17 digit number display error

[denofevil]

Oracle Database 19c Enterprise Edition (same error for 12c version, Win/Linux)
PL/SQL Developer
Version 14.0.2.1969 (64 bit)
Windows 10 Build 19041

create table tab(n number(28,10));
insert into tab values (12345678901234567);
commit;
select n from tab; --displays wrong result: 12345678901234602,0000000000
select to_char(n) from tab; --displays correct result: 12345678901234567

 

[Marco Kalter]

For the SQL Window you might try to enable the "Number fields to_char" option (Preferences > SQL Window). Now all numbers will be fetched as character fields with full Oracle precision.