eate Database |
+----------+----------------------------------------------------------------+
| db2 | CREATE DATABASE `db2` /*!40100 DEFAULT CHARACTER SET latin1 */ |
+----------+----------------------------------------------------------------+
1 row in set (0.00 sec)
修改库的字符集
mysql> alter database db2 default character set utf8;
Query OK, 1 row affected (0.00 sec)
mysql> show create database db2;
+----------+--------------------------------------------------------------+
| Database | Create Database www.2cto.com |
+----------+--------------------------------------------------------------+
| db2 | CREATE DATABASE `db2` /*!40100 DEFAULT CHARACTER SET utf8 */ |
+----------+--------------------------------------------------------------+
1 row in set (0.00 sec)
B.表字符集
mysql> use db2;
Database changed
使用默认库字符集的表
mysql> create table t1(a varchar(10));
Query OK, 0 rows affected (0.01 sec)
mysql> show create table t1;
+-------+-----------------------------------------------------------------------------------------+
| Table | Create Table |
+-------+-----------------------------------------------------------------------------------------+
| t1 | CREATE TABLE `t1` (
`a` varchar(10) default NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 |
+-------+-----------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
创建指定字符集的表
mysql> create table t2(a varchar(10)) default character set latin1;;
Query OK, 0 rows affected (0.01 sec)
ERROR:
No query specified
mysql> show create table t2;
+-------+-------------------------------------------------------------------------------------------+
| Table | Create Table |
+-------+-------------------------------------------------------------------------------------------+
| t2 | CREATE TABLE `t2` (
`a` varchar(10) default NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+-------+-------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
更改表的字符集
mysql> alter table t2 default character set utf8;
Query OK, 0 rows affected (0.01 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> show create table t2;
+-------+--------------------------------------------------------------------------------------------------------------+
| Table | Create Table www.2cto.com |
+-------+--------------------------------------------------------------------------------------------------------------+
| t2 | CREATE TABLE `t2` (
`a` varchar(10) character set latin1 default NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 |
+-------+--------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
mysql>
从上面可以看到，修改表的字符集时，不会影响已经存在列的字符集，但新增列将继承表的字符集，如下
mysql> alter table t2 add a2 varchar(10);
Query OK, 0 rows affected (0.01 sec)
Records: 0 Duplicates: 0 Warnings: 0
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