// insertStamkund takes six strings as input and calls randomNumber for an integer
public int insertStamkund(
String pnrParam,
String fnameParam,
String snameParam,
String addrParam,
String mailParam,
String cellParam) {
// Call randomNumber() and stores the value to cardParam.
int cardParam = randomNumber(1000, 9999);
// Set the SQL statement into the query variable
String query =
"INSERT INTO Stamkund (kortnummer,personnummer,förnamn,"
+ "efternamn,adress,epost,mobilnummer) VALUES (?,?,?,?,?,?,?)";
try {
// Create a statement associated to the connection and the query.
// The new statement is placed in the variable stmt.
PreparedStatement stmt = con.prepareStatement(query);
// Provide the values for the ?'s in the SQL statement, from 1 to 7.
stmt.setInt(1, cardParam);
stmt.setString(2, pnrParam);
stmt.setString(3, fnameParam);
stmt.setString(4, snameParam);
stmt.setString(5, addrParam);
stmt.setString(6, mailParam);
stmt.setString(7, cellParam);
// Execute the SQL statement that is prepared in the variable stmt
stmt.executeUpdate();
// Close the variable stmt and release all resources bound to it
stmt.close();
// Commit the changes made to the database.
con.commit();
} catch (Exception e) {
e.printStackTrace();
System.out.println("Error on Data Insert");
}
// Returns card number for user display
return cardParam;
}
// Method for generating and returning a randomized card number in the range of 1000-9999.
// The range can be edited in the insertStamkund method.
public int randomNumber(int min, int max) {
// Local variables
String query;
ResultSet rs;
PreparedStatement stmt;
int internalNumber;
// A random number is generated in the selected range min-max (1000-9999)
Random rand = new Random();
internalNumber = rand.nextInt((max - min) + 1) + min;
try {
// Set the SQL statement into the query variable
// We check if our generated number exists in the database.
query = "SELECT kortnummer FROM Stamkund WHERE kortnummer = ?";
stmt = con.prepareStatement(query);
stmt.setInt(1, internalNumber);
// Execute the SQL statement that is prepared in the variable stmt
// and store the result in the variable rs.
// If we receive a ResultSet, boolean result is set to 1, and the generated number exists.
rs = stmt.executeQuery();
boolean result = rs.next();
// If result is true, we call ourselves for a new number
if (result) {
return randomNumber(min, max);
}
// Close the variable stmt and release all resources bound to it
stmt.close();
} catch (Exception e) {
e.printStackTrace();
System.out.println("Data Insert error");
}
// If result is false, returns the unique card number
return internalNumber;
}