PostgreSQL选择列，然后添加随机值

Question

解决了！ 感谢Gordon Linoff！

是否可以在PostgreSQL中获得这样的查询结果？

UserName | Count |
Sukri    |   1   |
Azis     |   2   |
Adit     |   1   |
Total    |   4   |

行“总计”值是3列的总和。

SELECT 
CASE 
    WHEN (res."UserName"IS NULL OR res."UserName" = '') THEN 'TOTAL' 
    ELSE res."UserName"
END AS "UserName",
res."Count"
FROM
(
    SELECT "UserName", count("UserName") AS "Count"
    FROM "Ticket"
    GROUP BY GROUPING SETS ( ("UserName"), () ) ORDER BY "UserName"
) AS res

Answer 1

我想这是一个聚合查询。 如果是这样，请使用grouping sets （或rollup ）：

select coalesce(username, 'Total') as userid, count(*) as cnt
from t
group by grouping sets ( (username), () );