修改數據庫字符集：

ALTER DATABASE db_name DEFAULT CHARACTER SET character_name [COLLATE …];

把表默認的字符集和所有字符列（CHAR,VARCHAR,TEXT）改為新的字符集：

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

此處寫utf8_general_ci有時候會報錯，直接寫utf8即可

alter table logtest convert to character set utf8;

只是修改表的默認字符集：

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;

查看數據庫編碼：

SHOW CREATE DATABASE db_name;

查看表編碼：

SHOW CREATE TABLE tbl_name;

查看字段編碼：

SHOW FULL COLUMNS FROM tbl_name;

mysql修改表、字段、庫的字符集