问：
I have a MySQL query and I ran it working fine but same query showing error in SQL Server.
SQL Server query:文章来源地址:https://www.yii666.com/article/756035.html
SELECT
COUNT(*) cnt
FROM
(SELECT DISTINCT
tc_id, MAX(exn_time), STATUS
FROM
release_details a, tc_details b
WHERE
a.project = b.project
AND a.tc_id = b.tc_name
AND logicaldel = 0
AND a.project = 'test'
GROUP BY
tc_id, STATUS) a
WHERE
a.status = 'PASS';
Error:
No column name was specified for column 2 of 'a'.
How do I modify the above query?文章地址https://www.yii666.com/article/756035.html
答：
Use the Alias name for your inner query.You are getting the MAX(exn_time) but not specified the name for that column that's why throwing the error. And you can use the Joins to the tables to make it more readable.网址:yii666.com
SELECT COUNT(*) cnt
FROM (
SELECT DISTINCT
tc_id,
MAX(exn_time) AS Maxtime ,
STATUS
FROM
release_details a JOIN tc_details b
ON a.project= b.project
AND a.tc_id = b.tc_name
WHERE
logicaldel = 0
AND a.project ='test'
GROUP BY
tc_id,
STATUS
) a
WHERE a.status='PASS';
所以记住SQL Server的子查询，每一列都要起个列名，否者会报错！
原文链接