import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class MSsqlDatabase implements Main.DatabaseGateway {

    private static Connection connection;
    private Statement statement;

    public MSsqlDatabase() {
        if (connection == null) {
            String jdbcUrl = ""; //jdbc:sqlserver://localhost;databaseName=<databaseName>;
            String username = "";
            String password = "";
            String driverClassName = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
            try {
                Class.forName(driverClassName);
                connection = DriverManager.getConnection(jdbcUrl, username, password);
            } catch (ClassNotFoundException | SQLException e) {
                e.printStackTrace();
            }
        }

    }

    public List<String> getStudentNames() {
        List<String> names = new ArrayList<String>();
        ResultSet resultSet;
        try {
            statement = connection.createStatement();
            resultSet = statement.executeQuery("select name from student");
            while (resultSet.next()) {
                names.add(resultSet.getString(1));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return names;
    }
}