Calculated column in EF Code First

Question

I need to have one column in my database calculated by database as (sum of rows) - (sum of rowsb). I\'m using code-first model to create my database.

Here is what I

Answer 1

One way is doing it with LINQ:

var userID = 1; // your ID
var income = dataContext.Income.First(i => i.UserID == userID);
var outcome = dataContext.Outcome.First(o => o.UserID == userID);
var summ = income.inSumm - outcome.outSumm;

You may do it within your POCO object public class FirstTable, but I would not suggest to, because I think it's not good design.

Another way would be using a SQL view. You can read a view like a table with Entity Framework. And within the view code, you may do calculations or whatever you want. Just create a view like

-- not tested
SELECT FirstTable.UserID, Income.inCome - Outcome.outCome
  FROM FirstTable INNER JOIN Income
           ON FirstTable.UserID = Income.UserID
       INNER JOIN Outcome
           ON FirstTable.UserID = Outcome.UserID