简单的SQL语句混淆

Question

道歉我知道这一定非常简单，但我对此非常陌生，我在一个简单的选择SQL查询上苦苦挣扎，我有两个表，如下所示。

table 1 quiz
QuizID, ....etc.
Int         

table 2 useranswers
UserAnswersID, QuizID, 
Int             Int         

我只想使用第二个表中的UserAnswersID从第一个表中选择QuizID。我试着写下以下没有运气：

SELECT A.QuizID
FROM quiz Q, useranswers UA
WHERE UA.UserAnswersID = (**int**)

Answer 1

SELECT 
    Q.QuizID
FROM
    quiz Q,
    useranswers UA
WHERE
    UA.UserAnswersID = Q.QuizID;

或者你可以使用JOIN

SELECT 
    Q.QuizID
FROM
    quiz Q
        JOIN
    useranswers UA ON UA.UserAnswersID = Q.QuizID;

Answer 2

SELECT Q.QuizID
FROM quiz Q inner join useranswers UA
on UA.UserAnswersID = Q.QuizID