sql 基础--mysql 5

mysql5.6 安装 http://jingyan.baidu.com/article/f3ad7d0ffc061a09c3345bf0.html

md中输入:net start mysql,服务启动成功

mysql -u root -p（第一次登录没有密码，直接按回车过）,登录成功！

1.使用database

show databases;

use t_database;

show tables;

show columns from pw_luck;

mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
+--------------------+
3 rows in set (0.00 sec)

mysql> use mysql
Database changed
mysql> show tables;
+---------------------------+
| Tables_in_mysql |
+---------------------------+
| columns_priv |
| db |
| event |
| func |
| general_log |
| help_category |
| help_keyword |
| help_relation |
| help_topic |
| innodb_index_stats |
| innodb_table_stats |
| ndb_binlog_index |
| plugin |
| proc |
| procs_priv |
| proxies_priv |
| servers |
| slave_master_info |
| slave_relay_log_info |
| slave_worker_info |
| slow_log |
| tables_priv |
| time_zone |
| time_zone_leap_second |
| time_zone_name |
| time_zone_transition |
| time_zone_transition_type |
| user |
+---------------------------+
28 rows in set (0.00 sec)

　2.查询

　单列：select name from pw_luck;

　多列：select uid,name from pw_luck;

   所有：select * from pw_luck;

   distinct关键字（去重）：select distinct name from pw_luck;

　　注意：用在多个列上表示多个列值都一样才会被去重

mysql> select * from pw_luck;
+-----+-----------+------+
| uid | name      | msg  |
+-----+-----------+------+
|   0 | Wilson    |  100 |
|   1 | zhangsan  |  100 |
|   2 | lisi      | 1001 |
|   3 | wang5     | 1001 |
|   7 | zhangsan7 | 1000 |
|   8 | zhangsan8 | 1000 |
|   9 | zhangsan9 | 1000 |
|  10 | wang5     | 1000 |
+-----+-----------+------+
8 rows in set (0.00 sec)

mysql> select distinct name from pw_luck;
+-----------+
| name      |
+-----------+
| Wilson    |
| zhangsan  |
| lisi      |
| wang5     |
| zhangsan7 |
| zhangsan8 |
| zhangsan9 |
+-----------+
7 rows in set (0.00 sec)

mysql> select distinct name,msg from pw_luck;
+-----------+------+
| name      | msg  |
+-----------+------+
| Wilson    |  100 |
| zhangsan  |  100 |
| lisi      | 1001 |
| wang5     | 1001 |
| zhangsan7 | 1000 |
| zhangsan8 | 1000 |
| zhangsan9 | 1000 |
| wang5     | 1000 |
+-----------+------+
8 rows in set (0.00 sec)

　　想要得到多个列的结果且要对某一列去重 需要用到 group by 函数

mysql> select name,msg from pw_luck group by name;
+-----------+------+
| name      | msg  |
+-----------+------+
| lisi      | 1001 |
| wang5     | 1001 |
| Wilson    |  100 |
| zhangsan  |  100 |
| zhangsan7 | 1000 |
| zhangsan8 | 1000 |
| zhangsan9 | 1000 |
+-----------+------+
7 rows in set (0.00 sec)

　　限制结果：limit 2 表示 0-2行 limit 2，2 表示2行开始长度2行

如 select * from pw_luck limit 2,2

mysql> select * from pw_luck limit 2;
+-----+----------+-----+
| uid | name     | msg |
+-----+----------+-----+
|   0 | Wilson   | 100 |
|   1 | zhangsan | 100 |
+-----+----------+-----+
2 rows in set (0.00 sec)

mysql> select * from pw_luck limit 2,2;
+-----+-------+------+
| uid | name  | msg  |
+-----+-------+------+
|   2 | lisi  | 1001 |
|   3 | wang5 | 1001 |
+-----+-------+------+
2 rows in set (0.00 sec)

