Question

（使用django 1.11.2，python 2.7.10，mysql 5.7.18）

以下SQL查询：

average_time_of_day = Transaction.objects.raw(
    '''
    SELECT 
        transaction_transaction.id, 
        sec_to_time(avg(time_to_sec(extract(HOUR_SECOND from transaction_transaction.transaction_datetime)))) 
        AS average_time_of_day
    FROM transaction_transaction
    INNER JOIN store_store ON (transaction_transaction.store_id=store_store.id) 
    %s
    WHERE (
        transaction_transaction.transaction_datetime BETWEEN %s AND %s 
        AND store_store.company_id=%s
        %s
    );
    ''',
    [
        'INNER JOIN payment_method_card ON (transaction_transaction.card_id=payment_method_card.id) ' if profile_pk else '',
        start_datetime,
        end_datetime,
        company_pk,
        'AND payment_method_card.profile_id=' + str(profile_pk) if profile_pk else '',
    ]
)

运行并返回以下结果（如预期的那样）：

print average_time_of_day.query

（这是从HeidiSQL运行的）

通过Django做类似的事情（我认为！但显然有些错误）：

SELECT
    transaction_transaction.id,
    sec_to_time(avg(time_to_sec(extract(HOUR_SECOND from transaction_transaction.transaction_datetime))))
    AS average_time_of_day
FROM transaction_transaction
INNER JOIN store_store ON (transaction_transaction.store_id=store_store.id)
INNER JOIN payment_method_card ON (transaction_transaction.card_id=payment_method_card.id)
WHERE (
    transaction_transaction.transaction_datetime BETWEEN 2017-08-31 00:00:00 AND 2017-08-31 00:00:00
    AND store_store.company_id=2
    AND payment_method_card.profile_id=8
);

否则

ProgrammingError: (1064, "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''INNER JOIN payment_method_card ON (transaction_transaction.card_id=payment_meth' at line 7")

输出：

        $y = 1;
        $period = 3;
        $start = date('m/d/Y');
        $end = date('m/t/Y');
        echo "<table>";
        echo '<thead><th>From</th>';
        echo '<th>To</th></thead>';

        for ($y; $y <= $period; $y++) {
         echo '<tr><td>'.$start.'</td>';
         echo '<td>'.$end.'</td></tr>';

         $getLast = date('d',strtotime($end));

             if($getLast >= 28) {
                $start = date("m/t/Y", strtotime($start)); 
                $end = date("m/d/Y", strtotime("+15 day", strtotime($end))); 
             }else {
                $start = date("m/d/Y", strtotime("+15 day", strtotime($start))); 
                $end = date("m/t/Y",strtotime($end));   
             }
        }

        echo "</table>";

Django返回时出现以下错误：

From    To
09/15/2017  09/30/2017
09/30/2017  10/15/2017
10/15/2017  10/31/2017

知道我做错了吗？

Answer 1

您是否尝试过使用Django的ORM来构建该查询？它可以使调试更容易。它可能看起来像这样：

Transaction.objects.filter(
    store__company_id=company_pk,
    payment_method_card__profile_id=profile_pk,
    transaction_datetime__range(start_datetime, end_datetime)
)

您可以在查询中使用Django's select_related and prefetch_related优化查询，如果需要更细粒度的控制，则可以使用Q() object。

我不喜欢手动编写SQL语句，所以这有点像一个副本，但我喜欢使用Django给我的工具。

Answer 2

在SQL字符串中，某些变量必须是字符串。例如，datetime必须在“”或“我不记得但queryset.query显示您格式化的sql字符串无效的字符串。所以只需尝试添加''。

Answer 3

右。

这个会教我不要尝试：

太聪明了
过多地使用单行： - （

这不起作用：

average_time_of_day = Transaction.objects.raw(
    '''
    SELECT 
        transaction_transaction.id, 
        sec_to_time(avg(time_to_sec(extract(HOUR_SECOND from transaction_transaction.transaction_datetime)))) 
        AS average_time_of_day
    FROM transaction_transaction
    INNER JOIN store_store ON (transaction_transaction.store_id=store_store.id) 
    %s
    WHERE (
        transaction_transaction.transaction_datetime BETWEEN %s AND %s 
        AND store_store.company_id=%s
        %s
    );
    ''',
    [
        'INNER JOIN payment_method_card ON (transaction_transaction.card_id=payment_method_card.id) ' if profile_pk else '',
        start_datetime,
        end_datetime,
        company_pk,
        'AND payment_method_card.profile_id=' + str(profile_pk) if profile_pk else ''
    ]
)

请注意发送到raw（）方法的'INNER JOIN payment_method_card ON (transaction_transaction.card_id=payment_method_card.id) ' if profile_pk else ''中的'AND payment_method_card.profile_id=' + str(profile_pk) if profile_pk else ''和params。有点动态吗？

...但此有效：

if profile_pk:
    average_time_of_day = Transaction.objects.raw(
        '''
        SELECT
            transaction_transaction.id,
            sec_to_time(avg(time_to_sec(extract(HOUR_SECOND from transaction_transaction.transaction_datetime))))
            AS average_time_of_day
        FROM transaction_transaction
        INNER JOIN store_store ON (transaction_transaction.store_id=store_store.id)
        INNER JOIN payment_method_card ON (transaction_transaction.card_id=payment_method_card.id)
        WHERE (
            transaction_transaction.transaction_datetime BETWEEN %s AND %s
            AND store_store.company_id=%s
            AND payment_method_card.profile_id=%s
        );
        ''',
        [
            start_datetime,
            end_datetime,
            company_pk,
            profile_pk
        ]
    )
else:
    average_time_of_day = Transaction.objects.raw(
        '''
        SELECT
            transaction_transaction.id,
            sec_to_time(avg(time_to_sec(extract(HOUR_SECOND from transaction_transaction.transaction_datetime))))
            AS average_time_of_day
        FROM transaction_transaction
        INNER JOIN store_store ON (transaction_transaction.store_id=store_store.id)
        WHERE (
            transaction_transaction.transaction_datetime BETWEEN %s AND %s
            AND store_store.company_id=%s
        );
        ''',
        [
            start_datetime,
            end_datetime,
            company_pk
        ]
    )

那么Django可能不喜欢params的动态构建吗？我很高兴知道答案......我仍然怀疑我做错了什么，但是......这与SQL注入保护有什么关系吗？

显然Django将INNER JOIN表达式包装在单引号中 - 因此导致MySQL拒绝查询。实际上看起来像这样，即使print average_time_of_day.query没有说出任何内容：

SELECT
    transaction_transaction.id,
    sec_to_time(avg(time_to_sec(extract(HOUR_SECOND from transaction_transaction.transaction_datetime))))
    AS average_time_of_day
FROM transaction_transaction
INNER JOIN store_store ON (transaction_transaction.store_id=store_store.id)
'INNER JOIN payment_method_card ON (transaction_transaction.card_id=payment_method_card.id)'
WHERE (
    transaction_transaction.transaction_datetime BETWEEN 2017-08-31 00:00:00 AND 2017-08-31 23:59:59
    AND store_store.company_id=2
    'AND payment_method_card.profile_id=8'
);

Django .raw查询失败（错误1064） - 但在SQL中工作

3 个答案: