Question

我从事务表中获取order_id，created_at date，transaction_amount。我使用order_id，其created_at日期和transaction_amount获得了一些记录。现在我想要transaction_amount列的总和。我尝试在db上直接查询哪个工作正常，但我无法在laravel中编写相同的查询。

select sum(transaction_amount) from (
select order_id, max(created_at), transaction_amount
from transactions
WHERE user_id =100 AND accounting_type = "Debit"
group by order_id
limit 500 ) as transactions

我试过这种方式但仍然无法正常工作

$sql = "select sum(transaction_amount) from 
                ('select order_id, max(created_at), transaction_amount
                from transactions
                WHERE user_id =100 
                group by order_id
                limit 500') as transactions";
        $result = \DB::select( \DB::raw($sql));

Answer 1

首先，让我们分解您的查询：主要查询

SELECT
SUM( transaction_amount )
FROM
    (...) AS transactions

这只是用于总结。你的子查询：

        SELECT
            order_id,
            MAX( created_at ),
            transaction_amount
        FROM
            transactions
        WHERE
            user_id = 100
            AND accounting_type = "Debit"
        GROUP BY
            order_id LIMIT 500

对于子查询，Laravel查询构建器应为：

use DB;

$result = DB::table('table')
->select(DB::raw("order_id, MAX(created_at), transaction_amount"))
->where("user_id", "=", 100)
->where("accounting_type", "=", "Debit")
->groupBy("order_id")
->limit(500)
->get(); // this will return Laravel Collection (Illuminate\Support\Collection)

Laravel Collection有sum方法，所以你可以调用它

$result->sum('transaction_amount');

有关详情，请参阅this和this Laravel文档。

Answer 2

我认为您的$sql变量必须只包含FROM中的子查询。

Laravel QueryBuilder的table()方法是＆＃34; 等效＆＃34;在SQL中FROM语句中，您可以放置子查询。

尝试

$sql = 'select order_id, max(created_at), transaction_amount
            from transactions
            WHERE user_id =100 
            group by order_id
            limit 500';

$result = \DB::table(\DB::raw($sql))->sum('transaction_amount');

相反，如果您想要与您尝试使用的select()方法并行：

$result = \DB::table(\DB::raw($sql))->select(\DB::raw('sum(transaction_amount) as sum'))->get();

如何将自定义查询转换为laravel 5？

2 个答案: