Error using minus operator

Question

table a
=========
id (number),name varchar2,dt date
10,'aaa','01-01-2006'
11,'bbb','01-01-2007'
table b
======================
id varchar2,name varchar2,dt varchar2
'10','aaa','01-01-2006'
is it possible to find out which row is not in table b but it is in table a
i have tried out using minus operator but it return error (ora-01790-expression must have same datatype.

Answer 1

ora-01790-expression must have same datatypeAnd what is it precisely is it about that error message which is confsuing you?
SQL> select 1 from dual
  2  minus
  3  select dummy from dual
  4  /
select 1 from dual
ERROR at line 1:
ORA-01790: expression must have same datatype as corresponding expression
SQL> select to_char(1) from dual
  2  minus
  3  select dummy from dual
  4  /
T
1
SQL> Cheers, APC