T variable

Kopyala

                        public class GenericRepository<T> where T : class
{
    private readonly DbContext _context;   // Connect database

    public GenericRepository(DbContext context)   
    {
        _context = context;
    }

    public IQueryable<T> GetAll()   // All records of type T are returned as a query
    {
        return _context.Set<T>();  // Accessing table T in DbContext
    }
}
                    

Product table

Kopyala

                        // Product table
var productRepo = new GenericRepository<Product>(dbContext);
var products = productRepo.GetAll()
                          .Where(p => p.Name.Contains("abc"))
                          .ToList();

                    

Customer table

Kopyala

                        // Customer Table
var customerRepo = new GenericRepository<Customer>(dbContext);
var customers = customerRepo.GetAll()
                             .Where(c => c.City == "İstanbul")
                             .ToList();
                    

Result

The same GetAll() method works for both Product and Customer because the type T is determined when that repository instance is created.