Results UNDEFINED in SQL query and php -

i new when comes php, sql , still learning, trying last 4 string value of column value telephone numbers: (7258787) trying display last 4 string search query full 7 string (8787) base on have read substring(column_name, -4) result last 4 strings right. codes returns undefined, can enlighten me this?

    if (isset($_get['telephone'])) {     $data = "%".$_get['telephone']."%";     $sql = 'select telephone, substring(telephone,-4)from employee'; 

using this:

   $sql = 'select * employee telephone ?'; 

will result correct value of 7258787 result whole string(telephone numbers) type on search box

thank in advance

this whole code:

this not answer whole script, (credits israel barragan) in database have employee table , columns 'id', 'name', 'telephone', , 'email'

<?php  header('content-type: application/json'); require_once 'connectiondb.php'; $conn = dbconnect(); $ok = true; // use verify status of update.  if (isset($_get['telephone'])) {     // create query     $data = "%".$_get['telephone']."%";     $sql = 'select * employee telephone ?';     // have tell pdo going send values query     $stmt = $conn->prepare($sql);     // execute query passing array toe execute();     $results = $stmt->execute(array($data));     // extract values $result     $rows = $stmt->fetchall();     $error = $stmt->errorinfo();     //echo $error[2]; } // if there no records. if(empty($rows)) {     echo json_encode( array('error'=>'there not records','0'=> 'there            not records')); } else {     echo json_encode($rows); } ?> 

sorry new stackoverflow,

you can bind result in query, , last 4 digits display.

for instance, can this

(not aren't binding parameters. need this)

$stmt->bind_param("s", $data); 

and execute this:

$stmt->execute(); 

in query instead of using select *, name specific keys , can bind result (assuming need phone number:

$stmt->bind_result($telephone); 

then result so:

$stmt->fetch(); 

then can substring off of $telephone (in php substr())

echo substr($telephone,-4); 

(oh yeah , don't forget close object with

$stmt->close(); 

after done)

edit:
here's query put substring

$data = "%".$_get['telephone']."%"; $stmt = $conn->prepare("select telephone employee telephone ?"); $stmt->bind_param("s", $data); $stmt->execute(); $stmt->bind_result($telephone); $stmt->fetch(); echo substr($telephone,-4); $stmt->close();