修改数据库字符集：

ALTER DATABASE db_name DEFAULT CHARACTER SET character_name [COLLATE ...];   
把表默认的字符集和所有字符列（CHAR,VARCHAR,TEXT）改为新的字符集：

ALTER TABLE tbl_name CONVERT TO CHARACTER SET character_name [COLLATE ...]  
如：ALTER TABLE logtest CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci; 

只是修改表的默认字符集：

ALTER TABLE tbl_name DEFAULT CHARACTER SET character_name [COLLATE...];  
如：ALTER TABLE logtest DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci; 


修改字段的字符集：

ALTER TABLE tbl_name CHANGE c_name c_name CHARACTER SET character_name [COLLATE ...];  
如：ALTER TABLE logtest CHANGE title title VARCHAR(100) CHARACTER SET utf8 COLLATE utf8_general_ci; 


查看数据库编码：
SHOW CREATE DATABASE db_name; 
  
查看表编码：
SHOW CREATE TABLE tbl_name;   

查看字段编码：
SHOW FULL COLUMNS FROM tbl_name;   

名称栏目：MySQL表、字段、库的字符集修改方法介绍
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