public void Albums_Delete(int albumid)
{
using (var context = new ChinookContext())
{
var existing = context.Albums.Find(albumid);
if (existing == null)
{
throw new Exception("Album does not exists on file.");
}
//else statement here is optional.
context.Albums.Remove(existing);
context.SaveChanges();
}
}
}//eom
public void DeleteTracks(string username, string playlistname, List <int> trackstodelete)
{
using (var context = new ChinookContext())
{
var exists = (from x in context.Playlists
where x.UserName.Equals(username, StringComparison.OrdinalIgnoreCase) &&
x.Name.Equals(playlistname, StringComparison.OrdinalIgnoreCase)
select x).FirstOrDefault();
if (exists == null)
{
// no: message
throw new Exception("Play list has been removed from the system");
}
else
{
// yes: create a list of playlistTrackIds that are to be kept.
List <PlaylistTrack> trackskept = exists.PlaylistTracks
.Where(tr => !trackstodelete.Any(tod => tr.TrackId == tod))
.Select(tr => tr)
.ToList();
// stage the removal of all the other tracks
PlaylistTrack item = null;
foreach (var dtrackid in trackstodelete)
{
item = exists.PlaylistTracks
.Where(tr => tr.TrackId == dtrackid)
.FirstOrDefault();
if (item != null)
{
exists.PlaylistTracks.Remove(item);
}
}
// renumber the kept tracks
// and stage the update
int number = 1;
trackskept.Sort((x, y) => x.TrackNumber.CompareTo(y.TrackNumber));
foreach (var tKept in trackskept)
{
tKept.TrackNumber = number;
context.Entry(tKept).Property(y => y.TrackNumber).IsModified = true;
number++;
}
// commit
context.SaveChanges();
}
}
}//eom
public int Album_Update(Album album)
{
using (var context = new ChinookContext())
{
if (CheckReleaseYear(album))
{
context.Entry(album).State = System.Data.Entity.EntityState.Modified; //staged
return(context.SaveChanges()); //committed
}
else
{
throw new BusinessRuleException("Validation error: ", reasons);
}
}
}
public int Album_Update(Album item)
{
using (var context = new ChinookContext())
if (CheckReleaseYear(item))
{
context.Entry(item).State =
System.Data.Entity.EntityState.Modified;
return(context.SaveChanges());
}
else
{
throw new BusinessRuleException("Validation Error", reasons);
}
}
public void DeleteTrack(int trackid)
{
using (var context = new ChinookContext())
{
//any business rules
//do the delete
//1. find the existing record on the database
var existing = context.Tracks.Find(trackid);
//2. delete the record from the database
context.Tracks.Remove(existing);
//3. commit delete transaction
context.SaveChanges();
}
}
public void Album_Delete(int albumid)
{
using (var context = new ChinookContext())
{
//any business rules
//do the delete
//find the existing record on the database
var existing = context.Albums.Find(albumid);
//delete the record from the database
context.Albums.Remove(existing);
//commit the transaction
context.SaveChanges();
}
}
}//eom
public void DeleteTracks(string username, string playlistname, List <int> trackstodelete)
{
using (var context = new ChinookContext())
{
//code to go here
var exists = (from x in context.Playlists
where x.UserName.Equals(username) &&
x.Name.Equals(playlistname)
select x).FirstOrDefault();
if (exists == null)
{
throw new Exception("Play list has been removed from the system.");
}
else
{
//find the songs to keep
var tracksKept = exists.PlaylistTracks
.Where(tr => !trackstodelete.Any(tod => tod == tr.TrackId))
.OrderBy(tr => tr.TrackNumber)
.Select(tr => tr);
//remove the tracks to delete
PlaylistTrack item = null;
foreach (var dtrackid in trackstodelete)
{
item = exists.PlaylistTracks
.Where(tr => tr.TrackId == dtrackid)
.Select(tr => tr)
.FirstOrDefault();
if (item != null)
{
exists.PlaylistTracks.Remove(item);
}
}
//resequence kept tracks
int number = 1;
foreach (var tKept in tracksKept)
{
tKept.TrackNumber = number;
context.Entry(tKept).Property("TrackNumber").IsModified = true;
number++;
}
context.SaveChanges();
}
}
}//eom
public int Album_Add(Album album)
{
using (var context = new ChinookContext())
{
if (CheckReleaseYear(album))
{
context.Albums.Add(album); //staged
context.SaveChanges(); //committed
return(album.AlbumId);
}
else
{
throw new BusinessRuleException("Validation error: ", reasons);
}
}
}
public int Album_Delete(int albumID)
{
using (var context = new ChinookContext())
{
var existing = context.Albums.Find(albumID);
if (existing == null)
{
throw new Exception("Album not on file. Delete failed.");
}
else
{
context.Albums.Remove(existing); //staged
return(context.SaveChanges()); //committed
}
}
}
public void Albums_Delete(int _albumID)
{
using (ChinookContext context = new ChinookContext())
{
var existingAlbum = context.Albums.Find(_albumID);
// Ensure provided record exists in the database
