MYSQL5.6 字符串删除中文

select
     replace(convert(info using ascii),"?","") as info_fix
    ,convert(info using ascii) as info_fix2
    ,substring_index(substring_index(INFO,'\n',2),'\n',-1) as info_fix3
    ,case 
        when substring_index(TRIM(info),' ',1) = 'select'  then TRIM(info) -- 第一行有select
        when substring_index(TRIM(info),' ',1) = 'select*' then TRIM(info) -- 第一行有select
        when substring_index(convert(TRIM(info) using ascii),'\n',1) regexp '\\?' then substring_index(substring_index(INFO,'\n',2),'\n',-1) -- 第一行有中文
        when substring_index(convert(TRIM(info) using ascii),'\n',2) regexp '\\?' then substring_index(substring_index(INFO,'\n',3),'\n',-1) -- 第二行有中文
        when substring_index(convert(TRIM(info) using ascii),'\n',3) regexp '\\?' then substring_index(substring_index(INFO,'\n',4),'\n',-1) -- 第三行有中文
        else substring_index(INFO,'\n',1)
    end as flag
from monitor_processlist_killed_log 
where id = '16470310'
\G