pdo SET变量

Question

我在使用PDO / MySQL，php 7.0和mysql 5.5按月获取累计金额时遇到一些问题。

通过多个查询，我收到了“ 百分比：SQLSTATE [HY000]：常规errorvar ”作为错误。如果我删除了这些“ SET”行，它就会消失，但是我无法做我想做的事情。

$sql = "
SET @accInc := 0;
SET @accOut := 0;
SELECT
q1.y as year,
q1.m as month,
(@accInc := @accInc + q1.income) AS accInc,
(@accOut := @accOut + q1.outgo) AS outInc
FROM
    (SELECT
    YEAR(`date`) AS y,
    MONTH(`date`) AS m,
    SUM(CASE WHEN amount > 0 THEN amount ELSE 0 END) as income,
    SUM(CASE WHEN amount < 0 THEN amount ELSE 0 END) as outgo
    FROM `transaction`
    GROUP BY y, m
    ORDER BY y, m
    ) AS q1";
require("./pdo.php");
try {
    $req = $db->prepare($sql);
    $req->execute();
    $data = $req->fetchAll(PDO::FETCH_ASSOC);
    foreach($data as $row) {
        $acc[$row["year"]][$row["month"]] = array(
            "inc" => (float)$row["accInt"],
            "out" => (float)$row["accOut"]
        );
    }
} catch(PDOException $except) {
    printf("Excention : %s", $except->getMessage());
}

谢谢。

编辑：我必须设置$db->setAttribute(PDO::ATTR_EMULATE_PREPARES, false); 并隔离SET命令。现在可以了。