<?php

$idcategorie = trim($_GET["idcategorie"]);
$motcle = trim($_GET["motcle"]);

// aucun mot clé => affichage de tous les résultats
                if ($motcle == "") { 
                    $sqlCount = " SELECT count(id_probleme)
                       FROM problemes
                       WHERE id_categorie = $idcategorie ";

                    $sqlDetail = " SELECT id_probleme, id_categorie, nom, solution
                       FROM problemes
                       WHERE id_categorie = $idcategorie";
                } else { // mot clé saisi => recherche
                    $arrMotcle = explode(" ",$motcle);
                    $strMotCle = ""; $separateur = "";
                    foreach ($arrMotcle as $itemMotcle) {
                        $strMotCle = $strMotCle . $separateur . " nom LIKE \"%".$itemMotcle."%\" OR solution LIKE \"%".$itemMotcle."%\" ";
                        $separateur = " OR ";
                    }
                  

                    $sqlDetail = " SELECT id_probleme, id_categorie, nom, solution
                       FROM problemes
                       WHERE id_categorie = $idcategorie
                       AND (".utf8_decode($strMotCle).") ";
                       //die($sqlDetail);
                }

?>

//voilà mon formulaire
    <div class="container">
        <form class="navbar-form navbar-left" role="search">

          <div class="form-group">
                <input type="text" name="motCle" class="form-control" placeholder="Rechercher">
          </div>
          <button type="submit" class="btn btn-default">Envoyer</button>
        </form>
    </div>

SELECT   id, nom, solution
FROM	 problemes
WHERE    (nom LIKE '%soucis%' or solution LIKE '%soucis%')
AND 	 (nom LIKE '%logiciel%' or solution LIKE '%logiciel%')