php - 在 PHP 中进行多次（查询）检查（优化）

Question

我想问一下，有什么方法可以缩短我的脚本

第一次检查，如果得到uid，做第二次和第三次检查

$result = mysqli_fetch_row(mysqli_query($con, "SELECT MAX(`uid`) FROM `pvpgn_bnet`"));
if($result) {
    Do Second and First Check();
}

第二次检查

$result = mysqli_fetch_row(mysqli_query($con, "SELECT * FROM `pvpgn_bnet` WHERE acct_email = '" . $email . "'"));
    if($result) {
        errorMsg();
    }

第三次检查

$result = mysqli_fetch_array(mysqli_query($con, "SELECT `uid` FROM `pvpgn_bnet` WHERE acct_username = '" . $username . "'"), MYSQLI_BOTH);
if($result) {
    errorMsg();
}

Answer 1

我不知道第一个过滤器的用途（它没有意义），但第二个和第三个可以组合。考虑这个例子：

$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
$stmt = $mysqli->prepare("SELECT * FROM pvpgn_bnet WHERE acct_email=? OR acct_username=?")
$stmt->bind_param("ss", $email, $username);
$stmt->execute();
// other processes

$res = $stmt->get_result();
while($row = $res->fetch_array(MYSQLI_ASSOC)) {
    // what ever you want to do here
}