我可以在Linq表达式中将String参数用作实体属性和对象属性吗？

Question

This is my first question, I'm doing the best I can to be understand.

I want to insert in table that has many unique properties.

I want to use string instead of property in a Linq expression.

I want to make something like this:

public List<string> AddEmploye(Employe pEmploye)
{
   List<string> NonUnique = new List<string>();
   List<string> Prop = new List<string>
      {
         "ID",
         "NAS",
         "CODE",
      };

   foreach (var prop in Props)
   {
      var result = (from t in _context.TEMP02A
                  where t.prop == pEmploye.prop
                  select t.name).ToList();

      if (result.Count() > 0)
        NonUnique.Add(prop);
   }
   return NonUnique;
}

I tried many solutions proposed on StackOverflow but neither worked for my case.

I tried these solutions: 0 , 1 , 2 , 3 , and many others, but none of those solutions works for my case.

I expect the result.count to be 0 or higher, but when I tried this solution , I got this error :

LINQ to Entities does not recognize propertyInfo.GetValue.

Any suggestions?

Answer 1

You could try dynamic linq . It's a bit old, but it allows you to do things like:

Where($"property_name_as_string = @0", some_value)

In your case it would be something like:

.Where(prop + " = @0",employee_prop_value_by_reflection_here)
.Select("Name");

As from your example:

var val = GetPropValue(pEmploye, prop);
_context.TEMP02A.Where(prop + " = @0",val);