Blazor Server - System.InvalidCastException: Unable to cast object of type 'System.Double' to type 'System.Single'.

Question

Hi,

In my Blazor server application, I am trying to get the records from RazerReconciliation table as follows. I couldn't figure out why I am getting this error.

public async Task<List<RazerReconciliations>> GetOldReconsAsync()
{
      var result = await _oyunPalasContext.RazerReconciliation.ToListAsync();
      return result;
}

Here is the model;

public class RazerReconciliations
    {
        public string? PID { get; set; }
        public string? ProductName { get; set; }
        public float ProductAmount { get; set; }
        public Guid ReferenceNo { get; set; }
        public int Quantity { get; set; }
        public DateTime TransactionDateTime { get; set; }
        public string? Explanation { get; set; }

    }

Here is the table:

CREATE TABLE [dbo].[RazerReconciliation](
	[PID] [nvarchar](50) NULL,
	[ProductName] [nvarchar](200) NULL,
	[ProductAmount] [float] NULL,
	[ReferenceNo] [uniqueidentifier] NOT NULL,
	[Quantity] [int] NOT NULL,
	[TransactionDateTime] [datetime] NULL,
	[Explanation] [varchar](200) NULL
) ON [PRIMARY]

Here is the Context:

public virtual DbSet<RazerReconciliations> RazerReconciliation { get; set; } = null!;
modelBuilder.Entity<RazerReconciliations>().HasNoKey();

Answer 1

According to https://learn.microsoft.com/en-us/dotnet/framework/data/adonet/sql-server-data-type-mappings, try using float in SQL and double in C#.

By the way, maybe decimal datatypes are more suitable.