如何编写MySQL查询来实现此任务?
表:作家
w_id w_name
---------------
1 Michael
2 Samantha
3 John
---------------
表:文章
a_id w_id timestamp a_name
----------------------------------------
1 1 0000000001 PHP programming
2 3 0000000003 Other programming languages
3 3 0000000005 Another article
4 2 0000000015 Web design
5 1 0000000020 MySQL
----------------------------------------
只需要选择那些不早于 0000000005 发表第一篇文章的作者。((只能选择发表至少一篇文章的作者)
在此示例中,结果为:
2 Samantha
可以在此处测试SQL代码http://sqlfiddle.com/#!2/7a308
答案 0 :(得分:3)
未经测试,但很接近:
SELECT w_id, MIN(timestamp) as min_time
from writers w
JOIN articles a on w.w_id = a.w_id
GROUP BY 1
HAVING min_time > 5