fields_in="email"
fields_out="@usr"
file="/tmp/ca.csv"
table="table"
              
echo "exporting $fields_in from $table"
mysql -u in -N << eof
  select $fields_in
  from $table                                                                                                                                
    into outfile '$file'                                                                                                                         
    fields enclosed by '"' terminated by ';' escaped by '"'
    lines terminated by '\r\n';
eof
[[ $? != 1 ]] || exit
  
echo "importing $fields_out from $file"
mysql -u out << eof
  load data infile '$file' ignore into table usrs 
    fields enclosed by '"' terminated by ';' escaped by '"'
    lines terminated by '\r\n'
    ( $fields_out )
    set id = @id,
      usr = @usr;
eof
[[ $? != 1 ]] || exit