What's the best practice for working with nullable SQL data in C#?

Question

I tend to do this, for example a method that accepts an integer:

DoSomethingWithThisInt((int)dbObj.nullableInteger);

However I will also usually ensure that this code will never happen unless it has a value, sometimes this means I have to check for null first which takes more lines of code.

Is there a better way or am I doing this right by simply casting?

Answer 1

If you've already checked for null prior to the line of code in question, you can simply use

dbObj.nullableInteger.Value

As opposed to a cast.

If, for example, default values would also be sufficient (such as 0 for integers, false for booleans, etc.), then you can omit the null check and simply utilize

doObj.nullableInteger.GetValueOrDefault()

Answer 2

Basically there are two choices for syntax. Either use the properties of the Nullable<T> type, like so:

if (dbObj.nullableInteger.HasValue)
{
    DoSomethingWithThisInt(dbObj.nullableInteger.Value);
}

or use the syntactic sugar provided by the C# language, which translates to the same thing:

if (dbObj.nullableInteger != null)
{
    DoSomethingWithThisInt((int)dbObj.nullableInteger);
}

Which one you use is just a matter of preference; personally I prefer the latter.