LINQ to Entities - How to retrieve a data and use it as a variable in the whole project

Question

Hi I have 1 WinForm and 2 tables: - Form1 contains TextBox1 - Employee contains ID LastName FirstName BirthDate. - Tasks contains ID TaskName I need to input LastName and FirtName in TextBox1 to retrieve the related TaskName if exists then make the retrieved data usable from any location in the project I need to know where to put the TaskName variable? and how can I modify the next code to reach that purpose? using (LINQtoEntitiesEntities MyEntities = new LINQtoEntitiesEntities()) { ObjectQuery Employee = MyEntities.Employee; var query = (from p in Employee where p.FirstName == TextBox1.Text.Trim() select p.LasttName p.FirstName); } Thanks

Vulpes · Answer

If LastName and FirstName are being input (in that order) to TextBox1 then assuming they are separated by a space or spaces you can split them up as follows: string[] items = TextBox1.Text.Trim().Split(new char[]{' '} StringSplitOptions.RemoveEmptyEntries); string lastName = items[0]; string firstName = items[1]; The second argument to the Split method deals with the possibility that there might be multiple spaces separating the last and first names. If the ID column is used to link the Employee and Tasks tables you should then be able to retrieve the related TaskName and place it in a global variable as follows: // create a class to contain global variables if you don't already have one static class Global { public static string Task {get; set;} } // within some method in some other class // insert above code to get last and first names using (LINQtoEntitiesEntities MyEntities = new LINQtoEntitiesEntities()) { ObjectQuery Employee = MyEntities.Employee; ObjectQuery Tasks = MyEntities.Tasks; Global.Task = (from e in Employee where e.LastName == lastName && e.FirstName == firstName join t in Tasks on e.ID equals t.ID select t.TaskName).FirstOrDefault(); } // retrieve global variable from elsewhere: if (Global.Task != null) { // do something with Global.Task }

Vulpes · Answer

Yes you could instead make it a public (or internal) static variable of either the Program class or the Form1 class. I usually prefer to put my global variables in a separate Global class so I can easily find them but it's just a matter of taste.

Samio · Answer

Hi Vulpes I tested your solution it's good. Do you think it should be better if I place the Global Variable in Program or maybe in Form1 before: public partial class Form1 :Form