MySQL多条件

I am trying to search my database, I initially had it working with only one and condition but now with four, it will just refresh the page, removing field inputs.

I have tried using only a comma's but this appears to also not work. I have been unable to find any information on Google about their being a limit but also no examples using four conditions. Is there a correct or better way I could try?

if(isset($_POST['search'])){
   $lname = trim($_POST['lname']);
   $address = trim($_POST['address']);
   $street = trim($_POST['street']);
   $city = trim($_POST['city']);
   $county = trim($_POST['county']);

   if($lname==""){
      $error[] = "Provide Last Name."; 
   }elseif($address=""){
       $error[] = "Provide House Number/Name.";
   }elseif($street==""){
      $error[] = "Provide Street.";
   }elseif($city==""){
       $error[] = "Provide City.";
   }elseif($county==""){
       $error[] = "Provide County.";
   }else{
       try{
           $stmt = $conn->prepare("SELECT * FROM clients WHERE lname=lname AND address=address AND street=street AND city=city AND county=county");
           $stmt->execute(array("lname"=>$lname, "address"=>$address, "street"=>$street, "city"=>$city, "county"=>$county));
           $userRow=$stmt->fetch(PDO::FETCH_ASSOC);

           if($userRow==''){
               $user->redirect('./results.php?new='.$lname.$street);
           }else{
               if($userRow['rating'] == 'good'){
                   $user->redirect('./results.php?good='.$lname.$street);
               }
               if($userRow['rating'] == 'cautionextra'){
                   $user->redirect('./results.php?cautionextra='.$lname.$street);
               }
                if($userRow['rating'] == 'cautiondiscount'){
                   $user->redirect('./results.php?cautiondiscount='.$lname.$street);
               }
               if($userRow['rating'] == 'cautionlate'){
                   $user->redirect('./results.php?cautionlate='.$lname.$street);
               }
               if($userRow['rating'] == 'badnopay'){
                   $user->redirect('./results.php?badnopay='.$lname.$street);
               }
               if($userRow['rating'] == 'badabusive'){
                   $user->redirect('./results.php?badabusive='.$lname.$street);
               }
           }
        }
        catch(PDOException $e){
             echo $e->getMessage();
        }
    } 
}

Executing SELECT * FROM clients WHERE lname=lname AND address=address AND street=street AND city=city AND county=countyin phpmyadmin returns all of the rows, great but when I var_dump($userRow);, it shows the results for a row different to the one of which I tried to search for.

The issue is that using an equality test for the search columns makes it difficult to get a match with any row because:

• the entered values must match exactly to the column in the table row.
• all the search columns must be entered. If they are empty then they will never match any row.

The approach with search fields is:

• try to approximately match the input value with column value by using like instead of = as the comparison operator.
• make an empty input value match any column value. i.e. ignore the test

The supplied code will generate code: column like % for empty input or will wrap the input value in wildcards: column like %input value%

Untested source at Pastebin.com

Untested code:

<?php // completely untested code...
    $stmt = $conn->prepare("SELECT *
                           FROM clients
                           WHERE  lname   like :lname
                            AND   address like :address
                            AND   street  like :street
                            AND   city    like :city
                            AND   county  like :county");

    $stmt->execute(array("lname"  => empty($lname) ? '%' : '%'. $lname .'%',
                         "address" => empty($address) ? '%' : '%'. $address .'%',
                         "street"  => empty($street) ? '%' : '%'. $street .'%',
                         "city"    => empty($city) ? '%' : '%'. $city .'%',
                         "county"  => empty($county) ? '%' : '%'. $county .'%'));

    $userRow = $stmt->fetch(PDO::FETCH_ASSOC);

You don't need: ":lname" in execute(array(...)) just use index without colon in front: "lname".

Full line:

$stmt->execute(array("lname"=>$lname, "address"=>$address, "street"=>$street, "city"=>$city, "county"=>$county));