MariaDB插入中文出现???情况

本来打算创建一个测试表进行一个简单的实验，发现创建完python_test表后插入数据后，select发现所有中文都变成问号了，这一看就是出现了乱码

MariaDB [lhc]> create table python_test(
    -> id int(11),
    -> name varchar(255),
    -> class_time int(11),
    -> PRIMARY KEY(id)
    -> );
Query OK, 0 rows affected (0.03 sec)

MariaDB [lhc]> 

/*插入数据*/
INSERT INTO python_test(id,name,class_time) value(1,'字典',3);
INSERT INTO python_test(id,name,class_time) value(2,'列表',2);
INSERT INTO python_test(id,name,class_time) value(3,'函数',5);
INSERT INTO python_test(id,name,class_time) value(4,'装饰器',2);
INSERT INTO python_test(id,name,class_time) value(5,'迭代器',2);

/*查看数据*/

MariaDB [lhc]> select * from python_test;
+----+-----------+------------+
| id | name      | class_time |
+----+-----------+------------+
|  1 | ??        |          3 |
|  2 | ??        |          2 |
|  3 | ??        |          5 |
|  4 | ???       |          2 |
|  5 | ???       |          2 |
+----+-----------+------------+
5 rows in set (0.00 sec)

首先查看下MariaDB的默认编码格式

MariaDB [lhc]> show variables like "character_set_%"
    -> ;
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8                       |
| character_set_connection | latin1                     |
| character_set_database   | latin1                     |
| character_set_filesystem | binary                     |
| character_set_results    | utf8                       |
| character_set_server     | latin1                     |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+

发现上面的数据库的字符编码不是为utf8

/*修改为utf8编码格式*/

MariaDB [lhc]> set character_set_database=utf8;
Query OK, 0 rows affected (0.00 sec)

/*查看*/
MariaDB [lhc]> show variables like "character_set_%";
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8                       |
| character_set_connection | latin1                     |
| character_set_database   | utf8                       |
| character_set_filesystem | binary                     |
| character_set_results    | utf8                       |
| character_set_server     | latin1                     |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)

查看数据还是问号，说明问题并不出现在数据库中，查看一下连接编码

MariaDB [lhc]> show variables like "collation_%";
+----------------------+-------------------+
| Variable_name        | Value             |
+----------------------+-------------------+
| collation_connection | latin1_swedish_ci |
| collation_database   | latin1_swedish_ci |
| collation_server     | latin1_swedish_ci |
+----------------------+-------------------+
3 rows in set (0.00 sec)

可以发现问题就是出现在连接层。

解决方法

/**/
SET NAMES 'utf8';
/*
它相当于下面的三句指令：
SET character_set_client = utf8;
SET character_set_results = utf8;
SET character_set_connection = utf8;
*/

/**/
/*创建数据库的时候指定编码格式*/
MariaDB [lhc]> create database python_test character set utf8;

/**/
/*创建表的时候指定编码格式*/
MariaDB [lhc]> create table python_test(
    -> id int(11),
    -> name varchar(50) character set utf8,
    -> class_time int(11),
    -> PRIMARY KEY(id)
    -> )DEFAULT CHARSET=utf8;

如果已经创建完成的表或者数据库通过ALTER进行修改

/*修改某一个数据库*/
MariaDB [lhc]> ALTER database python_test character set utf8;

/*修改某一个表*/
MariaDB [lhc]> ALTER table python_test character set utf8;

再次查看原乱码表就不乱码了

MariaDB [lhc]> select * from python_test;
+----+-----------+------------+
| id | name      | class_time |
+----+-----------+------------+
|  1 | 字典       |          3 |
|  2 | 列表       |          2 |
|  3 | 函数       |          5 |
|  4 | 装饰器     |          2 |
|  5 | 迭代器     |          2 |
+----+-----------+------------+