CREATE EVENT 语句不适用于 PDO？ [复制]

Question

我似乎终其一生都无法弄清楚为什么这个 CREATE EVENT 语句不起作用。我可以从 CLI 将它的等价物直接放入 MariaDB，但由于某种原因，这个不起作用。

echo "unspaced, nexttime, ident, ttime<br />";

var_dump ($unspaced, $nexttime, $ident, $ttime);
echo "<br />";

$neweventstatement = $loginconn->prepare("CREATE EVENT :eventname ON SCHEDULE AT CURRENT_TIMESTAMP + :nexttime SECOND DO BEGIN UPDATE `tasks` SET ended = NULL WHERE id = :id AND created = :tasktime; END");
$neweventstatement->bindParam(':eventname', $unspaced, PDO::PARAM_STR);
$neweventstatement->bindParam(':nexttime', $nexttime, PDO::PARAM_INT);
$neweventstatement->bindParam(':id', $ident, PDO::PARAM_INT);
$neweventstatement->bindParam(':tasktime', $ttime, PDO::PARAM_STR);
$neweventstatement->execute();

产生以下输出：

unspaced, nexttime, ident, ttime
string(31) "t682020101400334320201014235504" int(300) int(68) string(19) "2020-10-14 00:33:43"

Error: SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '? ON SCHEDULE AT CURRENT_TIMESTAMP + ? SECOND DO BEGIN UPDATE tasks SET ended = NULL' at line 1

我也尝试过明显的变体，例如

CREATE EVENT :eventname ON SCHEDULE AT CURRENT_TIMESTAMP + :nexttime SECONDS DO BEGIN UPDATE `tasks` SET ended = NULL WHERE id = :id AND created = :tasktime; END
CREATE EVENT :eventname ON SCHEDULE AT CURRENT_TIMESTAMP + :nexttime SECOND DO UPDATE `tasks` SET ended = NULL WHERE id = :id AND created = :tasktime;
CREATE EVENT :eventname ON SCHEDULE AT CURRENT_TIMESTAMP + :nexttime SECOND DO BEGIN UPDATE `tasks` SET ended = NULL WHERE id = :id AND created = :tasktime; END
DELIMITER ^^ CREATE EVENT :eventname ON SCHEDULE AT CURRENT_TIMESTAMP + :nexttime SECOND DO BEGIN UPDATE `tasks` SET ended = NULL WHERE id = :id AND created = :tasktime; END ^^

但似乎没有任何效果。

我觉得我错过了一些明显的东西，但我看不到它。

编辑：出于某种原因，一个粗心大意的人将此标记为“为什么我准备的声明不会使用表名”的重复项。它不是。我已经对其进行了编辑，以明确问题所在。如下所述，问题是 CREATE EVENT 不能是准备好的语句。

Answer 1

mysql 手册中关于prepared statements 的部分包含您在准备好的语句中使用的SQL 语句列表。 CREATE EVENT 语句不包含在此列表中，因此您不能将其用作准备好的语句。

您必须通过字符串连接创建 sql 语句并照此执行。您必须添加进一步检查以确保这不会导致 sql 注入漏洞。