Questions about repository pattern with Entity Framework Core - entity-framework-core

Question

I have created an API that is using EF Core with a repository pattern and I have few questions:
Post method receives an email address and verify whether user exists on not.
If an email address does not exist in the User table, get the guest access details from the AccessManagement table and save in Entitlement table and return the details
If the entry exists, get the user access details and return them
IGeneralRepository:
public interface IGenrealRepository<TEntity> where TEntity : class , new()
{
IQueryable<TEntity> GetAll();
Task<TEntity> AddAsync(TEntity entity);
Task<TEntity[]> AddRangeAsync(TEntity[] entity);
TEntity Update(TEntity entity);
Task<int> CompleteAsync();
}
General repository:
public class GeneralRepository<TEntity> : IGenrealRepository<TEntity> where TEntity : class, new()
{
private MyDbContext _myDbContext;
public GeneralRepository(MyDbContext myDbContext)
{
_myDbContext = myDbContext;
}
public async Task<TEntity> AddAsync(TEntity entity)
{
if (entity == null)
{
throw new ArgumentNullException($"{nameof(AddAsync)} entity must not be null");
}
try
{
await _myDbContext.AddAsync(entity);
return entity;
}
catch (Exception ex)
{
throw new Exception($"{nameof(entity)} could not be saved: {ex.Message}");
}
}
public async Task<TEntity[]> AddRangeAsync(TEntity[] entity)
{
if (entity == null)
{
throw new ArgumentNullException($"{nameof(AddRangeAsync)} entity must not be null");
}
try
{
await _myDbContext.AddRangeAsync(entity);
return entity;
}
catch (Exception ex)
{
throw new Exception($"{nameof(entity)} could not be saved: {ex.Message}");
}
}
public async Task<int> CompleteAsync()
{
return await _myDbContext.SaveChangesAsync();
}
public IQueryable<TEntity> GetAll()
{
try
{
return _myDbContext.Set<TEntity>();
}
catch (Exception ex)
{
throw new Exception($"Couldn't retrieve entities: {ex.Message}");
}
}
public TEntity Update(TEntity entity)
{
try
{
_myDbContext.Update<TEntity>(entity);
return entity;
}
catch (Exception ex)
{
throw new Exception($"{nameof(entity)} could not be updated: {ex.Message}");
}
}
}
IUserService:
public interface IUserService
{
Task<User> CreateUser(string emailId);
Task<int> Complete();
}
UserService implementation:
public class UserService : IUserService
{
private readonly IUserRepository _userRepository;
private readonly IAccessManagementRepository _accessManagementRepository;
public UserService(IUserRepository userRepository, IAccessManagementRepository accessManagementRepository)
{
_userRepository = userRepository;
_accessManagementRepository = accessManagementRepository;
}
public async Task<int> Complete()
{
return await _userRepository.CompleteAsync();
}
public async Task<User> CreateUser(string emailId)
{
var user = _userRepository.GetAll()
.Where(x => x.EmailId.ToUpper() == emailId.ToUpper())
.FirstOrDefault();
if (user == null)
{
var entitlements = await _userAccessRepository.GetAll()
.Where( x => x.Default == true)
.Select( x => new UserEntitlement() {
Id = x.Id,
AccessName = x.AccessName
}).ToListAsync();
//saving User and Entitlement
user = new User()
{
EmailId = emailId,
UserEntitlements = entitlements
};
user = await _userRepository.AddAsync(user);
}
else
{
// Getting current User Entitlement
var entitlements = await _userRepository.GetAllUserEntitilements();
var entitlement = entitlements.Find(x => x.UserId == user.UserId);
user.UserEntitlements = entitlements;
}
return user;
}
}
API call:
[HttpPost]
public async Task<IActionResult> CreateUser([FromBody] User user)
{
var result = await _userService.CreateUser(user.EmailId);
await _userService.Complete();
return CreatedAtAction(nameof(GetUser), new { emailId = result.EmailId }, result);
}
Questions:
Is my method UserService.CreateUser() implementation correct? Any better approach?
Is the below code is the best approach to filter?
var user = _userRepository.GetAll()
.Where(x => x.EmailId.ToUpper() == emailId.ToUpper())
.FirstOrDefault();
How to get data from User and Entitlement table at one stretch? Something like below Include but can not use include because of an error
var user = _userRepository.GetAll()
.Where(x => x.EmailId.ToUpper() == emailId.ToUpper())
.Include<UserEntitlement>()
.FirstOrDefault();
How to do insert to one table and update to another table in a single transaction?

Answer 1

Leo,
I prefer doing the validation of the email outside the CreateUser function
This comes with another function where you could add to IUserService where you can get the user by email GetUserByEmail.
Doing that you can possibly return a proper error or validation message before invoking the CreateUser at the API Call
For example
[HttpPost]
public async Task<IActionResult> CreateUser([FromBody] User user)
{
var user = await _userService.GetUserByEmail(user.EmailId);
// or var userRegistered = await _userService.UserExistsByEmail(user.EmailId) returning a bool
// user registered?
if (user)
{
// The user already exists, return an error or
// You could update the UserEntitlements here or you could
// make an HttpPut where the user is updated do nothing here
}
....
}
An example
var user = _userRepository.GetAll()
.Include(x => x.UserEntitlements)
.Where(x => x.EmailId.ToUpper() == emailId.ToUpper())
.FirstOrDefault();
You can do it using UnitOfWork
Repository Pattern and Unit of Work