Formatting data from a result set with the toString() method

Question

My question is this, what is the most efficient way to use the toString method to format data from a ResultSet?

Here is the method that I have thus far:

public void query()
{
    Statement stmt = null;
    ResultSet rs = null;

    try
    {
        //Create database connection
        Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/registrar",
                "abt1s", "abt1s");
        stmt = conn.createStatement();

        //create SQL statement
        String st = "SELECT * FROM  student WHERE studentID = '" + this.getStudentID() + " '";

        rs = stmt.executeQuery(st);

        String studentData = rs.toString();
        System.out.println(studentData);

        rs.close();
        stmt.close();
        conn.close();
    }catch(Exception e)
            {
                System.err.println("ERROR: Either cannot connect to the DB " + " or error with the SQL statement");
            }

}

Answer 1

You can go row by row through the ResultSet and print whatever you want:

// Fetch each row from the result set
while (rs.next()) {
    // Get the data from the row using the column index
    String s = rs.getString(1);

    // Get the data from the row using the column name
    s = rs.getString("col_string");
}

Answer 2

You need to convert the ResultSet into a Student class before you can use Student.toString to generate the proper output.

"Retrieving and Modifying Values from Result Sets" explains one way of extracting data from a ResultSet .

Alternatively, you can look at an Object-Relational-Mapping (ORM) which eases creating domain objects (like Student ) from database rows. What Java ORM do you prefer, and why? has useful pointers to discussions of the various ORMs and how to get started with them.