Question

我有一张这样的表：

╔════╦════════════╦══════════╗
║ id ║ project_id ║ document ║
╠════╬════════════╬══════════╣
║  1 ║     1      ║    3     ║
║  2 ║     1      ║    5     ║  
║  3 ║     2      ║    3     ║
║  4 ║     2      ║    4     ║
║  5 ║     3      ║    5     ║
║  6 ║     4      ║    2     ║
╚════╩════════════╩══════════╝

我希望所有project_id没有document = 5

换句话说，我想要这个结果：

╔════════════╗
║ project_id ║
╠════════════╣
║     2      ║
║     4      ║
╚════════════╝

Answer 1

试试这个：

SELECT project_id
FROM mytable
GROUP BY project_id
HAVING COUNT(CASE WHEN document = 5 THEN 1 END) = 0

Demo here

Answer 2

试试这个

SELECT DISTINCT project_id FROM project 
WHERE project_id NOT IN(
    SELECT project_id FROM project where document = 5
 )

Answer 3

以下是您可以尝试使用联接的版本：

SELECT t1.project_id
FROM
(
    SELECT project_id, COUNT(*) AS projectCount
    FROM mytable
    GROUP BY project_id
) t1
INNER JOIN
(
    SELECT project_id, COUNT(*) AS projectCount
    FROM mytable
    WHERE document <> 5
    GROUP BY project_id
) t2
    ON t1.project_id = t2.project_id AND t1.projectCount = t2.projectCount

请按照以下链接查看正在运行的演示：

SQLFiddle

选择与另一列相关的唯一值

3 个答案: