PostgreSQL案例，然后再结束错误

Question

使用v9.1时，我工作得很好，但是升级到v9.4后，以下操作失败。

SELECT   a.account_id 
         ( 
                select round(cast(sum(WHEN c.transaction_type = 'Ranger' THEN c.original_currency ELSE c.original_currency * -1
         end)) AS NUMERIC), 
                       2) 
FROM     account_transaction AS c 
WHERE    a.account_id = c.account_id 
GROUP BY c.account_id) 
AS 
  balance_amount 
  FROM account 
AS 
  a LEFT JOIN account_type 
AS 
  b ON a.account_type_id = b.account_type_id 
  WHERE ( 
    b.description >= 'Boomberang' AND b.description <= 'Boomberang' 
  );

WHEN或附近的语法错误

我用谷歌搜索，但不能解决问题。 请帮忙。

Answer 1

看起来您缺少CASE关键字，请尝试以下操作：

(CASE WHEN c.transaction_type = 'Ranger' THEN c.original_currency ELSE c.original_currency * -1 END)

Answer 2

您是说CASE WHEN而不是WHEN吗？