Check if decimal value is null

A decimal will always have some default value. If you need to have a nullable type decimal, you can use decimal?. Then you can do myDecimal.HasValue

decimal is a value type in .NET. And value types can't be null. But if you use nullable type for your decimal, then you can check your decimal is null or not. Like myDecimal?

Nullable types are instances of the System.Nullable struct. A nullable type can represent the normal range of values for its underlying value type, plus an additional null value.

if (myDecimal.HasValue)

But I think in your database, if this column contains nullable values, then it shouldn't be type of decimal.

Assuming you are reading from a data row, what you want is:

if ( !rdrSelect.IsNull(23) ) 
{ 
   //handle parsing
}

you can use this code

if (DecimalVariable.Equals(null))  
{
   //something statements
}