SQLでのCROSS JOINとINNER JOINの比較
違いは何であるCROSS JOINとはINNER JOIN? CROSS JOIN: SELECT Movies.CustomerID, Movies.Movie, Customers.Age, Customers.Gender, Customers.[Education Level], Customers.[Internet Connection], Customers.[Marital Status], FROM Customers CROSS JOIN Movies 内部結合: SELECT Movies.CustomerID, Movies.Movie, Customers.Age, Customers.Gender, Customers.[Education Level], Customers.[Internet Connection], Customers.[Marital Status] FROM Customers INNER JOIN Movies ON Customers.CustomerID = Movies.CustomerID どちらが良いですか、なぜどちらを使用するのですか?