SQL 查询使用计数和大于

Question

I'm still learning.

How would I make this query work

mysql> select publisher
    -> from books
    -> where count(publisher) > 3;

The syntax is not correct, but I want to know how to find the name of the publisher where the number of (times that publisher appears in my table) is greater than 3.

Thanks

Answer 1

You need to GROUP BY Publisher and a HAVING clause:

SELECT Publisher
FROM Books
GROUP BY Publisher
HAVING COUNT(*) > 3

Answer 2

This is TSQL but will probably give you what you need..

SELECT Publisher, SUM(1) [Count]
FROM Books
GROUP BY Publisher
HAVING SUM(1) > 3

Answer 3

the most simple way to do it is using subquery:

mysql> select publisher
-> from books
-> where 3 < (select count(publisher) from books);