sql - Oracle Procedure Escape characters -

i stuck escape characters give different values.please me solve problem.please me why same query giving different results.

query :

select * app_realm_entries id in (select id app_entries app_ext_code ='ttl1' , version_number='1.0.1'); 

result : single row result comes

sql block :

declare  appcode varchar2(20); version_number varchar2(20); type rc ref cursor; table_cursor rc; rec_table realm_entries%rowtype; begin appcode := 'ttl1'; version_number := '1.0.1'; open table_cursor 'select * realm_entries id in (select id app_entries app_ext_code ='''||appcode||''||'and version_number='||version_number||''')'; loop     fetch table_cursor rec_table;     dbms_output.put_line('rowcount ' ||  table_cursor%rowcount );      exit when table_cursor%notfound;   end loop;    close table_cursor; end; 

result : rowcount 0

as justin suggested use bind variables. you'll achieve 2 things doing that, won't need worry getting number of quotes correct, , more importantly, you'll close door sql injection vulnerabilities. can changing open statement following:

open table_cursor 'select * realm_entries id in (select id app_entries app_ext_code =:appcode , version_number=:version_number)' using appcode, version_number;