SQL Oracle - display values only once per column -

i'm trying format select statement. assignment specifies has formatted way.

i have database regarding taxi service. have put view company name, passenger name, , taxi number. easy. however, output specifies company name should appear once in output, @ top of it's own group. have:

create view taxitrips(companyname, passengername, taxi#) (select company.name, booking.name, vehicles.taxi# booking join vehicles on booking.taxi# = vehicles.taxi# right outer join company on vehicles.name = company.name); 

the right outer join companies no booking recorded still displayed. if run:

select * taxitrips order companyname asc; 

it give me like

companyname          passengername      taxi# --------------------------------------------- abc taxis            dave                192 legion cabs premier cabs         shane               2154 premier cabs         tim                 2169 silver service       dave                18579 silver service       tim                 18124 silver service       aaron               18917 

no result legion cabs, field displayed, et cetera. assignment specification says has this.

companyname          passengername      taxi# --------------------------------------------- abc taxis            dave                192 legion cabs premier cabs         shane               2154                      tim                 2169 silver service       dave                18579                      tim                 18124                      aaron               18917 

the company name should displayed on first row. distinct not helping. advice?

normally, @ application layer, because result set relies on ordering of rows -- bad thing in sql.

but can as:

select (case when row_number() on (partition c.name order v.taxi#) = 1              c.name         end) companyname, b.name, v.taxi# company c left join      vehicles v      on v.name = c.name left join      booking b       on b.taxi# = v.flight# order c.name, v.taxi#; 

note: rearranged joins left joins. people find easier follow right joins.