Question

Given the nums table:

id | num
---+----
1  | 1
2  | null
3  | 2
2  | null
3  | 5
3  | 7

Which of the following queries will return exactly 3 records in a result set? Select all that apply.

Cosmo · Accepted Answer

SELECT 3 FROM nums;

will return 6 records consisting of number "3".

SELECT id FROM nums;

will return all ids from the table (6 records).

SELECT num FROM nums WHERE num IS NOT NULL;

will return 6 records.

SELECT COUNT(DISTINCT id) FROM nums;

will return 1 record containing "3" in it.

SELECT DISTINCT id FROM nums WHERE num IS NOT NULL;

will return only 2 records.

Cosmo · Accepted Answer

SELECT DISTINCT id FROM nums;

Cosmo · Accepted Answer

SELECT * FROM nums WHERE id <> num;

Cosmo · Answer

SELECT 3 FROM nums;

Cosmo · Answer

SELECT id FROM nums;

Cosmo · Answer

SELECT num FROM nums WHERE num IS NOT NULL;

Cosmo · Answer

SELECT COUNT(DISTINCT id) FROM nums;

Cosmo · Answer

SELECT DISTINCT id FROM nums WHERE num IS NOT NULL;