How to filter IEnumerable based on an entity input parameter

Question

I\'m using now Entity framework- but it\'s a problem \"shared\" between all ORM\'s and even IEnumerable.

Let\'s say I have a method in MVC looks like this:

Answer 1

Your hard coded method is the best method generally.

However you can try to make your life a little easier by writing an appropriate extension method to help keep the code clean.

Try this for example:

public static class QueryableEx
{
    public static IQueryable Where(
        this IQueryable @this,
        bool condition,
        Expression> @where)
    {
        return condition ? @this.Where(@where) : @this;
    }
}

Now you could write this code:

[HttpPost]
public ActionResult Foo(FooModel model)
{
    using (var context = new Context())
    {
        var data = context.Foo
            .Where(model.Date != null, x => x.Date == model.Date)
            .Where(model.Name != null, x => x.Name == model.Name)
            .Where(model.ItemCode != null, x => x.ItemCode == model.ItemCode)
            .ToList();
        return View(data);
    }
}

(Please don't forget to dispose of your context or use using to do it for you.)