ALTER TABLE `table` DEFAULT CHARACTER SET utf8;
但是虽然修改了表的编码格式，但是字段的编码格式并没有修改过来，没有什么卵用
又发现一条语句，作用是修改字段的编码格式
ALTER TABLE `tablename` CHANGE `字段名1` `字段名2` VARCHAR(36) CHARACTER SET utf8 NOT NULL;
最后找到这么一条语句
alter table `tablename` convert to character set utf8;
它可以修改一张表的所有字段的编码格式，顿时方便多了
Ps ：延伸一下，修改mysql中所有表，所有字段编码，需要用到存储过程
转换表字段编码的sql语句为：alter table `tableName` convert to character set utf8\'
CREATE PROCEDURE `pr_convert_dbtab_utf8`(IN dbName varchar(100))
BEGIN
declare stop int default 0;
declare tabCount int default 0;
declare strSql varchar(1000);
declare name varchar(100);
declare cur CURSOR FOR select table_name from information_schema.tables where table_schema=dbName;
declare CONTINUE HANDLER FOR SQLSTATE \'02000\' SET stop = null;
OPEN cur;
FETCH cur INTO name;
WHILE ( stop is not null) DO
set tabCount=tabCount+1;
set strSql = concat(\'alter table `\',name,\'` convert to character set utf8\');
set @sql1 = strSql;
prepare stmt_p from @sql1;
execute stmt_p;
FETCH cur INTO name;
END WHILE;
CLOSE cur;
SELECT concat(\'table: \', tabCount);
END;
输入调用存储过程的命令，参数为需要转换的数据库名
mysql> call pr_convert_dbtab_utf8(\'jiradb\');
+-----------------------------+
| concat(\'table: \', tabCount) |
+-----------------------------+
| table: 245 |
+-----------------------------+
1 row in set
Query OK, 0 rows affected
mysql>