摘要:
聚合函数count(),sum(),max(),min(),avg() group by 按指定字段分组,分组后只能查询组信息 limit 10,5 表示限制查询结果,起始行下标10,总行数5 查询关键字顺序,select from where group by having order by 阅读全文
摘要:
Person类 package day1; public class Person { private String name; public int age; public Person(String name, int age) { this.name = name; this.age = ag 阅读全文