Exception Handling on save/update in Spring Boot 3

I have a spring boot 3 project and have been looking into the various ways to deal with uniqueness checks before saving or updating a record. It looks like there is a few approaches, but broadly:

1. Run a pre-save/pre-update check for uniqueness and return a boolean
Cons here are : not atomic, not concurrent safe and extra db call
2. Let the db throw the exception and have it handled in Spring

I am mainly interested in the best way to implement #2. This is what I have so far

ENTITY
@Entity @SequenceGenerator(name = "car_seq", sequenceName = "car_SEQ", initialValue = 100, allocationSize = 50) @Table(name = "car", uniqueConstraints = {        @UniqueConstraint(name="uc_name", columnNames = { "name" } ) }) public class car {    @Id    @GeneratedValue(strategy = SEQUENCE, generator = "car_seq")    private Long id;    @Column(nullable = false)    @NotEmpty(message = "Name must not be null or empty")    private String name; // other stuff

And the service - pretty standard update method - note I want the safety net of @Transactional.

@Transactional    public carCreateDto updatecar(carCreateDto updatecarDto, Long id) {        car car = carRepository.findById(id).orElseThrow(() -> new EntityNotFoundException("car with " + id + " not found"));            carMapper.partialUpdate(updatecarDto, car);            carRepository.save(car);            return carMapper.toDto(car);    }

And then on my controller
@PutMapping(value = "/{id}", consumes = "application/json")    ResponseEntity<CarCreateDto> updateCarDto(@Valid @RequestBody CarCreateDto updateCar, @PathVariable Long id) {            CarCreateDto car = carService.updateCar(updateCar, id);            return new ResponseEntity<>(car, HttpStatus.OK);        }

And finally the exception handler. This was the one that took the most experimenting. Note i had to use e.getCause().getCause() twice to drill down into the second level of the exception to confirm its a SQL Constraint Violation.

   @ExceptionHandler(DataIntegrityViolationException.class)    public ResponseEntity<?> dataIntegrityViolantionException(final DataIntegrityViolationException e) {        String mostSpecificCauseMessage = e.getMostSpecificCause().getMessage();        if (e.getCause().getCause() instanceof SQLIntegrityConstraintViolationException) {            return new ResponseEntity<>(mostSpecificCauseMessage, HttpStatus.CONFLICT);        }        return new ResponseEntity<>("Unknown Data Integrity Violation Exception with message : " +mostSpecificCauseMessage, HttpStatus.CONFLICT);    }

Gives a error like : `Duplicate entry 'Barry' for key 'car.uc_name'`

So questions:
1. Does this approach make sense and could it be improved - particularly the exception handling?
2. Are there other "common" SQL exceptions i should be checking for, i.e. instanceOf SQL.....

Thanks in advance.

Al