private static void ConflictingChangesPessimistic()
{
var contextFirst = new SoftUniEntities();
var townFirst = contextFirst.Towns
.OrderByDescending(t => t.TownID)
.First();
townFirst.Name = "changed by the first user";
var contextSecond = new SoftUniEntities();
var townSecond = contextSecond.Towns
.OrderByDescending(t => t.TownID)
.First();
townSecond.Name = "changed by the second user";
contextFirst.SaveChanges();
try
{
contextSecond.SaveChanges();
}
catch (DbUpdateConcurrencyException ex)
{
Console.WriteLine("Conflicting update occurred.");
Console.WriteLine(ex.Message);
}
}
private static void AddTown()
{
using (var context = new SoftUniEntities())
{
context.Towns.Add(new Town()
{
Name = "New Town"
});
context.SaveChanges();
}
}
private static void AddProject()
{
using (var context = new SoftUniEntities())
{
var project = new Project()
{
Name = "New project",
Description = "some description",
StartDate = new DateTime(2015, 1, 1),
EndDate = new DateTime(2015, 12, 31)
};
context.Projects.Add(project);
context.SaveChanges();
}
}
private static void ConflictingChangesOptimistic()
{
//first user changes the project name
var contextFirst = new SoftUniEntities();
var projectFirstUser = contextFirst.Projects
.OrderByDescending(p => p.ProjectID)
.First();
projectFirstUser.Name = "changed by the first user";
//second user changes the same project name
var contextSecond = new SoftUniEntities();
var projectSecondUser = contextSecond.Projects
.OrderByDescending(p => p.ProjectID)
.First();
projectSecondUser.Name = "changed by the second user";
//the last change wins
contextFirst.SaveChanges();
contextSecond.SaveChanges();
}