　　3.排序 

　　数据排序  select * from pw_luck order by name

　　多行排序  select * from pw_luck order by name，msg

　　升序，降序排列  select * from pw_luck order by name desc(降序)

　　　　　　　　　　 select * from pw_luck order by name asc（升序，默认不写也可以），msg desc

　　4.where 语句 过滤数据

mysql> select * from pw_luck where name='wang5';
+-----+-------+------+
| uid | name  | msg  |
+-----+-------+------+
|   3 | wang5 | 1001 |
|  10 | wang5 | 1000 |
+-----+-------+------+
2 rows in set (0.00 sec)

　　不匹配检查：<>

mysql> select * from pw_luck where msg <> 1000;
+-----+----------+------+
| uid | name     | msg  |
+-----+----------+------+
|   0 | Wilson   |  100 |
|   1 | zhangsan |  100 |
|   2 | lisi     | 1001 |
|   3 | wang5    | 1001 |
+-----+----------+------+
4 rows in set (0.00 sec)

　　between ... and... 范围检查

mysql> select * from pw_luck where msg between 1 and 1000;
+-----+-----------+------+
| uid | name      | msg  |
+-----+-----------+------+
|   0 | Wilson    |  100 |
|   1 | zhangsan  |  100 |
|   7 | zhangsan7 | 1000 |
|   8 | zhangsan8 | 1000 |
|   9 | zhangsan9 | 1000 |
|  10 | wang5     | 1000 |
+-----+-----------+------+
6 rows in set (0.00 sec)

   null 空置检查 

select * from pw_luck where name is not null;

select * from pw_luck where name is null;

mysql> select * from pw_luck where name is not null;
+-----+-----------+------+
| uid | name      | msg  |
+-----+-----------+------+
|   0 | Wilson    |  100 |
|   1 | zhangsan  |  100 |
|   2 | lisi      | 1001 |
|   3 | wang5     | 1001 |
|   7 | zhangsan7 | 1000 |
|   8 | zhangsan8 | 1000 |
|   9 | zhangsan9 | 1000 |
|  10 | wang5     | 1000 |
+-----+-----------+------+
8 rows in set (0.00 sec)

 　5.组合语句：

　　and  or 操作符

　　select * from pw_luck where name is not null and msg <2000;

　　select * from pw_luck where name = 'wang5'or msg <1000;

　　and 计算优先级别高于 or 必要时候加上括号

mysql> select * from pw_luck where name = 'wang5'or msg <1000 and uid >3;
+-----+-------+------+
| uid | name  | msg  |
+-----+-------+------+
|   3 | wang5 | 1001 |
|  10 | wang5 | 1000 |
+-----+-------+------+
2 rows in set (0.10 sec)

mysql> select * from pw_luck where (name = 'wang5'or msg <1000 ) and uid >3;
+-----+-------+------+
| uid | name  | msg  |
+-----+-------+------+
|  10 | wang5 | 1000 |
+-----+-------+------+
1 row in set (0.01 sec)

　　in 操作符

　　select * from pw_luck where msg in (1000,1001);

　　not 操作符:否定气候的任何条件

mysql> select * from pw_luck where msg not in (1000,1001);
+-----+----------+-----+
| uid | name     | msg |
+-----+----------+-----+
|   0 | Wilson   | 100 |
|   1 | zhangsan | 100 |
+-----+----------+-----+
2 rows in set (0.00 sec)

　　6.通配符过滤 like

　　%任何字符出现的次数(不匹配null)

　　_任何单个字符

mysql> select * from pw_luck where name like 'wang%' or name like 'zhang%';
+-----+-----------+------+
| uid | name | msg |
+-----+-----------+------+
| 1 | zhangsan | 100 |
| 3 | wang5 | 1001 |
| 7 | zhangsan7 | 1000 |
| 8 | zhangsan8 | 1000 |
| 9 | zhangsan9 | 1000 |
| 10 | wang5 | 1000 |
| 11 | wang5% | 2000 |
+-----+-----------+------+
7 rows in set (0.00 sec)

  escape 查询条件中包含通配符用 escape 过滤通配符

  如下：M代表转字符将后面的%转义为普通% 等价于 搜索 包含wang5%的条件

mysql> select * from pw_luck where name like 'wang5M%' escape 'M';
+-----+--------+------+
| uid | name   | msg  |
+-----+--------+------+
|  11 | wang5% | 2000 |
+-----+--------+------+
1 row in set (0.00 sec)