多条件动态筛选,该如何处理

$jg = array(1000, 2000, 3000);
$sj = array(2001, 2002, 2003);

if(isset($_GET['act'])) {
  $k = substr($_GET['act'], 3);
  unset($_GET['act']);
  if($k == 'all') $_GET = array();
  else unset($_GET[$k]);
}
  
echo '
价格：';
$param = getparam('jg');
foreach($jg as $v) echo " $v";

echo '
时间：';
$param = getparam('sj');
foreach($sj as $v) echo " $v";

$param = http_build_query($_GET);
echo "
清除价格 清除时间 全部清除";
echo "
select * from  tbl_name " . expr();

function getparam($k) {
  $param = $_GET;
  if(isset($_GET[$k])) unset($param[$k]);

  $param[$k] = '';
  return http_build_query($param);
}

function expr($expr='and') {
  if(! $_GET) return '';
  foreach($_GET as $k=>$v) $r[] = "$k='$v'";
  return 'where ' . join(" $expr ", $r);
}