Getting duplicate rows on subquery - sql

Question

So this has been bothering me for some time because I feel like in MSSQL this query would run just fine but at my new job I am forced to use Oracle. I have a subselect in a query where I want to find all of the people not assigned to a survey. My query is as follows:
Select distinct * From GetAllUsers, getperms
Where id not in (getperms.users) and Survey_ID = '1'
If there are three users in the getperms table I get three rows for each person in the the GETALLUsers table.
I guess I could do some kind of join and that's no problem, it's just really bothering me that this doesn't work when i think that it should.

Answer 1

I feel like in MSSQL this query would run just fine
It would not. In both Oracle and MS-SQL, an IN clause needs to be a static list of items or a subquery that returns one column, so you'd need something like:
Select distinct *
From GetAllUsers
Where id not in (SELECT id FROM getperms.users)
and Survey_ID = '1'
Note that I took getperms out of the FROM since it produces a cross-join, which is why you get every combination of records from both tables.

Answer 2

Your query looks just horrible. First of all you are using a join syntax that has become out of date more than twenty years ago. Then you are using NOT IN where it doesn't make sense (your set contains just one value). Then I can hardly imagine that DISTINCT makes sense in your query. Or one of the two tables contains records that are exact duplicates, which it shouldn't. Is Survey_ID really a string? And as you are working with two tables, you should use qualifiers on your columns to indicate where they reside in, e.g. GetAllUsers.id. I assume that Survey_ID resides in getperms.
Your query properly written looks thus:
Select *
From GetAllUsers gau
Join getperms gp On gp.Survey_ID = '1' And gp.users <> gau.id;
But of course whether you write it this way or the other, it does exactly the same. And there is no difference whether you use it in Oracle or SQL Server. What is does is: get all combinations of GetAllUsers and survey-1 getperms, except for the matches. So every user will be in the results, each combined with almost every getperms record.
You say: "I want to find all of the people not assigned to a survey". That would rather be:
Select *
From GetAllUsers
Where id Not In (Select users From getperms Where Survey_ID = '1');

Answer 3

You can use any of the following 3 methods,if you wanted to exclude the getperms users from GetAllUSers .
SELECT DISTINCT a.*
FROM GetAllUsers a
LEFT JOIN getperms b
ON a.id=b.users
WHERE b.users is null AND Survey_ID = '1'
OR
SELECT DISTINCT *
FROM GetAllUsers a
WHERE NOT EXISTS (SELECT 1
FROM getperms b
WHERE a.id=b.users)
AND Survey_ID = '1'
OR
SELECT DISTINCT *
FROM GetAllUsers
WHERE ID NOT IN (SELECT users
FROM getperms )
AND Survey_ID = '1'