Select with not exist in the same table with multiple fields - sql

Question

I need to select registers from table that not exist in the same table. I mean if i have this table:
ID VALUE1 VALUE2 VALUE3
1 1 1 1
2 2 2 1
3 3 4 1
4 1 5 1
5 2 2 2
6 3 4 2
7 1 8 2
8 2 2 2
The result of the query should be
ID VALUE1 VALUE2 VALUE3
1 1 1 1
4 1 5 1
Because the rest of the values are the same for the value1 and value2 but diferent value3. I mean the row 2 of the table is the same that the row 5.
I try to do something like but not works:
select t1.value1, t1.value2 from table1 t1 where value3=1
and not exist
(select t2.value1, t2.value2 from table2 t2
where t1.value1=t2.value1 and t1.value2=t2.value2 and value3=2)
Thank you in advise and sorry for my english

Answer 1

You can use the NOT EXISTS as follows:
SELECT *
FROM YOUR_TABLE T1
WHERE T1.VALUE3 = 1
AND NOT EXISTS
(SELECT 1
FROM YOUR_TABLE T2
WHERE T1.VALUE1 = T2.VALUE1
AND T1.VALUE2 = T2.VALUE2)

Answer 2

I think not exists does what you want:
select t1.*
from table1 t1
where t1.value3 = 1 and
not exist (select 1
from table2 t2
where t2.value1 = t1.value1 and
t2.value2 = t1.value2 and
t2.value3 = 2
);
That said, you can also use window functions:
select t1.*
from (select t1.*,
max(value3) over (partition by value1, value2) as max_value3
from table1 t1
where value3 in (1, 2)
) t1
where max_value3 = 1;

Answer 3

I think that you are on the right track with exists.
I would phrase your query like:
select t1.*
from table1 t1
where
t1.value3 = 1
and not exist (
select 1 from table1 t2
where t1.value1 = t2.value1 and t1.value2 = t2.value2 and t2.value3 = 2
)
Key points:
the exists subquery should be from table1 (your query uses table2 but it seems like this table does not actually exists)
you don't actually need to return columns from the exists subquery, since all it does is check if some row is produced - hence the select 1