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ryankirkman / DapperLite

A Dapper compatible library that works on .NET Compact Framework
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ArgumentNull Exception in SqlMapper.cs #3

Closed RefractedPaladin closed 10 years ago

RefractedPaladin commented 10 years ago

Specifically line 100 in SqlMapper.cs is throwing that.

pi.SetValue(objectClass, value, null);

Values for those parameters are Models.Employee & 1

It should be trying to assign the Id as pi is an Int32 from the Column Id

ryankirkman commented 10 years ago

Have you stepped through the code and inspected the values right before the exception? I'd be interested to see which argument it thinks is null. I have a feeling it might be the Models.Employee instance. Let me know what you find.

RefractedPaladin commented 10 years ago

I did and it didn't seem so. I'll double check though. The Values I mentioned above are right at that point where it throws Exception.

RefractedPaladin commented 10 years ago

The objectClass parameter of the PopulateClass() method that this is occuring in is set to Models.Employee...

I'm looking though, maybe I'm not instantiating it correctly...

RefractedPaladin commented 10 years ago

Nope, Employee instance is definetly there. I posted this same question on SO, here --> http://stackoverflow.com/questions/21003185/argumentexception-on-propertyinfo-setvalue-in-net-compact

Crowd sourcing, as it were, as I'm sure you are busy and who knows if I'm doing something silly again.

RefractedPaladin commented 10 years ago

Not sure if this matters or not but when I step through the code and inspect the values I notice that, in SqlMapper.cs on line 99, the actualType == Int32 and the columnType==Int64 while the value it's evaluating is 1. Not sure that makes any difference since you have a actualType.Equals(typeof(int)) but figured I'd mention it.

ryankirkman commented 10 years ago

That's actually pretty interesting, but will work fine. It should be caught by the last condition in the first if statement branch: https://github.com/ryankirkman/DapperLite/blob/master/DapperLite.NETCF35/SqlMapper.cs#L86

e.g. actualType == typeof(int)

int is a synonym for Int32 in C#, so it will directly assign 1 to the Int64 column. I think this is fine, as any Int32 value will easily fit in an Int64. If it was going the other way, e.g. assigning an Int64 to an Int32 we'd have problems.

RefractedPaladin commented 10 years ago

That's what I figured as well but thought I'd check. Unfortunately I am running out of things to even try at this point. Bummer as I was really looking forward to using this library as well as it's big brother.

Thanks for the help so far.

ryankirkman commented 10 years ago

No worries mate. I'll tell you what - I'll load up your class when I get a chance and try to reproduce the problems you're experiencing.

ryankirkman commented 10 years ago

The other thing your could try is changing your model such that Id is an Int64 rather than int. Let me know how that goes

RefractedPaladin commented 10 years ago

Hey Thanks! Whatever you can spare is very appreciated!

So, changing it to Int64 in my model worked.... :-)

ryankirkman commented 10 years ago

Huh, that's interesting. Turns out you can't directly assign an Int32 to an Int64 via PropertyInfo.SetValue. Now we know :)

Mind if I answer the question on StackOverflow?

RefractedPaladin commented 10 years ago

No, go ahead. I'll vote it up and check it the answer. Will you make any chanegs to SqlMapper.cs to account for this? I wonder why it thinks it's Int64, must be a SQLite thing huh?

ryankirkman commented 10 years ago

Yeah, good question. I will make a change, but I have to think what the best way to go about this is. I think it might be dropping those last two conditions on the first part of the if statement. That will fix a few bugs actually, and I'll do that now.

ryankirkman commented 10 years ago

Fixed: 43f5588ec15c54c8dea40fec15f3a0b5a9a73f07!

Try pulling the latest changes and let me know if you have any more problems :)

ryankirkman commented 10 years ago

@RefractedPaladin Actually, just landed a change to the if statement that should keep it super fast for simple value type Type comparisons: d76db77f78a8023960097f8da09a722892950dee

ryankirkman commented 10 years ago

Based on the info in this blog post: http://blogs.msdn.com/b/csharpfaq/archive/2004/03/29/when-should-i-use-and-when-should-i-use-equals.aspx

RefractedPaladin commented 10 years ago

Nice! That makes sense. I'm up and running on it now so I'll let you know how it goes.

Thanks for the help!

On Fri, Jan 17, 2014 at 2:22 PM, Ryan Kirkman notifications@github.comwrote:

Based on the info in this blog post: http://blogs.msdn.com/b/csharpfaq/archive/2004/03/29/when-should-i-use-and-when-should-i-use-equals.aspx

— Reply to this email directly or view it on GitHubhttps://github.com/ryankirkman/DapperLite/issues/3#issuecomment-32643001 .