type":"Int","size":"0","tableName":"c2"},
{"name":"Jdate","type":"Date","size":"0","tableName":"c3"},
{"name":"Jdate","type":"Date","size":"0","tableName":"c4"},
{"name":"Jdate","type":"Date","size":"0","tableName":"c5"}]},
{"id":2,"columns":[{"name":"Amt","type":"Money","size":" 0","tableName":"Loan"},
{"name":"Tenure","type":"int","size":" 0","tableName":"Loan"}]},
{"id":3,"columns":[{"name":"Amt","type":"Money","size":" 0","tableName":"xyz"},
{"name":"Tenure","type":"int","size":" 0","tableName":"xyz"}]}]} 


Data displaying in grid with first list which is "ID":1 but not "id" 2,3
({"name":"Jdate","type":"Date","size":"0","tableName":"c1"},
{"name":"CustId","type":"Int","size":"0","tableName":"c2"},
{"name":"Jdate","type":"Date","size":"0","tableName":"c3"},
{"name":"Jdate","type":"Date","size":"0","tableName":"c4"},
{"name":"Jdate","type":"Date","size":"0","tableName":"c5"})


Because Here I have used JsonReader as root: 'source.0.columns'.
My requirement is to load whole json object data in the above grid (i.e have to load id '1','2','3')
I tried to loop it in jsonReader:{repeatitems: false,root:'source'+'.'+i+'.'+'columns'} by getting count of the "columns" list in the object (looping the whole the grid). But Grid is loading values for first json list and not loading other 2 lists.
Is there any other approach to load given json object with the data in grid? Is there any way to loop the jsonreader to display all the jsonlist data?
How to read this kind json data in grid. am I going in right direction?
Please help me on this.