Updating an object

In this recipe, we will add a DAO method to update an existing row in the database with an object's fields.

How to do it…

Use an SQL update query and execute it using the update() method:

public void update(User user) {
  String sql = "update user set first_name=?, age=? where id=?";
  jdbcTemplate.update(sql, user.getFirstName(), user.getAge(), user.getId());
}

There's more…

It's convenient to also have a save() method that will create the database row if it doesn't exist:

public void save(User user) {
  if (user.getId() == null) {
    add(user);
  }
  else {
    update(user);
  }
}