This seemed like a great solution at the time, but is quite a lot of code, as you are writing a method for every…single…datatype that your application interacts with. Being in a Small Business you didn’t really get the ability to refactor code that often, so once it was written you stuck by it.
Moving along in my career I stepped into Environment that already had full DALs in place so I would mimic what the previous developer did in order to keep the code base easily maintainable, as there is never a lack of fun trying to understand more than one persons point of view across a piece of code.
Tonight I was scanning through twitter and noticed Ben Alabaster [@BenAlabaster] asking a quite a unique question on twitter. So I piped in with my two cents, and then the conversation sparked beyond twitter to msn, then eventually to Skype. Here is the unique Single Helper Method we came up with:
For .NET 2.0, a static method:
public static T ConvertDBNullToSafeOrDefaultTypeValue<T>(object field)
{
if (field != DBNull.Value)
return (T)Convert.ChangeType(field, typeof(T));
return default(T);
}
For .NET 3.5, an Extension method:
public static T ConvertDBNullToSafeOrDefaultTypeValue<T>(this object field)
{
if (field != DBNull.Value)
return (T)Convert.ChangeType(field, typeof(T));
return default(T);
}
This solution provides a source code friendlier way of returning values from a database and validating the data against your business rules [you can replace default(T) is a Generic way of handling your applications default values].
Happy Coding!