Question

我正在使用Oracle。我正在尝试写这样的东西：

SELECT trans_type,
(SELECT parameter_value FROM transaction_details WHERE id = MAX(t.trans_id))
FROM
(SELECT trans_id, trans_type FROM transactions) t
GROUP BY trans_type

所以，我试图在内部查询中使用分组结果。但我得到的错误是我不能在内部查询中使用组函数：

ORA-00934: group function is not allowed here

除了诉诸另一个外部查询外，您能提供其他选择吗？

更新

根据要求，我发布了一个较短版本的真实查询：

  SELECT service_code,
         currency,
         (SELECT value FROM exchange_rate WHERE date_added = MIN(t.trans_date)) AS exchange_rate,
         TRIM(TO_CHAR(SUM(amount), '9999999990.99')) AS amount,
         TRIM(TO_CHAR(SUM(tax_amount), '9999999990.99')) AS tax_amount,
         TRIM(TO_CHAR(SUM(total_amount), '9999999990.99')) AS total_amount
    FROM (SELECT t.amount AS amount,
                t.trans_date AS trans_date
                 t.tax_amount AS tax_amount,
                 t.total_amount AS total_amount,
                 td1.string_value AS service_code,
                 td2.string_value AS currency
            FROM transac) t
GROUP BY service_code, currency

Answer 1

更传统的查询有什么问题：

SELECT t.trans_type, td.parameter_value, MAX(t.trans_id)
  FROM transactions t
 INNER 
  JOIN transaction_details td ON td.id = t.trans_id
 GROUP BY t.trans_type, td.parameter_value

Answer 2

我认为你所寻找的是这样的：

  SELECT service_code,
         currency,
         er.value as exchange_rate,
         TRIM(TO_CHAR(SUM(amount), '9999999990.99')) AS amount,
         TRIM(TO_CHAR(SUM(tax_amount), '9999999990.99')) AS tax_amount,
         TRIM(TO_CHAR(SUM(total_amount), '9999999990.99')) AS total_amount
    FROM (SELECT t.amount AS amount,
                 t.tax_amount AS tax_amount,
                 t.total_amount AS total_amount,
                 td1.string_value AS service_code,
                 td2.string_value AS currency,
                 min(t.trans_date) 
                     over (partition by td1.string, 
                                        td2.string) as min_trans_date
            FROM transac t, table2 td1, table3 td2) t,
          exchange_rate er
   WHERE er.date_added = t.min_trans_date

我不确定这是否真的是您的解决方案，因为根据您的查询，我无法确定您想要的最小交易日期基于哪个组。此版本假定您需要服务代码和货币的给定组合的最早交易日期。

你的方法遇到了几个问题：

SELECT子句中的任何列需要要么在GROUP BY中条款或受集合约束功能。你有几列没有这个标准。
您正在尝试使用聚合函数来自外部查询标量子查询。你不能这样做那。充其量，你可以得到然后，在嵌套查询中聚合稍后引用该值。

内部查询内外部查询的组函数

2 个答案: