Cannot implicitly convert type 'int?' to 'int'.

You'll need to post more code to get a definitive answer, but somewhere one of your variables is nullable, and to assign it to a non-nullable type you need to do .Value.

For example, if your object d's property imie is Nullable<int>, and that is what is causing your problem, you could do this:

imie = d.imie.Value

You will also need to watch for cases where d.imie is null. For example:

imie = d.imie.HasValue ? d.imie.Value : 0

Or, if you like the ?? operator (which evaluates to the first non-null value):

imie = d.imie ?? 0

(I am just using d.imie as an example -- there is not enough code posted to pintpoint the exact problem.)

int? is the Nullable<int>. Since database columns may be null, the mapped properties are Nullable.

Consider this code which assigns int? values to int variables.

int? w = 2;
int? x = null;
int y = w ?? 3;
int z = x ?? 4;

In your uzytkownikModel class, the properties that are nullable should be declared as "int?" or "decimal?" instead of "int" and "decimal".