php - 努力将 WHERE 子句添加到 INNER JOIN

Question

我有一个查询，应该从每个 backend_hotels_id date_start 和 package_supplier 中选择最低的 price_per_pax_after_tax 并且在我添加 WHERE 子句之前，这似乎一直有效。

这是查询:

SELECT e.price_per_pax_after_tax, e.hotel_score, e.package_id, e.package_type
FROM packages_sorted_YQU e
INNER JOIN (
  SELECT db_id, MIN( price_per_pax_after_tax ) AS lowest_price, package_id, hotel_score
  FROM `packages_sorted_YQU`
  WHERE `package_type` IN ('9', '10', '18') 
  AND `package_duration` IN ('6', '8', '12')
  GROUP BY 
    `date_start` , `package_supplier` , `backend_hotels_id`
) AS j 
ON j.db_id = e.db_id
AND j.lowest_price= e.price_per_pax_after_tax
AND j.hotel_score = e.hotel_score
AND j.package_id = e.package_id;

表格很大，但列出的所有字段都是 INT，除了 date_start 是 DATE

导致问题的where子句是:

WHERE `package_type` IN ('9', '10', '18') 
AND `package_duration` IN ('6', '8', '12')

如果没有 where 子句，我会得到超过 400 个结果，如果有 where 子句，我会得到零个结果:( 非常感谢任何帮助。

Answer 1

如果您的列 package_type 和 package_duration 的类型为 int，则不必将值包装在 ' 就像字符串一样。

SELECT e.price_per_pax_after_tax, e.hotel_score, e.package_id, e.package_type
FROM packages_sorted_YQU e
INNER JOIN (
  SELECT db_id, MIN( price_per_pax_after_tax ) AS lowest_price, package_id, hotel_score
  FROM `packages_sorted_YQU`
  WHERE `package_type` IN (9, 10, 18) 
  AND `package_duration` IN (6, 8, 12)
  GROUP BY 
    `date_start` , `package_supplier` , `backend_hotels_id`
) AS j 
ON j.db_id = e.db_id
AND j.lowest_price= e.price_per_pax_after_tax
AND j.hotel_score = e.hotel_score
AND j.package_id = e.package_id;