private void button3_Click(object sender, EventArgs e)
{
using (var db = new Model2())
{
// creates/adds video and playlist items in db with many to many association.
var newVideo = new Video();
var newPlaylist = new playlist();
newVideo.Name = "New Video";
newPlaylist.Name = "New Playlist";
//uses many to many relationships for both video and playlist
newVideo.Playlists = new List <playlist>()
{
newPlaylist
};
newPlaylist.Videos = new List <Video>()
{
newVideo
};
//updates log
addLineToLog("New Video: " + newVideo.Name);
addLineToLog("New Playlist: " + newPlaylist.Name);
addLineToLog("Many2Many association created for " + newVideo.Name + " and " + newPlaylist.Name);
//adds both the video and playlist to the db as well as their many to many association (table: videoplaylists)
db.Videos.Add(newVideo);
db.playlists.Add(newPlaylist);
db.SaveChanges();
}
}
private void button4_Click(object sender, EventArgs e)
{
// many to many relationship. many different videos can be on many different playlists
int tempID;
//grabs the user input for the Video's ID to use in this example. *caution* currently Does not check for bad input
tempID = Convert.ToInt32(textBox2.Text);
//uses the model2 db (manytomany.db)
using (var db = new Model2())
{
//finds the video the ID of the users input tempID
var tempVideo = db.Videos.Where(v => v.ID == tempID).Include(v => v.Playlists).FirstOrDefault();
//lists all of the names of returned video's playlists
addLineToLog("Video: " + tempVideo.Name + " can be found on the following playlists:");
foreach (var playlist in tempVideo.Playlists)
{
//MessageBox.Show(playlist.Name);
addLineToLog(playlist.Name);
}
//removes any playlist's association with the returned video (table: videoplaylists)
tempVideo.Playlists.Clear();
db.SaveChanges();
}
}