(B) Add get by id query for employee

Clinics.Backend/Application/Employees/Queries/GetById/GetEmployeeByIdHandler.cs

+using Application.Abstractions.CQRS.Queries;
+using Application.Employees.Queries.GetBySerialNumber;
+using Domain.Repositories;
+using Domain.Shared;
+
+namespace Application.Employees.Queries.GetById;
+
+public class GetEmployeeByIdHandler : IQueryHandler<GetEmployeeByIdQuery, GetEmployeeByIdResponse>
+{
+    #region CTOR DI
+    private readonly IEmployeesRepository _employeesRepository;
+
+    public GetEmployeeByIdHandler(IEmployeesRepository employeesRepository)
+    {
+        _employeesRepository = employeesRepository;
+    }
+
+    #endregion
+
+    public async Task<Result<GetEmployeeByIdResponse>> Handle(GetEmployeeByIdQuery request, CancellationToken cancellationToken)
+    {
+        #region 1. Fetch from persistence
+        var employeeFromPersistenceResult = await _employeesRepository.GetByIdAsync(request.Id);
+        if (employeeFromPersistenceResult.IsFailure)
+            return Result.Failure<GetEmployeeByIdResponse>(employeeFromPersistenceResult.Error);
+        var employee = employeeFromPersistenceResult.Value;
+        #endregion
+
+        return Result.Success<GetEmployeeByIdResponse>
+            (GetEmployeeByIdResponse.GetResponse(employee));
+    }
+}

Clinics.Backend/Application/Employees/Queries/GetById/GetEmployeeByIdQuery.cs

+using Application.Abstractions.CQRS.Queries;
+
+namespace Application.Employees.Queries.GetById;
+
+public class GetEmployeeByIdQuery : IQuery<GetEmployeeByIdResponse>
+{
+    public int Id { get; set; }
+}

Clinics.Backend/Application/Employees/Queries/GetById/GetEmployeeByIdResponse.cs

+using Application.Employees.Queries.GetBySerialNumber;
+using Domain.Entities.People.Employees;
+
+namespace Application.Employees.Queries.GetById;
+
+public class GetEmployeeByIdResponse
+{
+    public int Id { get; set; }
+    public string FirstName { get; set; } = null!;
+    public string MiddleName { get; set; } = null!;
+    public string LastName { get; set; } = null!;
+    public string Gender { get; set; } = null!;
+    public DateOnly DateOfBirth { get; set; }
+    public string SerialNumber { get; set; } = null!;
+    public string CenterStatus { get; set; } = null!;
+
+    public static GetEmployeeByIdResponse GetResponse(Employee employee)
+    {
+        return new GetEmployeeByIdResponse
+        {
+            Id = employee.Id,
+            FirstName = employee.Patient.PersonalInfo.FirstName,
+            MiddleName = employee.Patient.PersonalInfo.MiddleName,
+            LastName = employee.Patient.PersonalInfo.LastName,
+            Gender = employee.Patient.Gender.Name,
+            DateOfBirth = employee.Patient.DateOfBirth,
+            SerialNumber = employee.SerialNumber,
+            CenterStatus = employee.CenterStatus
+
+        };
+    }
+}

Clinics.Backend/Persistence/Repositories/Employees/EmployeesRepository.cs

@@ -21,6 +21,23 @@ public class EmployeesRepository : Repositroy<Employee>, IEmployeesRepository
     }
     #endregion
 
+    #region Read methods
+    public override async Task<Result<Employee>> GetByIdAsync(int id)
+    {
+        try
+        {
+            var query = _context.Set<Employee>()
+                .Where(employee => employee.Id == id);
+            var result = await query.FirstAsync();
+            return await GetEmployeeBySerialNumberAsync(result.SerialNumber);
+        }
+        catch (Exception)
+        {
+            return Result.Failure<Employee>(PersistenceErrors.NotFound);
+        }
+    }
+    #endregion
+
     #region Get by serial Number
     public async Task<Result<Employee>> GetEmployeeBySerialNumberAsync(string serialNumber)
     {
@@ -36,5 +53,6 @@ public class EmployeesRepository : Repositroy<Employee>, IEmployeesRepository
             return Result.Failure<Employee>(DomainErrors.SerialNumberNotFound);
         return Result.Success(result.First());
     }
+
     #endregion
 }

Clinics.Backend/Presentation/Controllers/EmployeesController.cs

 using Application.Employees.Commands.AttachFamilyMemberToEmployee;
 using Application.Employees.Commands.CreateEmployee;
+using Application.Employees.Queries.GetById;
 using Application.Employees.Queries.GetBySerialNumber;
 using Domain.Entities.Identity.UserRoles;
 using MediatR;
@@ -39,6 +40,18 @@ public class EmployeesController : ApiController
         return Ok(result.Value);
     }
 
+    //[Authorize(Roles = Roles.ReceptionistName)]
+    [HttpGet("{id:int}")] // It's a get, but serial number shouldn't be sent via routing, so we'll use post
+    public async Task<IActionResult> GetById([FromRoute] int id)
+    {
+        var query = new GetEmployeeByIdQuery { Id = id };
+        var result = await _sender.Send(query);
+        if (result.IsFailure)
+            return HandleFailure(result);
+        return Ok(result.Value);
+    }
+
+
     //[Authorize(Roles = Roles.ReceptionistName)]
     [HttpPut("FamilyMembers")]
     public async Task<IActionResult> AttachFamilyMember([FromBody] AttachFamilyMemberToEmployeeCommand command)