C # – Pass the LINQ expression as a string?

using (var ctx = new MyEntities())
 {
 var devices = ctx.Devices
 .Where(x=> x.Device == "TEST")
 .ToList();
 return devices;
 }

String expression = "x=> x.Device == \"TEST\"" ;

 using (var ctx = new MyEntities())
 {
 var devices = ctx.Devices
 .Where(expression)
 .ToList();
 return devices;
 }

The following code works fine

 using (var ctx = new MyEntities())
 {
 var devices = ctx.Devices
 .Where(x=> x.Device == "TEST")
 .ToList ();
 return devices;
 }

What I want to do is to pass in the expression in the “Where” clause. I see that it may require a string, But the following throws an error:

String expression = "x=> x.Device == \"TEST\"" ;

 using (var ctx = new MyEntities())
 {
 var devices = ctx.Devices
 .Where(expression)
 .ToList();
 return devices;
 }

The error message at runtime is “The query syntax is invalid. Recent’>’, line 6, column 4.”; What is the best way to pass the expression originally derived from the string?

You have to build the expression manually.

IIRC, there is a DynamicExpressions library in the LINQ101 sample, which can do this for you Task.