Select records not in another table with additional criteria - sql

Question

I am working on an ACCESS DB.
I have 1 table (tblData) with 1 column ( DataId) and 3 entries:
tblData (A)
+--------+
| DataId |
+--------+
| 1 |
| 2 |
| 3 |
+--------+
Another table (tblSelections) contains 3 columns (id, dataid, userid) and has 3 entries:
tblSelections (B)
+----+--------+---------+
| id | dataid | userid |
+----+--------+---------+
| 1 | 1 | 5 |
| 2 | 2 | 5 |
| 3 | 3 | 2 |
+----+--------+---------+
How can I select the records from table A (tblData) which are not in tbl B (tblSelections) for a certain 'userid'?
For 'userid' 5 the query must return 'DataId' 3 from table A as dataid 1 & 2 are already present in table B for userid 5.
For 'userid' 2 the query must return 'DataId' 1 & 2 from table A as dataid 3 is already present in table B for userid 2.
For 'userid' 1 the query must return 'DataId' 1, 2 & 3 from table A as no records are present in table B for userid 1

Answer 1

Use EXISTS or IN for queries like yours:
SELECT *
FROM tblData
WHERE DataId NOT IN
(
SELECT dataid
FROM tblSelections
WHERE userid = 5
);
SELECT *
FROM tblData
WHERE NOT EXISTS
(
SELECT *
FROM tblSelections
WHERE tblSelections.dataid = tblData.DataId AND tblSelections.userid = 5
);

Answer 2

You can use an outer join to select all records, then put a condition in the where clause that a non-nullable column in b is null. This will give you all records in a that do not have a matching row in b according to the join conditions.
This query assumes that you have a parameter or variable named #userid that represents the user ID to search against.
select
a.*
from tblData a
left join tblSelections b on b.dataid = a.dataid and b.userid = #userid
where b.id is null