Question

我正在开发一个php项目，客户可以在这个项目中喜欢和不同于某个帖子。 mysql数据库中的clomn应该增加或减少1，即（+1或-1）下面是我的sql语法我不知道哪里出错了请帮忙。

$time = date("Y-m-d H:i:s");
$sql_likes2 = "UPDATE `tble_likes` SET likes = `tble_likes`.`likes`-1 WHERE `tble_likes`.`postaID` = ? AND `tble_likes`.`useremail` = ?";
$SQL_statement_likes= $this->conn->prepare($sql_likes2);
$SQL_statement_likes->bindParam(1,$this->posta2);
$SQL_statement_likes->bindParam(2,$this->user_mail);
$SQL_statement_likes->execute();
if($SQL_statement_likes==true){
    echo $this->user_mail;
    $sql_countL = "SELECT COUNT(likes) AS SUM FROM tble_likes WHERE  postaID=? GROUP BY postaID LIMIT 1";
    $sql_statement_countL = $this->conn->prepare($sql_countL);
    $sql_statement_countL->bindParam(1,$this->posta);
    $sql_statement_countL->execute();
    if($sql_statement_countL==true){
        $row=$sql_statement_countL->fetch();
        $unlike = $row[0];
        echo $unlike;
    }
}

Answer 1

SUM是保留字，所以

 $sql_countL = "SELECT COUNT(likes) AS sumRows FROM tble_likes WHERE  postaID=? GROUP BY postaID LIMIT 1";

sql语句不适合我

1 个答案: