php - 如何从查询 PHP 返回 COUNT(*) 结果

Question

public function votesThisMonth()
{
    $this->query = $this->pdo->prepare
    ("
        SELECT
            COUNT(*) AS num_votes
        FROM
            votes
        WHERE
            YEAR(year) = YEAR(CURRENT_DATE)
        AND MONTH(month) = MONTH(CURRENT_DATE)
    ");
    $result = $this->query->execute();

    return $result['num_votes'];
}

我想返回 2013 年和第 5 个月的所有行。但是当我有 10 多行具有相同数据时它返回“1”？

我做错什么了？

这些是位于我的数据库中的行：

id  ip          year    month
1   127.0.0.1   2013    5
2   127.0.0.1   2013    5
3   127.0.0.1   2013    5
4   127.0.0.1   2013    5
5   127.0.0.1   2013    5
6   127.0.0.1   2013    5
7   127.0.0.1   2013    5
8   127.0.0.1   2013    5
9   127.0.0.1   2013    5
10  127.0.0.1   2013    5
11  127.0.0.1   2013    5
12  127.0.0.1   2013    5
13  127.0.0.1   2013    5
14  127.0.0.1   2013    5
15  127.0.0.1   2013    5

编辑我的方法请看：

    public function votesThisMonth()
    {
        $this->query = $this->pdo->prepare
        ("
            SELECT
                *
            FROM
                votes
            WHERE
                YEAR(year) = YEAR(CURRENT_DATE)
            AND MONTH(month) = MONTH(CURRENT_DATE)
        ");
        $this->query->execute();

        return $this->query->rowCount();
    }

这返回'0'，为什么？

Answer 1

查询应该是

SELECT * FROM votes
WHERE `year`  = YEAR(CURRENT_DATE)
  AND `month` = MONTH(CURRENT_DATE) 

Answer 2

year并且month是关键字，不管大小写，所以用反引号括起来

public function votesThisMonth()
{
    $this->query = $this->pdo->prepare
    ("
        SELECT
            COUNT(*) AS num_votes
        FROM
            votes
        WHERE
            `year` = YEAR(CURRENT_DATE)
        AND `month` = MONTH(CURRENT_DATE)
    ");
    $result = $this->query->execute();

    return $result['num_votes'];
}

Answer 3

你应该这样做

public function votesThisMonth()
{
    $this->query = $this->pdo->prepare
    ("
        SELECT
            COUNT(*) AS num_votes
        FROM
            votes
        WHERE
            YEAR(year) = YEAR(CURRENT_DATE)
        AND MONTH(month) = MONTH(CURRENT_DATE)
    ");
    $this->query->execute();
    $result = $this->query->fetch(PDO::FETCH_ASSOC);

    return $result['num_votes'];
}