php - 如何将查询结果插入php中的数组并在另一个数组中检查它们

Question

我在 mysql 数据库中有律师、律师徽章、徽章表。我想将徽章中的所有徽章 ID 加载到一个数组中。(allBadges[])。我想将律师的所有徽章 ID 加载到另一个数组(lawyerBadges[]).然后我想检查allBadges元素是否在lawyerBades中。如何做。

这是我到目前为止的代码。

    $username = $_SESSION['username'];

    getPoints();


    function getPoints(){
        global  $connection;
        global $username;
        $pointCount_query =mysqli_query( $connection,"SELECT * FROM lawyer WHERE username='".$username."'");
        $pointCount=mysqli_fetch_array($pointCount_query);
        $points= (int)$pointCount['points'];

        addBadges($points);

    }

    function addBadges($user_points){
        global  $connection;
        global $username;
        $badge_array = array();
        $badgeList=mysqli_query($connection,"SELECT bId FROM badge ");
        $badges=mysqli_fetch_array($badgeList);

        $lawyers_badges=mysqli_query($connection,"SELECT bID FROM lawyerbadge WHERE username='".$username."'");
        while($row=mysqli_fetch_assoc($lawyers_badges)){
            $badge_array[]=$row;
        }

        //this is the problem area
       foreach( $badge_array  as $value){
            echo $value.'<br />';

        }


    }

Answer 1

您需要 2 个 for 循环。外循环将遍历所有徽章。内循环将遍历所有律师徽章。如果没有找到外循环徽章，它将回显徽章

foreach( $badgeList as $badge){
    $badge_found_flag = false;
    foreach( $badge_array  as $lawyerBadge){
        $badge_found_flag = true;

    }
    if($badge_found_flag == false){
        echo $badge.'<br />';
    }
}

更新

更好的替代方法是使用 LEFT JOIN，它不需要手动循环并且只需要一个查询就可以得到结果。

SELECT badge.bId FROM badge 
LEFT JOIN lawyerbadge  ON badge.bId = lawyerbadge.bID
WHERE username = '$username'"
AND lawyerbadge.bID IS NULL;

这将只返回您感兴趣的徽章。