Append user input to a database

This is my first time writing a Swing+Groovy application that successfully inserts data to SQL tables. It may look like example code, but it is more test code, as I will eventually expand this to a much bigger application, and would like to see if I can improve it before expanding it.

What it does when you run it is bring up an input window, like this:

And (for now) after you click submit, it will print this to the console:

You entered:
First name: John
Last name: Smith
Phone: (111) 123-4567
Date of birth: 1980-06-28

Sql Instance: groovy.sql.Sql@1383c410

New data appended to table:
Person Id: 1
Name: John Smith
Phone: (111) 123-4567
Date of birth: 1980-06-28

How can I improve this?

```
/**
* @author github.com/Phrancis
*/
import groovy.sql.Sql
import groovy.swing.SwingBuilder
import java.awt.*

/**
* SQL queries to be called by the Swing application.
* @TODO: Extract queries to a separate file
*/
def createTestTable = """
START TRANSACTION;
DROP TABLE IF EXISTS test;
CREATE TABLE test (
id SERIAL,
first_name TEXT,
last_name TEXT,
phone TEXT,
date_of_birth DATE
);
COMMIT;"""

def insertQuery = """
START TRANSACTION;
INSERT INTO test (first_name, last_name, phone, date_of_birth)
VALUES ( ?, ?, ?, CAST(? AS DATE) );
COMMIT;"""

/**
* Define input field variables.
*/
class UserInput {
String firstName
String lastName
String phone
String dateOfBirth
}

/**
* Initialize values for input fields.
*/
def userInput = new UserInput(
firstName: null,
lastName: null,
phone: null,
dateOfBirth: null)

/**
* Swing application starts here.
*/
def swingBuilder = new SwingBuilder()
swingBuilder.edt {

// style of form
lookAndFeel 'nimbus'

// outer frame size
def width = 400
def height = 300

// outer frame
frame (title: 'User information',
s

This drops the table every time you start the application, so previous data is removed,

DROP TABLE IF EXISTS test;

Are you sure this is what you really want?

I hope you know what you're doing here, so that you're aware of that.

def userInput = new UserInput(
        firstName: null,
        lastName: null,
        phone: null,
        dateOfBirth: null)

The fields of UserInput are automatically initialized to null, this can be simply:

def userInput = new UserInput()

You extracted variables/constants for width and height, but not for columns? You have the following lines in your code:

td { textField id:'firstName', columns: 20 }
td { textField id:'lastName', columns: 20 }
td { textField id:'phone', columns: 20 }
td { textField id:'dateOfBirth', columns: 20 }

In case you'd ever want to change the columns on all at once, I'd recommend extracting a constant for that.

This looks slightly ugly:

bean userInput, firstName: bind { firstName.text }
bean userInput, lastName: bind { lastName.text }
bean userInput, phone: bind { phone.text }
bean userInput, dateOfBirth: bind { dateOfBirth.text }

It can be written as:

bean userInput,
    firstName: bind { firstName.text },
    lastName: bind { lastName.text },
    phone: bind { phone.text },
    dateOfBirth: bind { dateOfBirth.text }

Overall, very nicely done. I'd recommend you to implement the TODO things, and then get back for another review.

StackExchange Code Review Q#95050, answer score: 3