Second-level linkage

City Controller aspects

Provincial area
Public Function one () {
   $data =db::table (' area ')->where ("Parent_id=0")->select ();
$AA = $data [0][' id ']+100;
$shi _ji=db::table ("area")->where ("Parent_id= ' $aa '")->select ();
$arr =[' data ' and $data, ' Shi ' and $shi _ji];
return View ("Show", [' arr ' = $arr]);
}
City-level areas
Public Function () {
   $id =request::instance ()->param ("id");
$b =db::table (' area ')->where ("Parent_id= ' $id '")->select ();
return View ("Show1", [' arr ' = $b]);
}
Province
Public Function three () {
   $id =request::instance ()->param ("id");
$b =db::table (' area ')->where ("Parent_id= ' $id '")->select ();
return View ("Show2", [' arr ' = $b]);
}

  //html page Show page shows provincial city

<table>
<tr>
<td> Provincial:</td>
<td>
<select name= "" id= "" class= "one" >
<option value= "Please select" > Please select </option>
{volist name= "arr.data" id= "V"}
<option value= "{$v. ID}" >{$v .name}</option>
{/volist}
</select>
</td>
<td> City-level:</td>
<td>
<select name= "" id= "" class= "" >
<option value= "" ></option>
</select>
</td>
<td> County/District:</td>
<td>
<select name= "" id= "" class= "three" >

<option value= "" ></option>

</select>
</td>

</tr>
</table>

//js Call Show1 show2 page

$ (document). On ("Change", ". One", function () {
var one=$ (this). Val ();
$.get (
"{: url (' login/two ')}?id=" +one,
function (data) {
$ ("."). HTML (data);
 }
 )
})

//Urban
$ (document). On ("Change", ".", Function () {
var two=$ (this). Val ();
$.get (
"{: url (' login/three ')}?id=" +two,
function (data) {
$ (". three"). HTML (data);
 }
 )
})

Show1 Show Level Two cities

<select name= "" id= "" class= "one" >
    <option value= "" > Please select </option>
    {volist name= "arr" id= "V"}
    <option value= "{$v. ID}" >{$v .name}</option>
    {/volist}
</select>

Show2 Show Level Three cities

<select name= "" id= "" class= "one" >
    <option value= "" > Please select </option>
    {volist name= "arr" id= "V"}
       <option value= "{$v. ID}" >{$v .name}</option>
    {/volist}
</select>

Second-level linkage