テーブル構造を考えると、カイの答えは正しいです。
将来的には、次のような実際のリレーショナル モデルを使用することをお勧めします。
CREATE TABLE QUESTION(
ID INTEGER NOT NULL,
QUESTION VARCHAR(100) NOT NULL,
PRIMARY KEY (ID)
);
INSERT INTO QUESTION VALUES(1, 'My first question');
INSERT INTO QUESTION VALUES(2, 'My second question');
INSERT INTO QUESTION VALUES(3, 'My third question');
CREATE TABLE ANSWER(
ID INTEGER NOT NULL,
ID_QUESTION INTEGER NOT NULL,
ANSWER VARCHAR(100) NOT NULL,
PRIMARY KEY (ID),
FOREIGN KEY (ID_QUESTION) REFERENCES QUESTION(ID)
);
INSERT INTO ANSWER VALUES (1, 1, 'First possible answer for question 1');
INSERT INTO ANSWER VALUES (2, 1, 'Second possible answer for question 1');
INSERT INTO ANSWER VALUES (3, 1, 'Third possible answer for question 1');
INSERT INTO ANSWER VALUES (4, 2, 'First possible answer for question 2');
INSERT INTO ANSWER VALUES (5, 2, 'Second possible answer for question 2');
INSERT INTO ANSWER VALUES (6, 3, 'First possible answer for question 3');
INSERT INTO ANSWER VALUES (7, 3, 'Second possible answer for question 3');
INSERT INTO ANSWER VALUES (8, 3, 'Third possible answer for question 3');
INSERT INTO ANSWER VALUES (9, 3, 'Fourth possible answer for question 3');
SELECT
QUESTION.ID,
COUNT(*) as NB_ANSWER
FROM QUESTION
INNER JOIN ANSWER ON QUESTION.ID = ANSWER.ID_QUESTION
GROUP BY QUESTION.ID
ORDER BY QUESTION.ID;
ここで動作することを確認してください:http://sqlfiddle.com/#!3/0025a/3/0