I have a "server" table which has a column named 'SN' in mysql, when do query to retrive servers with some sns from 'sn1' to 'sn10000', we can: select * from server where sn in ('sn1','sn2','sn3',...'sn10000'); If there is only one sn in 'sn1'-'sn10000' which not exists in database, then the query above will retrive 9999 rows of result. The question is how can I easily get which one in 'sn1'-'sn10000' is not exists in database except the additional work, such as handling the result with shell script etc. I have an ugly sql like below can use: select * from (select 'sn1' as sn union select 'sn2' union select 'sn3' .... union select 'sn10000') as SN where not exists (select id from server where server.sn=SN.sn); Is Anyone has other better methods? Thanks.