How to fetch single records using case statements

CREATE TABLE test_table (
    e_id     NUMBER(10),
    e_value  NUMBER(10)
);

INSERT INTO test_table VALUES(11,123);
INSERT INTO test_table VALUES(11,123);
INSERT INTO test_table VALUES(11,null);

COMMIT;

I want to fetch single record from the table test_table if any one of the value is null in the column e_value then it should print No else Yes

My Attempt:

SELECT e_id,
CASE 
WHEN e_value IS NULL THEN 'No'
ELSE 'Yes'
END is_answer
FROM test_table;

Current Output:

+------+-----------+
| e_id | is_answer |
+------+-----------+
|   11 | Yes       |
|   11 | Yes       |
|   11 | No        |
+------+-----------+

Expected Output:

+------+-----------+
| e_id | is_answer |
+------+-----------+
|   11 | No        |
+------+-----------+

Answer

you can use GROUP BY and COUNT:

SELECT e_id,
CASE 
WHEN count(e_id) = count(e_value) THEN 'Yes'
ELSE 'No'
END is_answer
FROM test_table
GROUP BY e_id;

The count will return number of non-null values

db<>fiddle here