Please help me filter by category in PHP?

Question

have 2 tables , the articles table and the table categorie_article in the database, what I want is the following, that appear all the names of registered categories (ex CATEGORIA1, categoria2, etc) and when clicking the category goes to a category.php file where it displays all the posts of the category I clicked, regardless of the category clicked goes in this document, could help me please look below the code I made only appears the name and ID of the category, based on it I complete the code and the category.php by kindness ? Cod below =

<?php
                    $result_categoria = "SELECT * FROM artigos WHERE sts_situacoe_id=1 ORDER BY id DESC LIMIT 6";
                    $resultado_categoria = mysqli_query($conn, $result_categoria);
                    ?>
                    <div class="p-3">
                        <h4>Categorias</h4>
                        <ol class="list-unstyled" data-categoria="comida">>

                            <?php
                            while($row_categoria = mysqli_fetch_assoc($resultado_categoria)){
                                echo "<li><a href='".pg."/artigo/".$row_categoria['id']."'>".$row_categoria['nome']."</a></li>";
                            }
                            ?>

                        </ol>
                    </div>

Answer 1

can resolve this issue by passing your category id via GET url, and in your category.php file, validate and take the GET value that would be the id of the category and perform a query in the articles table by taking all the articles in that category that I believe is your foreign key in the articles table.

In...

<?php
     while($row_categoria = mysqli_fetch_assoc($resultado_categoria)){
       echo "<li><a href='".pg."/artigo/".$row_categoria['id']."'>".$row_categoria['nome']."</a></li>";
     }
?>

Modify your href to pass the GET parameter this way...

echo "<li><a href='".pg."/artigo/categoria.php?categoria=".$row_categoria['id']."'>".$row_categoria['nome']."</a></li>";

That done you already have the possibility to validate this in the file, here I am considering that your query is performed in the file category.php, if this validation is performed in another file, The logic is the same, only needing to change the place where you will send the GET to validation. In the category.php file take the value of the parameter and query your table this way...

// verificar se o parâmetro GET existe e se não é vazio
if(isset($_GET['categoria']) && !empty($_GET['categoria'])){
   $id = $_GET['categoria'];
   //.... Query para realizar a consulta e listar os resultados
} else {
   //... parâmetro GET não foi setado ou é vazio, faça o que desejar como mostrar aviso ou redirecionar para outra página
}

That should solve your question simply. I hope I’ve helped, good studies!

EDITION:

Leticia, I will change a little the way you wrote yours, it is the same thing but in a different way of writing in html php, it left more readable and I realized that it is concatenating ". pg". in its condition, without the $symbol, this pg is a global constant? If it is, just take the $, follow the change...

<div class="p-3"> <h4>Categorias</h4> 
  <ol class="list-unstyled"> 
    <?php while($row_categoria = mysqli_fetch_assoc($resultado_categoria)): ?>
    <li><a href='<?php echo $pg; ?>/artigo/categoria.php?categoria=<?php echo $row_categoria['id'] ?>' ><?php echo $row_categoria['nome']; ?></a></li>
    <?php endwhile; ?>
  </ol>
<div>