mysql - Do PDO (non-emulated) statements keep track of earlier statements?

Question

In other words, are the scenarios different performance-wise?

A:

for($i = 0; $i < 10; $i++)
{
    $pdo->prepare("SELECT :foo;")->execute(['foo' => 'test']);
}

B:

$sth    = $pdo->prepare("SELECT :foo;");

for($i = 0; $i < 10; $i++)
{
    $sth->execute(['foo' => 'test']);
}

Answer 1

不，pdo 没有这样的缓存机制，在场景 A 中，您每次都在创建 pdo 语句。