Reading only specific lines of a database depending on the query name

On a simple website i have some articles that are stored inside my db with a button each which, when pressed, leads the reader to another site with the matching content.

I have two classes: on the first I connect to my database and return the result and in the other class where i read the contents of my db.
Now i want to read only specific lines from my db, when the $_GET["eintrag"] matches the value of the first column of each article so i don’t have to read through all my articles which would may slow down my code if there are a lot of articles:

I want to find the single rows inside the function "leseArtikel()" without reinstating a db connection and all the other variables from the "Datenbank" class

<?php 

class Datenbank {
    public $connection;
    public $query;
    public $result;

    public function __construct($servername, $dbusername, $dbpassword, $dbname) {
        $this->connection = mysqli_connect($servername, $dbusername, $dbpassword);
        mysqli_select_db($this->connection, $dbname);
    }

    public function getResult(){
        
        $query = "SELECT * FROM protokoll_artikel";
        $result = mysqli_query($this->connection,$query);
        
        return $result;    
    }
    
    public function close()
    {
        mysqli_close($this->connection);   
    }
}

class ProtokollEinträge{
    public function leseAlleArtikel(){
        
        $result = new Datenbank("localhost", "*******", "*******", "*******");
        $result = $result->getResult();
        
        if (mysqli_num_rows($result) > 0) { 
            // OUTPUT DATA OF EACH ROW 
            $row = array();
            
            while($row = mysqli_fetch_assoc($result)) {
                $weeks[$row["KW"]] = $row;  
            }                    
        }
        return $weeks;
    }

    public function leseArtikel($eintragsIds){

        $item = new ProtokollEinträge();
        $item = $item->leseAlleArtikel();
        if (!isset($item[$eintragsIds])){
            return false;
        }
        return $item[$eintragsIds];
    }
} ?>

This is the code where i want to implement only finding the matching line:

$eintragsIds = $_GET["eintrag"];
                    
                    
                    $item = new ProtokollEinträge;
                    $item = $item->leseArtikel($eintragsIds);
                    
                    // EIntrag existiert nicht
                    if ($item === false) {
                        echo nl2br("Dieser Artikel existiert nicht! \n
                        Bitte halten sie sich an die verlinkten Artikel auf der Startseite: \n")?>
                        <br><a href="https://djumla.dev/praktikum/protokoll.php">Startseite</a><?php
                    }
                    else {
                        
                    ?>
                    <div class="woche">
                        <h3><?php echo $item["KW"]; ?>:</h3> <h4><?php echo $item["TITEL"] ;?></h4><br>     
                        <p><?php echo $item["INHALT"];?><br></p><p><?php echo $item["TEXT"];?><br></p>
                        <br><a href="https://djumla.dev/praktikum/protokoll.php">Zurück zur Startseite</a> 
                    </div>
                                
                        
                    <?php  }?>
                  

                </section>    
            </main>
                     
            <aside>
                <section>
                    <div class="bild">
                        <img src="bilder/djumla.png"
                        class="avatar">
                    </div>  
                            
                    <h2>Kontakt</h2>
                    <p><img src="bilder/phone.png" width="30px" height="30px" > ********</p>
                    <p><img src="bilder/Vector.png" width="30px" height="20px"> ********</p>
                    <p><img src="bilder/map-pin.png" width="30px" height="30px"> ********</p>
                </section>

I tried using

$query = "SELECT * FROM protokoll_artikel WHERE KW =" .$eintragsIds; ?> 

where $eintragsIds = $_GET["eintrag"]

>Solution :

public function leseArtikel($eintragsIds) {
    $db = new Datenbank("localhost", "*******", "*******", "*******"); // Create single database connection

    $query = "SELECT * FROM protokoll_artikel WHERE KW = ?"; // Prepared statement with placeholder
    $stmt = mysqli_prepare($db->connection, $query); // Prepare the statement

    mysqli_stmt_bind_param($stmt, "i", $eintragsIds); // Bind the parameter

    mysqli_stmt_execute($stmt); // Execute the prepared statement

    $result = mysqli_stmt_get_result($stmt); // Get the result

    if (mysqli_num_rows($result) > 0) {
      $row = mysqli_fetch_assoc($result); // Fetch the single row
      return $row; // Return the single row as an associative array
    } else {
      return false; // Return false if no row is found
    }

    mysqli_stmt_close($stmt); // Close the prepared statement (recommended)
    $db->close(); // Close the database connection (if needed)
  }

Create a single instance of the Datenbank class within leseArtikel. This avoids redundant connections for each call.

$eintragsIds = $_GET["eintrag"];

$item = new ProtokollEinträge();
$artikel = $item->leseArtikel($eintragsIds);

if ($artikel === false) {
  // ... handle non-existent article
} else {
  // ... display article details using $artikel data
  echo "KW: " . $artikel["KW"];
  echo "TITEL: " . $artikel["TITEL"];
  // ... and so on
}