Admin for Country, State and City Linked Dropdown Data

The admin side manages Country, State and City data used by the three linked dropdowns. State-changing operations should use POST, validate parent IDs, and use prepared INSERT/DELETE queries.

Add a Country Top ↑

$.post(
    "admin-add-country.php",
    {
        name:
            $( "#country_name" )
                .val()
                .trim()
    },
    null,
    "json"
);

Add a State Top ↑

$.post(
    "admin-add-state.php",
    {
        country_id:
            $( "#country" ).val(),
        name:
            $( "#state_name" )
                .val()
                .trim()
    },
    null,
    "json"
);

Add a City Top ↑

$.post(
    "admin-add-city.php",
    {
        state_id:
            $( "#state" ).val(),
        name:
            $( "#city_name" )
                .val()
                .trim()
    },
    null,
    "json"
);

Delete Records Top ↑

$stmt = $dbo->prepare(
    'DELETE FROM city
     WHERE id = :id'
);

$stmt->execute([
    'id' => $id
]);

See SQL DELETE and PDO connection.

Original Admin Demos Top ↑

Download project

Protect admin pages with authentication/authorization and CSRF defenses before exposing them publicly.

Original Source Examples Retained for Migration Reference Top ↑

These source-page examples are retained so no learner-purpose example is silently lost. Use the modern examples above as the recommended implementation.

Original example 1

<?Php
require "config.php";// connection details
error_reporting(0);//no error reporting 

///////////////

$country_code=$_POST['country_code'];// Country code
$country=$_POST['country'];

///////////// Validate the inputs ////////////

if(strlen($country_code) > 0 and strlen($country)>0){

$sql=$dbo->prepare("insert into plus2_country (country,country_code) values(:country,:country_code)");
$sql->bindParam(':country',$country,PDO::PARAM_STR,25);
$sql->bindParam(':country_code',$country_code,PDO::PARAM_STR,4);
if($sql->execute()){
$state_id=$dbo->lastInsertId(); 
$msg= " Country  Added : $country : code = $country_code ";
}
else{
$msg = " Database Problem  Not able to add data please contact Admin ";
}
$("#f1")[0].reset();
}else{
$msg=" Enter  Country and Country Code";
}

echo $msg;
?>

Original example 2

<script>
$(document).ready(function() {
///////////////////////////
$("#b1").click(function(){
$("#msg").html('Just Wait ...'); 
$("#msg").show();

$.post( "dropdown3-admin-add-countryck.php", {"country_code":$('#country_code').val(),"country":$('#country').val()},function(return_data,status){
$("#msg").html(return_data.msg); 
setTimeout(function() { $("#msg").hide(); }, 2000);
if(return_data.db_status=='OK'){
 window.location = "dropdown3-admin-add-country.php";
}
},'json');
});
////////////////////////////
})
</script>

Original example 3

if(strlen($country_code) > 0 and strlen($state)>0){

$sql=$dbo->prepare("insert into plus2_state (state,country_code) values(:state,:country_code)");
$sql->bindParam(':state',$state,PDO::PARAM_STR,25);
$sql->bindParam(':country_code',$country_code,PDO::PARAM_STR,4);
if($sql->execute()){
$state_id=$dbo->lastInsertId(); 
$msg= " State   Added : $state : State_id = $state_id";
}
else{
$msg = " Database Problem  Not able to add data please contact Admin ";
}
}else{
$msg=" Select   Country and enter state name";
}

echo $msg;

Original example 4

<script>
$(document).ready(function() {
$("#b1").prop('disabled',true);
$("#t1").prop("disabled", true);
////////////////////////////////////
$("#country_code").change(function(){ // change function of listbox
$("#b1").prop('disabled',false);
$("#t1").prop("disabled",false);

});
///////////////////////////
////////////////////////////////////
///////////////////////////
$("#b1").click(function(){
$("#msg").html('Just Wait ...'); 
$("#msg").show();

$.post( "dropdown3-admin-add-stateck.php", {"country_code":$('#country_code').val(),"state":$('#t1').val()},function(return_data,status){
$("#f1")[0].reset();

$("#msg").html(return_data); 
setTimeout(function() { $("#msg").hide(); }, 2000);

});
});
////////////////////////////
})
</script>

Original example 5

if(strlen($state_id) > 0 and strlen($city) > 1){

$sql=$dbo->prepare("insert into plus2_city (city,state_id) values(:city,:state_id)");
$sql->bindParam(':city',$city,PDO::PARAM_STR,25);
$sql->bindParam(':state_id',$state_id,PDO::PARAM_INT,4);
if($sql->execute()){
$city_id=$dbo->lastInsertId(); 
$msg= " City Added : $city : id = $city_id ";
}
else{
$msg = " Database Problem  Not able to add data please contact Admin ";
}
}else{
$msg=" Enter all details ";
}
echo $msg;

Original example 6

<script>
$(document).ready(function() {
$("#b1").prop('disabled',true);
$("#t1").prop("disabled", true);
////////////////////////////////////
$("#country_code").change(function(){//change function of listbox
$("#state_id,#city_id").empty();
$("#b1").prop('disabled',true);
$.post( "dropdown3ck.php", {"country_code":
$('#country_code').val()},function(return_data,status){
$("#state_id").append("<option value=''>Select One</option>");

$.each(return_data.state, function(key,value){
$("#state_id").append("<option value=" + value.state_id +">"
+value.state_id + ':' + value.state+"</option>");
});

},"json");

});
///////////////////////////
////////////////////////////////////
$("#state_id").change(function(){//change function of listbox
if ($( "#country_code" ).val().length >0 && 
$( "#state_id" ).val().length >0 ){
$("#b1").prop('disabled',false);
$("#t1").prop("disabled", false);
}
});
///////////////////////////
$("#b1").click(function(){
$("#msg").html('Just Wait ...'); 
$("#msg").show();

$.post( "dropdown3-admin-add-cityck.php", 
{"state_id":$('#state_id').val(),"city":$('#t1').val()},
function(return_data,status){
$("#msg").html(return_data); 
setTimeout(function() { $("#msg").hide(); }, 2000);
$("#f1")[0].reset();
$("#t1").attr('value','');
});
});
////////////////////////////
})
</script>

Original example 7

DELETE FROM plus2_city  WHERE city_id=:city_id

Original example 8

DELETE FROM plus2_state,plus2_city using plus2_state 
INNER JOIN plus2_city 
WHERE plus2_state.state_id=plus2_city.state_id 
AND plus2_state.state_id=:state_id

Original example 9

DELETE  FROM plus2_country,plus2_state,plus2_city USING plus2_state
 INNER JOIN plus2_city 
 INNER JOIN plus2_country 
 WHERE plus2_country.country_code=plus2_state.country_code 
 AND plus2_state.state_id=plus2_city.state_id 
 AND  plus2_country.country_code=:country_code

Additional Original Learning Routes Top ↑

listbox.php

Continue Learning jQuery

jQuery Tutorial Home jQuery Basic Structure Functions Used with jQuery jQuery Events jQuery Effects jQuery UI jQuery Exercises

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

About the author Watch on YouTube

Connect: