View return nothing

Question

dear gurus i am facing one probelem.
VIEW 1:
create or replace view v_emp as SELECT
a1.empno e1, nvl2(a2.empno,a2.empno,0) e2 from
select empno from emp where
hiredate='17-DEC-80'
) a1,
select empno from emp where
hiredate='20-FEB-81'
) a2;
select * from v_emp;
E1     7369
E2     7499
VIEW 2:
create or replace view v_emp as SELECT
a1.empno e1, nvl2(a2.empno,a2.empno,0) e2 from
select empno from emp where
hiredate='17-DEC-80'
) a1,
select empno from emp where
hiredate='27-FEB-81'
) a2;
select * from v_emp;
return nothing because of date not in table.
i want data from VIEW 2 like
E1     7369
E2     
i want view return nothing or zera for only unavailable date and
return value for date available in table.

Answer 1

901915 wrote:
dear gurus i am facing one probelem.
VIEW 1:
create or replace view v_emp as SELECT
a1.empno e1, nvl2(a2.empno,a2.empno,0) e2 from
select empno from emp where
hiredate='17-DEC-80'
) a1,
select empno from emp where
hiredate='20-FEB-81'
) a2;
select * from v_emp;
E1     7369
E2     7499
VIEW 2:
create or replace view v_emp as SELECT
a1.empno e1, nvl2(a2.empno,a2.empno,0) e2 from
select empno from emp where
hiredate='17-DEC-80'
) a1,
select empno from emp where
hiredate='27-FEB-81'
) a2;
select * from v_emp;
return nothing because of date not in table.
i want data from VIEW 2 like
E1     7369
E2     
i want view return nothing or zera for only unavailable date and
return value for date available in table.your view is a cartesian join between those two select statements. you need to have an outer join or a union all in there somewhere.