有没有人知道为什么以下mysqli_num_rows在没有结果时没有返回零?而不是显示' 0'它根本不显示任何内容。完全莫名其妙。编辑<< msqli_num_rows工作正常并在有结果时显示一个数字,当没有任何结果时它就不是......
$result = mysqli_query($con,"
SELECT LastName
AS sLast, FirstName
AS sFirst
FROM students
LEFT JOIN
(SELECT id, name
FROM employers)
a ON a.id = $e_id
WHERE WK1 = a.name");
while($row = mysqli_fetch_array($result)) {
$wk1 = mysqli_num_rows($result);
echo $row['sLast'] .", ".$row['sFirst']."<br>";
}
答案 0 :(得分:3)
如果没有行,则无法获取任何内容,因此您的循环永远不会运行。首先尝试获取num_rows。
$wk1 = mysqli_num_rows($result);
while($row = mysqli_fetch_array($result)) {
echo $row['sLast'] .", ".$row['sFirst']."<br>";
}
答案 1 :(得分:-1)