PDO / OOP搜索引擎php

Question

I can't seem to place what is wrong in the code :

This is where the function takes place and execute. this is from a different file

public function search($title, $table)
    {

        $q = "SELECT * FROM $table WHERE (':title' LIKE '%".$title."%')";
        $stmt = $this->con->prepare($q);
        $stmt->execute(array(':title' => $title));
        $result = $stmt->fetchAll(PDO::FETCH_ASSOC);
        return $result;
    }

This part should check and results. different file again

 if(isset($_POST['submit'])){
     $search = $_POST['search'];   
     $min_length = 2;

    if(strlen($search) >= $min_length){

        $search = htmlspecialchars($search); 
        $results = $code->search($title, "book_info"); //the error is here*

        if(mysql_num_rows($results) > 0){ // the error is here too**

            while($results != $code->fetchAll()){
            echo "<table id=\"tablecolor\" class=\"echoname\" >";
            echo "<th><b>ID</b></th>";
            echo "<th><b>Title</b></th>";
            echo "<th><b>Author</b></th>";
            echo "<th><b>ISBN</b></th>";
            echo "<th><b>Publisher</b></th>";
            echo "<th><b>Language</b></th>";
            echo "<th><b>Genre</b></th>";
            echo "<th><b>Quantity</b></th>";
            echo "<pre>";  
                    echo "<tr>";
                    echo "<td>".$id."</td>";
                    echo "<td>".$title."</td>";
                    echo "<td>".$author."</td>";
                    echo "<td>".$isbn."</td>";
                    echo "<td>".$publisher."</td>";
                    echo "<td>".$language."</td>";
                    echo "<td>".$genre."</td>";
                    echo "<td><center>".$quantity."</center></td>";
                    echo "</tr>";    
            echo "</pre>";
            echo "</table>";

            }

        }
        else{ 
            echo "No results";
        }

    }
    else{ 
        echo "Minimum length is ".$min_length;
    }
}

This is the error when executed

*Notice: Undefined variable: title in C:\wamp\www\unitato\web\user\user-search1.php on line 16
**Warning: mysql_num_rows() expects parameter 1 to be resource, array given in C:\wamp\www\unitato\web\user\user-search1.php on line 18

I want to know how to fix this error.

Answer 1

You are doing two things wrong:

• First: You are trying to use mysql_fetch_rows() when you are using PDO. One is for mysql other is for PDO. So, They are two completely different constructs, so don't mix them up.

• Second: You are assuming all SELECT statement is going to return some value, by simply doing fetchAll afterwards.

  *What if the query was not successful ? How can fetchAll() get you anything?

If you want to check your SELECT statement is returning any value you can do this from the function using rowCount() method.

public function search($title, $table)
{
        try{
        $q = "SELECT * FROM $table WHERE title LIKE ?";
        $stmt = $this->con->prepare($q);
        $stmt->execute(array("%$title%");
        }catch(PDOException $e){
         throw new Exception("ERROR:". $e->getMessage()); 
        }
        if(!$stmt->rowCount()){
          return false; #this will return false if data isn't found. 
        }
        $result = $stmt->fetchAll(PDO::FETCH_ASSOC);
        return $result;
}

Or instead of mysql_fetch_rows outside you function you can check do:

$results = $code->search($title, "book_info");
if($result){
 //query is ok
}