Question

我有一个表mes_transaction，其中有变量dc-它是 DEBIT 或 CREDIT 。我正在为另一个表编写sql过程（如果可以这样说）。在另一个表mes_aggregated_trx中，我有trx_amt-交易金额变量。基本上，我需要做的是编写一个过程，该过程基于trx_amt中的mes_aggregated_trx将dc中的mes_transaction加起来。

它需要看起来像这样（伪代码）：

如果dc ='CREDIT'，则添加ADDTOSUM（trx_amt）ELSE SUBFROMSUM（trx_amt）

我不知道如何在sql中实现IF子句。或者，也许我应该做一些事情，例如求和CREDIT trx_amt，然后求和DEBIT trx_amt，然后减去总和以获得所需的结果？但问题在于该过程如下所示：

$BODY$
BEGIN
    INSERT INTO mes_aggregated_trx(pos_id
                                  ,mes_account_id
                                  ,merchant_code
                                  ,trx_count
                                  ,fee_amount
                                  ,trx_amount
                                  ,date)
    SELECT pos_id
          ,mes_account_id
          ,merchant_code as location_id
          ,count(1) as count
          ,sum(comm_amt) as fee_amount
          ,sum(trx_amt) as trx_amount
          ,aggregation_date 
    FROM mes_transaction
    WHERE post_date =aggregation_date
    AND bic = aggregation_bic
    AND rec_type='TRX'
    AND (status='OK' OR status='OVR')
    GROUP BY pos_id, merchant_code, mes_account_id
    ON CONFLICT (date, merchant_code, pos_id, mes_account_id)
    DO UPDATE
       SET trx_count = excluded.trx_count
          ,trx_amount = excluded.trx_amount
          ,fee_amount = excluded.fee_amount;

    -- Conflicts shouldn't happen since before insert new trx for date everything
    -- for that date is cleaned, but to be 100% sure not to duplicate date, newest
    -- date is stored.
RETURN 1;  
END;
$BODY$

因此，我将需要以某种方式重做该过程的整个结构，而我对此并不十分了解。因此，任何帮助，技巧或建议都将非常有用！谢谢

Answer 1

IF dc = 'CREDIT' THEN ADDTOSUM(trx_amt) ELSE SUBFROMSUM(trx_amt)

在SQL中将类似于：

SUM(CASE WHEN dc='CREDIT' THEN trx_amt ELSE -(trx_amt) END)

在sql

1 个答案: