Operator Comparisons

Sometimes you may experience problems with database queries. All providers can not convert Linq to database query. Or just you may prefer use different operators with given parameter. So let's start:

  • You have filter object like that:
public class MyFilter : PaginationFilterBase
	public string Title { get; set; }
  • And you want to use directly operator (==, !=, >, <, >=, <=) comparison instead of Equals(), Contains() or something else methods.

  • Just use [OperatorComparison] attribute with OperatorType parameter.

public class MyFilter : PaginationFilterBase
	[OperatorComparison(OperatorType.Equal)] // <-- This generates query with operator
	public string Title { get; set; }        // something like that: x => x.Title == "something"
  • This attribute generates queries with exactly given operator. For example when you use OperatorType.Equal this will generate query is

x => x.Title == "something"

But StringFilterOptions generates query as

x => x.Title.Equals("something", StringComparison.InvariantCultureIgnoreCase).

MongoDb doesn't support last one. So you can use OperatorComparison if you're using mongodb or something else which doesn't support Equals method.

TODO: Refactor this page

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