分析语句-GROUP BY

按字段的值分组

SELECT age GROUP BY age

按字段别名分组

SELECT account_number AS num GROUP BY num

按多个字段分组

SELECT account_number AS num, age GROUP BY num, age

使用SQL函数

函数相关内容请参见函数。

SELECT LENGTH(lastname) AS len, COUNT(*) AS count GROUP BY LENGTH(lastname)