Question

select  CASE WHEN ( rtt.us_code = 's' )
                  THEN rtt.name
                  ELSE '' END AS input_tax_name,
             CASE WHEN ( rtt2.us_code = 'r')
                  THEN rtt2.name
                  ELSE '' END AS output_tax_name,
             CASE WHEN ( rtt.us_code = 's' )
                  THEN rtt.acc_id
                  ELSE 0 END AS input_tax_rate,
             CASE WHEN ( rtt2.us_code = 'r')
                  THEN rtt2.acc_id
                  ELSE 0 END AS output_tax_rate
from supplier_item si
JOIN ret_tx_type  rtt
ON si.ret_tx_type_id = rtt.ret_tx_type_id
JOIN ret_tx_type  rtt2
ON si.ret_tx_type_id = rtt2.ret_tx_type_id
 where si.ret_tx_type_id is not null

我试图在报告的同一行显示输入和输出税取决于us_code是'r'和's'。但我得到的结果如

如果有输入税...输出税栏将为空如果有输出税...输入税栏将为空

我希望在同一行中获取两者，而不需要在任何行中使用null

请帮助

Answer 1

SELECT
  MAX(CASE rtt.us_code WHEN 's' THEN rtt.name END) AS input_tax_name,
  MAX(CASE rtt.us_code WHEN 'r' THEN rtt.name END) AS output_tax_name,
  MAX(CASE rtt.us_code WHEN 's' THEN rtt.acc_id END) AS input_tax_rate,
  MAX(CASE rtt.us_code WHEN 'r' THEN rtt.acc_id END) AS output_tax_rate
FROM supplier_item si
  INNER JOIN ret_tx_type rtt
    ON si.ret_tx_type_id = rtt.ret_tx_type_id
GROUP BY ??? /* here you should supply a column,
                presumably in 'si', that is common
                to both of the related 'r'- and
                's'-tax records */

Answer 2

您需要在查询中添加GROUP BY内容（可能GROUP BY si.id？）

将CASE语句放入聚合中。 e.g。

MAX(CASE WHEN ( rtt2.us_code = 'r')
                  THEN rtt2.acc_id
                  ELSE 0 END)

Case语句问题，用于显示连续不带null的值

2 个答案: