Question

我正在努力为我们在损坏自己设备的地方完成维修工作（我知道......这很疯狂）。

基本上，我希望能够查看零件的总维修时数，然后还可以查看通过不同类型的维修分解了多少小时。我的代码如下，我希望实现这一目标：

我的代码如下：

SELECT 
            PART_NUM,
            PART_NAME,
            PART_SERIAL_NUM,
            SUM(REPAIR_HOURS) AS "TOTAL_REPAIR_HOURS",
            CASE WHEN REPAIR_TYPE = 'A' THEN SUM(REPAIR_HOURS) END AS "CONCRETE_HOURS",
            CASE WHEN REPAIR_TYPE = 'B' THEN SUM(REPAIR_HOURS) END AS "DEMOLITION_HOURS",
            CASE WHEN REPAIR_TYPE = 'C' THEN SUM(REPAIR_HOURS) END AS "AUTOMOTIVE_HOURS"

        FROM 
            PARTS
                LEFT JOIN REPAIRS
                     ON PART_NUM = REPAIRED_PART AND 
                        PART_SERIAL_NUM = REPAIRED_PART_SERIAL_NUM

        WHERE
            PART_NUM = '500ABX'

        GROUP BY 
            PART_NUM,
            PART_NAME,
            PART_SERIAL_NUM

（我显然一次只在一个部件上进行测试:)）

我不断收到错误

ORA-00979：不是GROUP BY表达式（＃979）。

我试图删除CASE WHEN语句，它运行正常。只有在我添加这些内容时，我才会遇到问题。

任何帮助将不胜感激！：）

Answer 1

你需要案例表达式里面聚合，而不是反过来：

SELECT 
            PART_NUM,
            PART_NAME,
            PART_SERIAL_NUM,
            SUM(REPAIR_HOURS) AS "TOTAL_REPAIR_HOURS",
            SUM(CASE WHEN REPAIR_TYPE = 'A' THEN REPAIR_HOURS ELSE 0 END) AS "CONCRETE_HOURS",
            SUM(CASE WHEN REPAIR_TYPE = 'B' THEN REPAIR_HOURS ELSE 0 END) AS "DEMOLITION_HOURS",
            SUM(CASE WHEN REPAIR_TYPE = 'C' THEN REPAIR_HOURS ELSE 0 END) AS "AUTOMOTIVE_HOURS"

        FROM 
            PARTS
                LEFT JOIN REPAIRS
                     ON PART_NUM = REPAIRED_PART AND 
                        PART_SERIAL_NUM = REPAIRED_PART_SERIAL_NUM

        WHERE
            PART_NUM = '500ABX'

        GROUP BY 
            PART_NUM,
            PART_NAME,
            PART_SERIAL_NUM

Oracle SQL - 使用CASE WHEN语句时无效的GROUP BY

1 个答案: