2

I would like to create a IQueryable Where method as shown below:

public static IQueryable Where(this IQueryable source, string predicate, params object[] values)
{}

So instead of Where(u => u.Points >= 20) I could pass a string predicate like Where("Points >= param0", 20)

What would be involved in accomplishing this task?

  • Why do you want to do that? – CodingYoshi Feb 19 '17 at 1:37
  • So a user can input a query or function ((10 * Cos(param0)) + parm1) >= 3, with params (4, 7). I would like a user in a WinForm to enter a predicate with params and this would be executed with a result. – DaveSmith Feb 19 '17 at 1:44
  • See this SO question. – CodingYoshi Feb 19 '17 at 2:02
2

The code to accomplish what you are asking is large, it is easier to use NuGet package NequeoLinq. Sample code, first add the extension

using Nequeo.Extension;
using Nequeo.Linq.Extension;

On any collection type:

Where("ProOne >= @0 && ProTwo <= @1", 30, 70);

Pass the predicate as a string containing the property names of the collection type and the collection of parameters contained in the predicate (@0, @1 refer to 30 and 70).

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