This simple PredicateBuilder example does not work - clueless?

ARMPLINKER

I have attempted to follow the example for PredicateBuilder given in the help and I am getting this error:

variable 'f' of type 'LINQPad.User.Paramtrs' referenced from scope '', but it is not defined
for this:

var predicate = PredicateBuilder.False<Paramtrs>();
bool normalize = true;
string[] criteriaStr = { "district" };
foreach (var str in criteriaStr)
{
var temp = normalize?str.ToLower().Trim() : str;
predicate = predicate.Or< Paramtrs>(f => (normalize?f.FieldName.ToLower().Trim() : f.FieldName) == temp);  
}
Paramtrs**.Where (predicate).Dump();

The only difference I have made here is that I have forced the values to lowercase and trim because the database entries themselves may have inconsistent capitalization. Doubtless there is a smarter way to do that. However, with or without that normalization, the example does not work.

Paramtrs is a table in the database I am using. I know it exists and I know it has data.

This following bit as a C# expression does work from LinqPad.

from p in Paramtrs
where p.TableName=="bridge" && p.FieldName=="district" && p.Isactive==1
orderby p.OrderNum
select p

Ultimately I might want to apply a couple criteria. I am frankly lost here. Any guidance would be appreciated.

ARMPLINKER

That is, I am clueless. However, I am a clueless licensee

Thank you!

JoeAlbahari

Depending on what ORM you are using, you may need to call AsExpandable before executing the query:

Paramtrs.AsExpandable().Where (predicate).Dump();

AsExpandable is part of LINQKit:
http://www.albahari.com/nutshell/linqkit.aspx

The easiest way to get LINQKit is via the LinqKit.Core NuGet package.