我正在尝试从数据库中提取数据，该数据将从数据库中的两个不同表中提取，错误在$ returns = mysql_query中

Question

I'm trying to pull data from two different tables in the database and I keep on having error. when I run the code it displays nothing

Here is my code:

<?php 
$st="";
$sc="";

    if (isset($_POST['submit']) && $_POST['submit'] == "submit"){
       $st=$_POST['s-t'];
       $sc= "WHERE nums like \"%$st%\"  or d_n like \"%st%\" ";
    }


    if (isset ($_GET['look']) && $_GET ['look'] != "") {
       $st=$_GET['look'];
       $sc = "WHERE nums like \"%$st%\"  or d_n like \"%st%\" ";
     }

    $db = mysql_db_connect();
    $rpp = 50;

    if (isset($_GET['page'])){

    $pn = $_GET['page'];
    $begin = ($rpp*$pn)-$rpp;
    $finish=($rpp*$pn);
    $finish=50;
} 
else {
    $pn =1;
    $begin = 0;
    $finish =$rpp;
} 

    $returns = mysql_query ("SELECT * FROM  extenz $sc", $db);
    $numer_rows = mysql_num_rows($returns);
    $number_pages = ((int) ($numer_rows/$rpp)) +1;

    if (($number_rows % rpp) ==0){
    $number_pages=$number_pages -1;
}
$returns = mysql_query("SELECT nums, name , p_m FROM extenz, P_exten  left join p_exten on extenz $sc order by nums & P_m LIMIT $begin, $finish", $db);

?> 

Answer 1

i answered my question

the error was in the following line of code

$returns = mysql_query("SELECT nums, name , p_m FROM extenz, P_exten  left join p_exten on extenz $sc order by nums & P_m LIMIT $begin, $finish", $db);

and the correction was

$returns = mysql_query("SELECT extenz.nums, extenz.name,p_exten.P_M FROM extenz LEFT JOIN ON  p_exten.extenz=extenz.nums $sc ORDER BY nums LIMIT $begin, $finish",$db);