private void button1_Click(object sender, EventArgs e)
{
using (var db = new StackOverflowEntities()) {
blog = db.Blogs.Include("Posts")
.FirstOrDefault();
}
}
private void fetchBlogData_Click(object sender, EventArgs e)
{
using (var db = new StackOverflowEntities()) {
blog = db.Set <Blog>().Include("Posts")
.FirstOrDefault();
}
}
private void button2_Click(object sender, EventArgs e)
{
var post = new Post {
Text = "Hello World"
};
using (var db = new StackOverflowEntities()) {
db.Attach(blog);
blog.Posts.Add(post);
db.SaveChanges();
}
}
private void commitAllPosts_Click(object sender, EventArgs e)
{
using (var db = new StackOverflowEntities()) {
// load existing blog into ChangeTracker
var existingBlog = db.Set <Blog>().First(b => b.BlogId == blog.BlogId);
// add new posts to tracked Blog entity
foreach (var post in blog.Posts)
{
if (post.PostId == 0)
{
// this only works if your Post record has a primary key has Identity Specification set to yes
existingBlog.Posts.Add(post);
}
}
db.SaveChanges();
}
}
private void commitAllPosts_Click(object sender, EventArgs e)
{
using (var db = new StackOverflowEntities()) {
// load existing blog into ChangeTracker (but not efficient)
// var existingBlog = db.Set<Blog>().First(b => b.BlogId == blog.BlogId);
// make shallow copy of existing blog and attach it
Blog existingBlog = new Blog {
BlogId = blog.BlogId,
Name = blog.Name
};
db.Set <Blog>().Attach(existingBlog);
// if the root blog record must be updated
//db.Entry(existingBlog).State == EntityState.Modified;
// add new posts to tracked Blog entity
foreach (var post in blog.Posts)
{
if (post.PostId == 0)
{
existingBlog.Posts.Add(post);
}
}
db.SaveChanges();
}
}
