Alice's Secret Base
0%

Mysql Basis

Posted on Edited on In
Symbols count in article: 181 Reading time ≈ 1 mins.

关键字

distinct

1
2
3
4
5
6
SELECT DISTINCT(gender) FROM employees;

gender  
--------
M       
F

但是以下情况失效。这时适合用group by

1
2
SELECT DISTINCT(gender), emp_no FROM employees;
SELECT gender, emp_no FROM employees GROUP BY gender;