如果字段为空，则返回所有结果

Question

I'm working at a search script at the moment, but I have a little problem. I'm using the following query:

mysql_query("SELECT * FROM boeken WHERE 
             titel LIKE '%".$titel."%' AND 
             categorie_id = '".$categorie."' AND 
             auteurs LIKE '%".$auteurs."%' AND 
             jaar_copyright = '".$jaar_copyright."' 
             AND ontwerp_groep = '".$ontwerp_groep."'");

For example, when I search for 'categorie_id' = '5', and leave the other fiels empty, I want to get every row that has categorie_id = 5. No matter what the other fields are.

What it does is the following: I get every row that has categorie_id = 5, but where the title is empty, where the 'jaar_copyright' is empty, etc. etc.

How can I fix this the way I want?

Answer 1

<?php

    $query = "SELECT * FROM boeken WHERE";
    $n = 0;
    $makeAnd = "";

    foreach($_POST as $key=>$value){
        if($value != '' && $value != 'submit'){
            if($n != 0){$makeAnd = " AND";}
            if(!is_numeric($value)){
            $query .= "$makeAnd `$key` LIKE '%$value%'";
        } else {
            $query .= "$makeAnd `$key` = '$value'";
        }
            $n++;
        }

    }

    print $query;


?>

In this way you can filter out empty values. If other values are posted to $_POST make sure to filter them out in the "if($value !=" part.