PHP中的PDO,如何改进这个PDO mysql代码

Question

谢谢你检查.所有有用的答案/评论都已经过投票.我有以下代码,它完成了这项工作,但是imo效率不高.我认为它不高效的原因是因为我使用fetchAll +循环,即使我知道查询将返回1或没有记录.

//assume the usual new PDO, binding, and execute are up here

$myval = "somevalue";

$res = $stmt->fetchAll(PDO::FETCH_ASSOC);

if (!$res) {
    //no record matches
    //BLOCK A CODE HERE
} else { 
    //found matching record (but always going to be 1 record, no more)  
    foreach($res as $row) {
        if ($myval == $row['val']){
            //myval is the same as db
            //BLOCK B CODE HERE
        } else {
            //myval is different from db
            //BLOCK C CODE HERE
        }
    }//foreach
}

如何改进它以消除foreach和fetchAll的庞大外观(考虑到我知道它总是只有1或0记录)？但是我仍然需要类似的检查点,所以我可以BLOCK A BLOCK B BLOCK C按照我当前的逻辑需要执行相同的操作.

Answer 1

$myval = "somevalue";

$row = $stmt->fetch(PDO::FETCH_ASSOC);

if (!$row) {
    //no record matches
    //BLOCK A CODE HERE
} else if ($myval == $row['val']) { 
    //myval is the same as db
    //BLOCK B CODE HERE
} else {
    //myval is different from db
    //BLOCK C CODE HERE
}