Php 设置if-else语句PDO

如何在PDO中设置IF-ELSE条件

如果有face='N'的记录，我希望能够回显结果。或回显“空”

$query = $db->prepare('SELECT student, subject FROM my_db WHERE faced = ? ORDER BY RAND() LIMIT 1');
$array = array('N');
$query->execute($array);
if ($query>0){
$result = $query->fetchAll(PDO::FETCH_ASSOC);
var_dump($result);
} else {
    echo 'Empty';
}

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您可以在检查之前执行提取：

$query->execute($array);
$result = $query->fetchAll(PDO::FETCH_ASSOC);
if (count($result) > 0){
    var_dump($result);
} else {
    echo 'Empty';
}

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给你！通过查询执行此操作：

SELECT 
Student,
Subject,
Max(CASE When faced ='N' then faced else 'Empty' End) as Faced
FROM my_db 
group by student

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@纳塔利听到这个消息真高兴！如果这一切都对你有用，请随意将答案标记为已接受！