Create and persist properly in the MySQL database - mysql

Question

I work with a Spring boot application and this is the entity class I work,
#Entity
public class User {
// form:hidden - hidden value
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
// form:input - textbox
#Column(name = "name", columnDefinition = "VARCHAR(30)", nullable = false)
String name;
// form:input - textbox
#Column(name = "email", columnDefinition = "VARCHAR(50)", nullable = false)
String email;
// form:input - password
#Column(name = "password", columnDefinition = "VARCHAR(20)", nullable = false)
String password;
// form:textarea - textarea
#Column(name = "address", columnDefinition = "VARCHAR(255)")
String address;
// form:input - password
String confirmPassword;
// form:checkbox - single checkbox
#Column(name = "newsletter")
boolean newsletter;
// form:radiobutton - radio button
#Column(name = "sex", columnDefinition = "VARCHAR(1)")
String sex;
// form:radiobuttons - radio button
#Column(name = "number")
Integer number;
// form:select - form:option - dropdown - single select
#Column(name = "country", columnDefinition = "VARCHAR(10)")
String country;
// form:checkboxes - multiple checkboxes
#ElementCollection
#NotNull
List<String> framework;
// form:select - multiple=true - dropdown - multiple select
#ElementCollection
List<String> skill;
}
I intend to only create the following columns in the user table,
id,
name,
email,
address,
password,
newsletter,
framework,
sex,
Number,
Country,
Skill
For example, the corresponding SQL will be like (though I don't want to write explicitly),
CREATE TABLE user (
id LONG GENERATED BY DEFAULT AS IDENTITY(START WITH 1, INCREMENT BY 1) PRIMARY KEY,
name VARCHAR(30),
email VARCHAR(50),
address VARCHAR(255),
password VARCHAR(20),
newsletter BOOLEAN,
framework VARCHAR(500),
sex VARCHAR(1),
Number INTEGER,
Country VARCHAR(10),
Skill VARCHAR(500)
);
The starting controller class,
#Controller
public class UserController {
private final Logger logger = LoggerFactory.getLogger(UserController.class);
#Autowired
private UserService userService;
private static List<User> populateDefaultUserValues() {
List<User> users = new ArrayList<>();
User user = new User();
user.setName("Ella");
user.setEmail("xyz#gmail.com");
user.setPassword("df32d343H");
user.setFramework(Arrays.asList("Spring MVC, GWT".split("\\s*,\\s*")));
users.add(user);
user = new User();
user.setName("Alex");
user.setEmail("alex#hotmail.com");
user.setPassword("12HH2d343H");
user.setFramework(Arrays.asList("Spring MVC, GWT".split("\\s*,\\s*")));
users.add(user);
user = new User();
user.setName("Romanna");
user.setEmail("romanna#hotmail.com");
user.setPassword("Rommann343");
user.setFramework(Arrays.asList("Spring MVC, GWT".split("\\s*,\\s*")));
users.add(user);
return users;
}
#GetMapping(value = "/")
public String index() {
return "redirect:/users";
}
#GetMapping(value = "/users")
public String showAllUsers(Model model) {
List<User> users = populateDefaultUserValues();
users.forEach(user -> {
userService.save(user);
});
model.addAttribute("users", userService.findAll());
return "list";
}
}
When I run the app, I see that this created in the MYSQL database,
How do I omit the confirmed_password field and add the columns of skill and framework? I expect them to be VARCHAR?

Answer 1

How do I omit the confirmed_password field
You should use the #Transient annotation.
add the columns of skill and framework?
Since you've marked them as #ElementCollection - there will be no columns in user table, as you can't persist a collection of values in a single relation attribute (it would violate 1NF restrictions). There are two additional tables, named like user_framework and user_skill, they are related to user table with user_id columns.
You may read the Java Persistense wiki and the Hibernate documentation about collections to find different examples of proper usage. Although, your code is fine and, in common case, you should not worry about database tables, relations and data consistency - ORM framework (Hibernate, by default) will handle all these things for you.