CODEWITHSUNDEEP
.netlinqlinq-to-sqlcompiled-query
Hosam Aly
Hosam Aly

Reputation: 42443

How do I refactor compiled LINQ queries?

Is it possible to refactor compiled LINQ to SQL queries? Suppose that I have a query with some logic, and I'd like to build onto it. Is it possible to reuse that query?

For example, suppose I have a basic query to get active items:

Func<DataContext, IQueryable<Item>> GetActiveItems =
    CompiledQuery.Compile((DataContext context) =>
        context.Items.Where(item => item.IsActive));

I'd like to build onto the above expression to make another query. The documentation of CompiledQuery indicates that I cannot apply another operator on the result of the compiled delegate. So what is the recommended way of refactoring such expressions?

I think I should be using an Expression, but how should it be used? Or is there a better way?

Upvotes: 1

Views: 169

Answers (1)

Tim Croydon
Tim Croydon

Reputation: 1896

You can use something like PredicateBuilder to help with this:

The Albahari one is simple and works quite well although it's easy to extend or develop you own: http://www.albahari.com/nutshell/predicatebuilder.aspx

Obviously if your query relies on a local method that can't be translated to a SQL expression you'll have to rethink how you do it.

Upvotes: 1

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