MS Access轉換查詢到MySQL查詢

Question

我正在將MS Access數據庫移至MySQL，並且遇到了一些查詢問題。

我大約有80％的人完成了轉移查詢的工作，但是這一特殊問題給我帶來了麻煩。

TRANSFORM Nz(Max(IIf([charge_description_code] In ('AHS','AHW','AHL','RES','SAT'),"Y","N")), "N") AS Data
SELECT shipment_details.tracking_number, shipment_details.invoice_number
FROM shipment_details
WHERE tracking_number is not null
and charge_category_detail_code not in ('RADJ')
GROUP BY shipment_details.tracking_number, shipment_details.invoice_number
PIVOT shipment_details.charge_description_code In (SAT,AHW,AHS,AHL,RES);

我希望結果顯示如下：

tracking_number invoice_number  SAT AHW AHS AHL RES
1Z2XXXXXXXXX625816  1329102975  N   N   N   N   N
1Z3YYYYYYYYY610514  1329109647  N   N   Y   N   N
1Z3ZZZZZZZZZ142605  1329109647  N   N   N   Y   Y

Answer 1

考慮條件聚合仍然可以在MS Access中使用（將IF替換為下面的IIF ）。 通常，Access的交叉表查詢不僅僅針對少數幾個，而且還針對少數幾個數據透視表。 同樣，由於條件邏輯將NULL解析為N ，因此NZ是多余的。

SELECT s.tracking_number, 
       s.invoice_number,
       MAX(IF(s.[charge_description_code] = 'SAT', 'Y', 'N')) AS 'SAT',
       MAX(IF(s.[charge_description_code] = 'AHW', 'Y', 'N')) AS 'AHW',
       MAX(IF(s.[charge_description_code] = 'AHL', 'Y', 'N')) AS 'AHL',
       MAX(IF(s.[charge_description_code] = 'AHS', 'Y', 'N')) AS 'AHS',
       MAX(IF(s.[charge_description_code] = 'RES', 'Y', 'N')) AS 'SAT'

FROM shipment_details s
WHERE s.tracking_number IS NOT NULL
  AND s.charge_category_detail_code NOT IN ('RADJ')
  AND s.charge_description_code IN ('AHS','AHW','AHL','RES','SAT')

GROUP BY s.tracking_number, 
         s.invoice_number

Answer 2

我認為transform返回未設置任何值的行。 在這種情況下，適當的轉換更像這樣：

SELECT s.tracking_number, s.invoice_number,
       MAX(CASE WHEN s.charge_description_code = 'SAT' THEN 'Y' ELSE 'N' END) AS SAT,
       MAX(CASE WHEN s.charge_description_code = 'AHW' THEN 'Y' ELSE 'N' END) AS AHW,
       MAX(CASE WHEN s.charge_description_code = 'AHL' THEN 'Y' ELSE 'N' END) AS AHL,
       MAX(CASE WHEN s.charge_description_code = 'AHS' THEN 'Y' ELSE 'N' END) AS AHS,
       MAX(CASE WHEN s.charge_description_code = 'RES' THEN 'Y' ELSE 'N' END) AS RES
FROM shipment_details s
WHERE s.tracking_number IS NOT NULL AND
      s.charge_category_detail_code NOT IN ('RADJ')
GROUP BY s.tracking_number, s.invoice_number;