Question

I have a following table:

bid | data
1   | a
1   | b
1   | c
2   | a
3   | c
3   | a

I want to select all bids that contain given set of data.

For example, all bids that ‘contains’ data “a” and “b” (result should be bid 1), or ones that contain “a” and “c” (1 and 3).

Only solution I could think of is kind of nasty, so I would appreciate some help/suggestions.

My first try:

select bid from my_table as t1 where 
exists (select * from my_table t2 where 
    t2.bid = t1.bid and 
    t2.data='a'
)
and
exists (select * from my_table t2 where 
    t2.bid = t1.bid and 
    t2.data='b'
)
group by bid;

Thanks.

Answer 1

select t1.bid
from table_1 t1
inner join table_1 t2 on t1.bid = t2.bid
where t1.data = 'a' and t2.data = 'c'

By the way:

all bids that ‘contains’ data “a” and “b” (result should be bid 1)

–> bid 2 also contains data ‘a’ and ‘b’