从titles表获取按照title进行分组,每组个数大于等于2,给出title以及对应的数目t。
CREATE TABLE IF NOT EXISTS "titles" (
emp_no int(11) NOT NULL,
title varchar(50) NOT NULL,
from_date date NOT NULL,
to_date date DEFAULT NULL);
输入描述:

输出描述:

title                           t

Assistant Engineer              2

Engineer                        4

省略                            省略

Staff                           3

题解:

SELECT title, COUNT(title) T FROM titles
GROUP BY title HAVING T >= 2