我有個同學最近在學Mysql數據庫，爲了測試自己的學習成果，他們老大出了6道Mysql試題讓他去做，晚上回來他又分享給我，我感覺非常經典，記錄了這幾道試題已及答案。
將測試數據表導入數據庫，其中name字段代表“姓名”，score字段代表“分數”。
create table `t1` (
`id` double ,
`name` varchar (300),
`score` double
);
insert into `t1` (`id`, `name`, `score`) values('1','n1','59');
insert into `t1` (`id`, `name`, `score`) values('2','n2','66');
insert into `t1` (`id`, `name`, `score`) values('3','n3','78');
insert into `t1` (`id`, `name`, `score`) values('4','n1','48');
insert into `t1` (`id`, `name`, `score`) values('5','n3','85');
insert into `t1` (`id`, `name`, `score`) values('6','n5','51');
insert into `t1` (`id`, `name`, `score`) values('7','n4','98');
insert into `t1` (`id`, `name`, `score`) values('8','n5','53');
insert into `t1` (`id`, `name`, `score`) values('9','n2','67');
insert into `t1` (`id`, `name`, `score`) values('10','n4','88');
1. 單分數最高的人和單分數最低的人。
mysql> select name,max(score) from t1;
2. 兩門分數加起來的第2至5名。
mysql> select name,sum(score) from t1 group by name order by sum(score) desc limit 1,4;
+------+------------+
| name | sum(score) |
+------+------------+
| n3 | 163 |
| n2 | 133 |
| n1 | 107 |
| n5 | 104 |
+------+------------+
3. 兩門總分數在150分以下的人。
select name sum(score) from t1 group by name having sum(score) < 150;
4. 兩門平均分數介於60和80的人。
select name,avg(score) from t1 group by name having avg(score) between 60 and 80;
select name,avg(score) from t1 group by name having ave(score) >60 and avg(score) <80;
5. 總分大於150分，平均分小於90分的人數。
mysql> select name,sum(score),avg(score) from t1 group by name having sum(score)>150 and avg(score)<90;
+------+------------+------------+
| name | sum(score) | avg(score) |
+------+------------+------------+
| n3 | 163 | 81.5 |
+------+------------+------------+
1 row in set (0.00 sec)
6. 總分大於150分，平均分小於90分的人數有幾個。
select count(distinct name) from t1 group by name having sum(score) > 150 and avg(score) < 90;
本文出自 “樸實的追夢者” 博客，請務必保留此出處http://sfzhang88.blog.51cto.com/4995876/871823