How to find all the children for its parent in Jquery?

Question

I'm using Codeigniter and Jquery with AJAX method to query data from two tables in my database with select join from table group with table cat.

This is table description

Table1: cat

======c_id======fk_group_id====cat_name===
======1========1==============cat1=======
======2========1==============cat2=======
======3========1==============cat3=======
======4========1==============cat4=======

Table2: cat_group.

======gid=======gname====gstat============
======1========1=========1==============
======2========1=========1==============
======3========1=========1==============
======4========1=========1==============

Here is my Model:

This function will selct from table cat_group join with table Cat on gid = cat.fk_group_id.

public function cat(){

    $this->db->select('cat_group.*, cat.*');
    $this->db->from('cat_group');
    $this->db->join('cat', 'cat.fk_group_id = cat_group.gid','all')->where('cat_group.gstatus = 1');
    return $this->db->get()->result();
}

My function in Controller: I call method cat from Model and echo data as Json_encode to the client browsers

public function select_cat_by_group(){
    $this->load->model("main/slide_cat_m");
    $val = $this->slide_cat_m->cat();
    if(!$val){
        return false;
    }else{
       echo json_encode($val);
    }
}

Jquery Ajax

 $.ajax({
     method: "GET",
     url: '<?PHP echo base_url('main/select_cat_by_group');?>',
     dataType: "Json",
     success: function (data) {
           $.each(data, function (i, val) {
              if(val.fk_group_id = gid){
                    //I want to select all the rows in table cat where  fk_groupd_id = gid of table cat_group but I can't 
              }
           });
     }
 })

My Json

[{"gid":"1","gtype":"1","g_name":"a","gstatus":"1","gad_stat":"1","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"1","fk_group_id":"1","cat_name":"fuck1","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"5","gtype":"2","g_name":"a","gstatus":"1","gad_stat":"0","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"5","fk_group_id":"5","cat_name":"cat_name","c_status":"1","type_for_group":"2","img":"9.jpg","src":"asset\/img\/main"},{"gid":"5","gtype":"2","g_name":"a","gstatus":"1","gad_stat":"0","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"6","fk_group_id":"5","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"5","gtype":"2","g_name":"a","gstatus":"1","gad_stat":"0","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"7","fk_group_id":"5","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"5","gtype":"2","g_name":"a","gstatus":"1","gad_stat":"0","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"8","fk_group_id":"5","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"6","gtype":"1","g_name":"a","gstatus":"1","gad_stat":"1","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"9","fk_group_id":"6","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"6","gtype":"1","g_name":"a","gstatus":"1","gad_stat":"1","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"10","fk_group_id":"6","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"6","gtype":"1","g_name":"a","gstatus":"1","gad_stat":"1","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"15","fk_group_id":"6","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"6","gtype":"1","g_name":"a","gstatus":"1","gad_stat":"1","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"16","fk_group_id":"6","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"6","gtype":"1","g_name":"a","gstatus":"1","gad_stat":"1","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"17","fk_group_id":"6","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"6","gtype":"1","g_name":"a","gstatus":"1","gad_stat":"1","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"18","fk_group_id":"6","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"6","gtype":"1","g_name":"a","gstatus":"1","gad_stat":"1","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"19","fk_group_id":"6","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"7","gtype":"1","g_name":"a","gstatus":"1","gad_stat":"0","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"20","fk_group_id":"7","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"7","gtype":"1","g_name":"a","gstatus":"1","gad_stat":"0","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"21","fk_group_id":"7","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"7","gtype":"1","g_name":"a","gstatus":"1","gad_stat":"0","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"22","fk_group_id":"7","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"7","gtype":"1","g_name":"a","gstatus":"1","gad_stat":"0","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"23","fk_group_id":"7","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"7","gtype":"1","g_name":"a","gstatus":"1","gad_stat":"0","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"24","fk_group_id":"7","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"7","gtype":"1","g_name":"a","gstatus":"1","gad_stat":"0","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"25","fk_group_id":"7","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"},{"gid":"7","gtype":"1","g_name":"a","gstatus":"1","gad_stat":"0","gsrc":"asset\/img\/cat\/","gimg":"cat_ads.jpg","c_id":"26","fk_group_id":"7","cat_name":"cat_name","c_status":"1","type_for_group":"1","img":"9.jpg","src":"asset\/img\/main"}]

Answer 1

You did small mistake in model. However it should be:

$this->db->select('cat_group.*, cat.*');
    $this->db->from('cat');
    $this->db->join('cat_group', 'cat.fk_group_id = cat_group.gid','all')->where('cat_group.gstatus = 1');
    return $this->db->get()->result();

It must return all the rows of cat where fk_groupd_id = gid. Now you should parse the json result.

UPDATE:

$.ajax({
   type: "POST",
   url: 'YOUR_URL',
   dataType:'JSON',
   success: function(data) {

           $.each(data, function(index, element) {
           //console.log(index);
           //alert(element.c_id);               
           console.log(element.c_id);
           console.log(element.cat_name); // here console.log() is used to debug the data.
        });

      }
})

It's up to you now how you will display the data in HTML. You can check this example as how to parse json object and display them into DOM: how to parse json data with jquery / javascript?