php - Apply where condition on same column many times -

i have catalog page on products getting displayed via ajax. code ajax call below:

function updateproducts(opts){

$.ajax({   type: "post",   url: "func.php",   datatype : 'json',   cache: false,   data: {filteropts: opts},   success: function(records){     $('#slider').html(makeprodiv(records));    } }); 

}

and func.php has code below:

$pdo = new pdo('mysql:host=localhost;dbname=filter', 'root', '');   $select = 'select id, pname, prate, pdesc';  $from = ' product';  $where = ' true';    $opts = isset($_post['filteropts'])? $_post['filteropts'] : array('');    if (in_array("shoes", $opts)) { $where .= " , ptype = 'shoes'"; }   if (in_array("belt", $opts))  { $where .= " , ptype = 'belt'"; }     $sql = $select . $from . $where;    $statement = $pdo->prepare($sql);    $statement->execute();    $results = $statement->fetchall(pdo::fetch_assoc);    $json = json_encode($results);    echo($json); 

the problem facing are:

when select both belt , shoes in filter no result getting displayed because query turns out below on selecting both options:

select id, pname, prate, pdesc product true , ptype = 'shoes'  , ptype = 'belt' 

please let me know how achieve single product check working fine.

indeed query return nothing have 2 conflicting conditions. resolve this, should replace this:

$opts = isset($_post['filteropts'])? $_post['filteropts'] : array('');  if (in_array("shoes", $opts)) { $where .= " , ptype = 'shoes'"; } if (in_array("belt", $opts))  { $where .= " , ptype = 'belt'"; } 

by (notice change @ end of first line also):

$opts = isset($_post['filteropts'])? $_post['filteropts'] : array(); if(count($opts)){     $where .= " , ptype in (". str_pad('',count($opts)*2-1,'?,') .")"; } 

this produces clause this:

and ptype in (?,?) 

then pass $opts value argument execute. safe sql injection, don't need verify values in predefined list:

$statement->execute($opts); 

this way don't need adapt code when have other types can selected.