Mysql中判断是否存在

不能像sqlserver一样用if not exists或者exists，应该这样：

DECLARE p_count int;

set p_count=0;

select 1 into p_count FROM    basic_Character  WHERE   AreaName = p_areaName

                                    AND AccountName = p_accountName

                                    AND CharacterName = p_characterName  limit 1;

if p_count=1 then

....

else ....

end if;