Mysql Sql:在STR\u到\u日期范围内选择

我的sql只适用于一个日期，现在我想按范围选择，我可以如何添加范围日期

SELECT 
        products.id, 
        products.name, 
        (select ifnull(sum(stocks.qty),0) from stocks where stocks.pid=products.id and DATE(stocks.created_at) = STR_TO_DATE('15,4,2020','%d,%m,%Y') ) as stock_in_today,

        (select ifnull(sum(loadings.qty),0) from loadings where loadings.pid=products.id and DATE(loadings.created_at) = STR_TO_DATE('15,4,2020','%d,%m,%Y') ) as total_loadings_today,

        (select ifnull(sum(stocks.qty),0) from stocks where stocks.pid=products.id) as total_stock_till_date,

        (select ifnull(sum(loadings.qty),0) from loadings where loadings.pid=products.id) as total_loadings_till_date,

        ((select ifnull(sum(stocks.qty),0) from stocks where stocks.pid=products.id and DATE(stocks.created_at) < STR_TO_DATE('15,4,2020','%d,%m,%Y'))-(select ifnull(sum(loadings.qty),0) from loadings where loadings.pid=products.id and DATE(loadings.created_at) < STR_TO_DATE('15,4,2020','%d,%m,%Y'))) as opening_balance,

        ((select ifnull(sum(stocks.qty),0) from stocks where stocks.pid=products.id and DATE(stocks.created_at) <= STR_TO_DATE('15,4,2020','%d,%m,%Y'))-(select ifnull(sum(loadings.qty),0) from loadings where loadings.pid=products.id and DATE(loadings.created_at) <= STR_TO_DATE('15,4,2020','%d,%m,%Y'))) as closing_balance

        from products

我的看法

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您可以使用相关子查询。以下是一个例子：

select d.dte,
       p.id, p.name,
        (select coalesce(sum(s.qty), 0)
         from stocks s
         where s.pid = p.id and
               s.created_at >= d.dte and
               s.created_at < d.dte + interval 1 day
        ) as stock_in_today,
        . . .
from products p cross join
     (select date('2020-01-01') as dte union all
      select date('2020-02-01')
     ) d

对于其余的子查询，依此类推

请注意我对查询所做的更改：

添加了表别名，因此表引用更易于写入和读取。 对日期文本使用标准日期格式。 将日期逻辑更改为使用直接比较而不是函数。

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此查询可以使用stockpid上的索引，该索引创建于。

@EmmaMfinanga。只有在d派生表中有重复项时，结果才会相乘。我没有重复的id