php - PHP中的PDO，如何改进这个PDO mysql代码

Question

感谢检查。所有有用的答案/评论都已投票。我有以下代码，可以完成工作，但 imo 效率不高。我认为它效率不高的原因是因为我使用的是 fetchAll + 循环即使我知道查询将返回 1 条记录或没有记录。

//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
}

我如何改进它以消除 foreach 和 fetchAll 的笨重外观(考虑到我知道它总是只有 1 条或 0 条记录)？但我仍然需要类似的检查点，以便我可以执行相同的 BLOCK A BLOCK B BLOCK C 作为我当前的逻辑需要它。

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
}