public static void clearDatabase(MusicManagerContext context)
{
var artistQuery = from a in context.Artist select a;
foreach (Artist artist in artistQuery)
{
context.Artist.Remove(artist);
}
var trackQuery = from t in context.MusicTrack select t;
foreach (MusicTrack track in trackQuery)
{
context.MusicTrack.Remove(track);
}
var playlistQuery = from p in context.PlayList select p;
foreach (PlayList playlist in playlistQuery)
{
context.PlayList.Remove(playlist);
}
var mapQuery = from m in context.TrackPlaylistMapping select m;
foreach (TrackPlaylistMapping map in mapQuery)
{
context.TrackPlaylistMapping.Remove(map);
}
context.SaveChanges();
}
public static void Initialize(IServiceProvider serviceProvider)
{
using (var context = new MusicManagerContext(
serviceProvider.GetRequiredService <DbContextOptions <MusicManagerContext> >()))
{
context.Database.Migrate();
string[] artists = new string[] { "Rob Miles", "Fred Bloggs", "The Bloggs Singers", "Immy Brown" };
string[] titles = new string[] { "My Way", "Your Way", "His Way", "Her Way", "Milky Way" };
string[] playlists = new string[] { "Happy", "Sad", "Working" };
// clearDatabase(context); - use this to force a database clear
if (!context.MusicTrack.Any())
{
//need to populate the database with sample data
foreach (string artistName in artists)
{
context.Artist.Add(new Artist {
Name = artistName
});
}
foreach (string playlistName in playlists)
{
context.PlayList.Add(new PlayList {
Name = playlistName
});
}
context.SaveChanges();
Random rand = new Random(1);
// Now spin through the artists adding tracks
// Note that we have to do this so that we can get
// the id value of the artist to add to the MusicTrack
var artistQuery = from a in context.Artist select a;
List <MusicTrack> allTracks = new List <MusicTrack>();
foreach (Artist artist in artistQuery)
{
foreach (string title in titles)
{
context.MusicTrack.Add(new MusicTrack {
ArtistID = artist.ID, Title = title, Length = rand.Next(20, 600)
});
}
}
foreach (Artist artist in artistQuery)
{
foreach (string title in titles)
{
context.MusicTrack.Add(new MusicTrack {
ArtistID = artist.ID, Title = title, Length = rand.Next(20, 600)
});
}
}
context.SaveChanges();
var trackQuery = from t in context.MusicTrack select t;
foreach (MusicTrack t in trackQuery)
{
allTracks.Add(t);
}
// now got a of tracks - can build some playlists
var playlistQuery = from p in context.PlayList where true select p;
foreach (PlayList p in playlistQuery)
{
foreach (MusicTrack m in allTracks)
{
if (rand.Next(10) > 6)
{
continue; // only include some of the records
}
context.TrackPlaylistMapping.Add(new TrackPlaylistMapping
{
PlaylistID = p.ID,
TrackID = m.ID
});
}
}
context.SaveChanges();
}
}
}
