将某个MySQL库中的UTF8字符列都转成GBK格式
 
DELIMITER $$

DROP PROCEDURE IF EXISTS `dba`.`Proc_ChangeCharacter2GBK`$$

CREATE DEFINER=`root`@`%` PROCEDURE ` Proc_ChangeCharacter2GBK`(in DATABASENAME varchar(20))
BEGIN
    DECLARE done INT DEFAULT 0;
    DECLARE a VARCHAR(64) DEFAULT '';
    DECLARE b VARCHAR(64) DEFAULT '';
    DECLARE c VARCHAR(64) DEFAULT '';
    DECLARE d VARCHAR(64) DEFAULT '';
    DECLARE l_sql VARCHAR(500);
    
    DECLARE AlterColumnsCharacter CURSOR FOR 
           SELECT TABLE_SCHEMA,TABLE_NAME,COLUMN_NAME,COLUMN_TYPE 
           FROM information_schema.COLUMNS 
           WHERE TABLE_SCHEMA=DATABASENAME 
                and TABLE_NAME in (  SELECT B.TABLE_NAME FROM information_schema.TABLES B
                                                          WHERE B.TABLE_SCHEMA=DATABASENAME  AND B.TABLE_TYPE='BASE TABLE' )  
                and COLUMN_TYPE like '%VARCHAR%' and CHARACTER_SET_NAME='utf8' and COLLATION_NAME='utf8_general_ci';

    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done=1;
  
    OPEN AlterColumnsCharacter;
  
    REPEAT  FETCH AlterColumnsCharacter INTO a,b,c,d;

    if(done = 0) then 
      SET l_sql=CONCAT(' alter table ',a, '.',b,' change ',c,' ',c,' ',d,' character set gbk collate gbk_chinese_ci NULL; '); 
      SET @sql=l_sql;
      PREPARE s1 FROM @sql;
      EXECUTE s1;
      DEALLOCATE PREPARE s1;
    end if;
    
   
    UNTIL done 
    END REPEAT;
    CLOSE AlterColumnsCharacter;
    END$$

DELIMITER ;