程序媛计划——mysql 插入查找修改删除数据

Posted 2020-10-06 IcarusYu

#插入数据

[mysql>create table if not exists exam_score(
     ..>id int(4) not null primary key auto_increment,
     ..>name char(20) not null,
　　  ..>score double(6,2));

#用多个list插入多行数据 
[mysql> insert into exam_score values (1,‘Zhao‘,95.33),(2,‘Qian‘,94.33),(3,‘Sun‘,44.55),(4,‘Li‘,33.55);
Query OK, 4 rows affected (0.01 sec)
Records: 4  Duplicates: 0  Warnings: 0

#展示整张表
mysql> select * from exam_score;
+----+------+-------+
| id | name | score |
+----+------+-------+
|  1 | Zhao | 95.33 |
|  2 | Qian | 94.33 |
|  3 | Sun  | 44.55 |
|  4 | Li   | 33.55 |
+----+------+-------+
4 rows in set (0.00 sec)


mysql> insert into exam_score values (5,‘Zhou‘,66.33),(6,‘Wu‘,99.32),(7,‘Zheng‘,33.2),(8,‘Wang‘,99.3);
Query OK, 4 rows affected (0.00 sec)
Records: 4  Duplicates: 0  Warnings: 0

#查询按照字段id在0到2之间的行数据
mysql> select * from exam_score order by id limit 0,2;
+----+------+-------+
| id | name | score |
+----+------+-------+
|  1 | Zhao | 95.33 |
|  2 | Qian | 94.33 |
+----+------+-------+
2 rows in set (0.00 sec)

#查询整张表中的前两行
mysql> select * from exam_score limit 0,2;
+----+------+-------+
| id | name | score |
+----+------+-------+
|  1 | Zhao | 95.33 |
|  2 | Qian | 94.33 |
+----+------+-------+
2 rows in set (0.00 sec)

#按照name字段升序显示整张表
mysql> select * from exam_score order by name asc;
+----+-------+-------+
| id | name  | score |
+----+-------+-------+
|  4 | Li    | 33.55 |
|  2 | Qian  | 94.33 |
|  3 | Sun   | 44.55 |
|  8 | Wang  | 99.30 |
|  6 | Wu    | 99.32 |
|  1 | Zhao  | 95.33 |
|  7 | Zheng | 33.20 |
|  5 | Zhou  | 66.33 |
+----+-------+-------+
8 rows in set (0.01 sec)

#按照name降序显示
mysql> select * from exam_score order by name desc;
+----+-------+-------+
| id | name  | score |
+----+-------+-------+
|  5 | Zhou  | 66.33 |
|  7 | Zheng | 33.20 |
|  1 | Zhao  | 95.33 |
|  6 | Wu    | 99.32 |
|  8 | Wang  | 99.30 |
|  3 | Sun   | 44.55 |
|  2 | Qian  | 94.33 |
|  4 | Li    | 33.55 |
+----+-------+-------+
8 rows in set (0.00 sec)

#where条件查询 
mysql> select * from exam_score where name=‘Li‘;
+----+------+-------+
| id | name | score |
+----+------+-------+
|  4 | Li   | 33.55 |
+----+------+-------+
1 row in set (0.00 sec)

mysql> select * from exam_score where  id=3;
+----+------+-------+
| id | name | score |
+----+------+-------+
|  3 | Sun  | 44.55 |
+----+------+-------+
1 row in set (0.00 sec)

mysql> select * from exam_score where name=‘Zhao‘ and score<=99.0;
+----+------+-------+
| id | name | score |
+----+------+-------+
|  1 | Zhao | 95.33 |
+----+------+-------+
1 row in set (0.00 sec)