I updated my question.
I have table like this:
| id | name | contact |
|---|---|---|
| 1 | A | 65489 |
| 1 | A | |
| 1 | A | 45564 |
| 2 | B |
so, i want table like this:
| id | name | contact |
|---|---|---|
| 2 | B |
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Answer
Using exists logic we can try:
SELECT *
FROM yourTable t1
WHERE NOT EXISTS (SELECT 1 FROM yourTable t2
WHERE t2.id = t1.id AND t2.contact IS NOT NULL);
In plain English, the above query says to return any records for which we cannot find another record belonging to the same id group having a non NULL contact value.
Here is a demo of the query.