sql 话语使用

sql 语句使用
1. 有一张表t_stu；其中三个字段:name,gender,grade；要求用一条sql语句查出男生前5名和女生前五名。

这里使用postgreSQL数据库

如果不考虑gender，只求前5名：


2. 有一张表t_game，记录了游戏玩家的id，游戏玩家名name，和每个玩家玩的游戏game，请找出玩游戏最多的那个玩家。

-- Create the table  CREATE TABLE intense.t_game(    id numeric(24),name character varying(20),    game character varying(20));-- Truncate the tabletruncate table intense.t_game;-- Insert datainsert into intense.t_game values(1,'John','game');insert into intense.t_game values(2,'Lisa','game2');insert into intense.t_game values(3,'Jack','game3');insert into intense.t_game values(4,'Jim','game4');insert into intense.t_game values(3,'Jack','game5');insert into intense.t_game values(5,'Eric','game6');insert into intense.t_game values(1,'John','game7');insert into intense.t_game values(3,'Jack','game8');insert into intense.t_game values(6,'Nicolas','game9');-- Get the data needed-- MySQL, postgreSQLselect id,name from intense.t_game group by id, name order by count(*) desc limit 1-- SQL Serverselect TOP 1 id,name from intense.t_game group by id, name order by count(*) desc-- Oracle