I prefer the repository pattern, i.e. a stateless object for roughly each entity type, containg methods such as

void CustomerRepository.createCustomer(Customer c)

List<Customer> CustomerRepository.getCustomersByCountry(String country)

• Easy to add additional handling such as serialization, error handling, logging, validation
• Easy to find the correct function
• Less likely to have duplicate code
• Easy to migrate to a different database technology
• Easy to mock for testing
• Easy to instrument for performance monitoring

I prefer the Table Data Gateway pattern, i.e. a stateless object for roughly each entity type, containg methods such as

void CustomerRepository.createCustomer(Customer c)

List<Customer> CustomerRepository.getCustomersByCountry(String country)

• Easy to add additional handling such as serialization, error handling, logging, validation, caching.
• Easy to find the correct function
• Less likely to have duplicate code
• Easy to migrate to a different database technology
• Easy to mock for testing
• Easy to instrument for performance monitoring