Question

希望你能帮助我解决这个我正在努力解决的问题。目前我有以下SQL工作正常，但我想包括end_date列，但即使SYSDATE（）＆lt; = end_date仍然返回值。这是没有end_date条件和结果的查询：

SELECT pkgCnt.holiday_type_desc, COUNT(DISTINCT pkgCnt.package_heading) AS count
FROM package pkg,
(
    SELECT pkg.holiday_type_id, holiday_type_desc, package_heading
    FROM package pkg
    INNER JOIN holiday_type ht ON pkg.holiday_type_id = ht.holiday_type_id
    GROUP BY pkg.holiday_type_id, package_heading
) AS pkgCnt
INNER JOIN holiday_type ht ON pkgCnt.holiday_type_id = ht.holiday_type_id
WHERE pkg.package_heading = pkgCnt.package_heading
GROUP BY pkg.holiday_type_id
ORDER BY pkg.holiday_type_id;

结果如下，这是完美的：

holiday_type_desc   count
Bush Breaks         6
City Breaks         5
Golf Breaks         1
Adventure Holidays  3
Beach Holidays      5
Family Holidays     1

但是当我按照下面的查询所示添加end_date时，结果为空：

SELECT pkgCnt.holiday_type_desc, COUNT(DISTINCT pkgCnt.package_heading) AS count
FROM package pkg,
(
    SELECT pkg.holiday_type_id, holiday_type_desc, package_heading
    FROM package pkg
    INNER JOIN holiday_type ht ON pkg.holiday_type_id = ht.holiday_type_id
    GROUP BY pkg.holiday_type_id, package_heading
) AS pkgCnt
INNER JOIN holiday_type ht ON pkgCnt.holiday_type_id = ht.holiday_type_id
WHERE pkg.package_heading = pkgCnt.package_heading
AND SYSDATE() <= pkg.end_date
GROUP BY pkg.holiday_type_id
ORDER BY pkg.holiday_type_id;

但我希望查询返回以下内容：

holiday_type_desc   count
Bush Breaks         0
City Breaks         0
Golf Breaks         0
Adventure Holidays  0
Beach Holidays      0
Family Holidays     0

Answer 1

我认为你也可以这样做 -

SELECT pkgCnt.holiday_type_desc,
         COUNT(DISTINCT pkgCnt.package_heading) AS count,
         sum(case
               when SYSDATE() <= pkg.end_date then
                1
               else
                0
             end) as count_after_codition
    FROM package pkg,
         (SELECT pkg.holiday_type_id, holiday_type_desc, package_heading
            FROM package pkg
           INNER JOIN holiday_type ht
              ON pkg.holiday_type_id = ht.holiday_type_id
           GROUP BY pkg.holiday_type_id, package_heading) AS pkgCnt
   INNER JOIN holiday_type ht
      ON pkgCnt.holiday_type_id = ht.holiday_type_id
   WHERE pkg.package_heading = pkgCnt.package_heading
   GROUP BY pkg.holiday_type_id
   ORDER BY pkg.holiday_type_id;

Answer 2

感谢@pratik garg，我设法找到了我想要的解决方案。请在下面找到最终的SQL：

SELECT pkgCnt.holiday_type_desc,
    CASE
        WHEN SYSDATE() <= pkg.end_date THEN
            COUNT(DISTINCT pkgCnt.package_heading)
        ELSE
            0
    END count
FROM package pkg,
(
    SELECT pkg.holiday_type_id, holiday_type_desc, package_heading
    FROM package pkg
    INNER JOIN holiday_type ht
    ON pkg.holiday_type_id = ht.holiday_type_id
    GROUP BY pkg.holiday_type_id, package_heading
) AS pkgCnt INNER JOIN holiday_type ht ON pkgCnt.holiday_type_id = ht.holiday_type_id
WHERE pkg.package_heading = pkgCnt.package_heading
GROUP BY pkg.holiday_type_id
ORDER BY pkg.holiday_type_id;

即使在SQL

2 个答案: