feat: add a type of occupation create

Application/Cqrs/TypeOfOccupation/Commands/CreateTypeOfOccupation/TypeOfOccupationCommand.cs

@@ -0,0 +1,9 @@
+using MediatR;
+
+namespace Mirea.Api.DataAccess.Application.Cqrs.TypeOfOccupation.Commands.CreateTypeOfOccupation;
+
+public class TypeOfOccupationCommand : IRequest<int>
+{
+    public required string ShortName { get; set; }
+    public string? FullName { get; set; }
+}

Application/Cqrs/TypeOfOccupation/Commands/CreateTypeOfOccupation/TypeOfOccupationCommandHandler.cs

@@ -0,0 +1,30 @@
+using MediatR;
+using Microsoft.EntityFrameworkCore;
+using Mirea.Api.DataAccess.Application.Common.Exceptions;
+using Mirea.Api.DataAccess.Application.Interfaces.DbContexts.Schedule;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Mirea.Api.DataAccess.Application.Cqrs.TypeOfOccupation.Commands.CreateTypeOfOccupation;
+
+public class TypeOfOccupationCommandHandler(ITypeOfOccupationDbContext dbContext) : IRequestHandler<TypeOfOccupationCommand, int>
+{
+    public async Task<int> Handle(TypeOfOccupationCommand request, CancellationToken cancellationToken)
+    {
+        var entity = await dbContext.TypeOfOccupations.FirstOrDefaultAsync(t => t.ShortName == request.ShortName, cancellationToken: cancellationToken);
+
+        if (entity != null)
+            throw new RecordExistException(typeof(Domain.Schedule.TypeOfOccupation), nameof(Domain.Schedule.TypeOfOccupation.ShortName), entity.Id);
+
+        var typeOfOccupation = new Domain.Schedule.TypeOfOccupation
+        {
+            ShortName = request.ShortName,
+            FullName = request.FullName
+        };
+
+        var result = await dbContext.TypeOfOccupations.AddAsync(typeOfOccupation, cancellationToken);
+        await dbContext.SaveChangesAsync(cancellationToken);
+
+        return result.Entity.Id;
+    }
+}