收入低于凯瑟琳的教师姓名和人数

Question

显示教师人数和收入低于“凯瑟琳”的教师的姓名。

Answer 1

为什么不尝试一下，sql是如此简单

SELECT * FROM teacher WHERE salary <
 (SELECT salary FROM teachear WHERE name='Katherine')

OR

SELECT t1.* FROM teacher t1 
  JOIN teacher t2 ON t1.salary < t2.salary AND t2.name='atherine'

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更新的答案。

通常名称和总数不能在同一级别显示，如果要执行此操作，可以使用GROUP_CONCAT将所有名称组合为一个记录

SELECT count(t.teacher_id) AS count,GROUP_CONCAT(t.name) as names
FROM  teacher t
WHERE t.teacher_id IN
(
SELECT t1.teacher_id FROM teacher t1 
  JOIN teacher t2 ON t1.salary < t2.salary AND t2.name='atherine'
)