if (existingAlbum == null)
{
throw new Exception("Provided album does not exist on file");
}
context.Albums.Remove(existingAlbum);
context.SaveChanges();
}
}
public int Album_Delete(int albumid)
{
using (var context = new ChinookContext())
{
var existing = context.Albums.Find(albumid);
if (existing == null)
{
throw new Exception("Album not on file. Delete unnecessary.");
}
else
{
context.Albums.Remove(existing); //staging
return(context.SaveChanges()); //now committed //returns # records changed
}
}
}
public int Album_Add(Album item)
{
using (var context = new ChinookContext())
{
if (CheckReleaseYear(item))
{
context.Albums.Add(item); //staging
context.SaveChanges(); //committed
return(item.AlbumId); //return new id value
}
else
{
throw new BusinessRuleException("Validation Error", reasons); //Include the library by right clicking on it
}
}
}
public void Update_Track(Track trackinfo)
{
using (var context = new ChinookContext())
{
// any business rules
// Any data refinements
// review of iif
//composer can be a null string, we do not wish to store an empty string
trackinfo.Composer = string.IsNullOrEmpty(trackinfo.Composer) ? null : trackinfo.Composer;
// update the instance of track info to the database
context.Entry(trackinfo).State = System.Data.Entity.EntityState.Modified;
// commit of the update
context.SaveChanges();
}
}
public int Album_Add(Album item)
{
using (var context = new ChinookContext())
{
if (CheckReleaseYear(item))
{
context.Albums.Add(item); //staging
context.SaveChanges(); //comitted
return(item.AlbumId); //returns new ID value
}
else
{
throw new BusinessRuleException("Validation Error", reasons);
}
}
}
public int Album_Add(Album item)
{
using (var context = new ChinookContext())
{
if (CheckReleaseYear(item))
{
context.Albums.Add(item); //staging step, not on db.
context.SaveChanges(); //now committed to the db.
return(item.AlbumId); //returns new id value.
}
else
{
throw new BusinessRuleException("Validation Error", reasons);
}
}
}
public void Add_Track(Track trackinfo)
{
using (var context = new ChinookContext())
{
// any business rules
// Any data refinements
// review of iif
//composer can be a null string, we do not wish to store an empty string
trackinfo.Composer = string.IsNullOrEmpty(trackinfo.Composer) ? null : trackinfo.Composer;
// add the instance of track info to the database
context.Tracks.Add(trackinfo);
// commit of the add
context.SaveChanges();
}
}
public int Album_Delete(int albumid)
{
using (var context = new ChinookContext())
{
var existing = context.Albums.Find(albumid);
if (existing == null)
{
throw new Exception("Album not on file");
}
else
{
context.Albums.Remove(existing);
return(context.SaveChanges());
}
}
}
}//eom
public List <UserPlaylistTrack> DeleteTracks(string username, string playlistname, List <int> trackstodelete)
{
using (var context = new ChinookContext())
{
//find the parent, then the kids
Playlist exists = (from x in context.Playlists
where x.UserName.Equals(username, StringComparison.OrdinalIgnoreCase) && x.Name.Equals(playlistname, StringComparison.OrdinalIgnoreCase)
select x).FirstOrDefault();
//FirstOrDefault() brings in a collection and takes the first one, or default which is null
if (exists == null)
{
throw new Exception("Playlist has been removed");
}
else
{
//the tracks that are to be kept
var tracksKept = exists.PlaylistTracks.Where(tr => !trackstodelete.Any(tdo => tdo == tr.TrackId)).Select(tr => tr);
//remove the tracks in the tracksToDelete list
PlaylistTrack item = null;
foreach (var deleteTrack in trackstodelete)
{
item = exists.PlaylistTracks.Where(dx => dx.TrackId == deleteTrack).FirstOrDefault();
if (item != null)
{
exists.PlaylistTracks.Remove(item);
}
}
//renumber the tracks so that the track number is sequential, as is expected by all other operations
//in our DB there is NO holes in the numeric sequence
int number = 1;
foreach (var trackKept in tracksKept)
{
trackKept.TrackNumber = number;
context.Entry(trackKept).Property(y => y.TrackNumber).IsModified = true;
number++;
}
context.SaveChanges();
return(List_TracksForPlaylist(playlistname, username));
}
}
}//eom
} //eom
public void Remove_TracksFromPlaylist(string playlistName, int trackId)
{
using (var context = new ChinookContext())
{
//need to get the Playlist with the playlistName parameter
Playlist existing = (
from x in context.Playlists
where x.Name.Equals(playlistName)
select x).FirstOrDefault();
//find the track with the traclId
var trackToRemove = context.PlaylistTracks.Find(existing.PlaylistId, trackId);
//remove the track
context.PlaylistTracks.Remove(trackToRemove);
//save the changes to the database
context.SaveChanges();
} //end of using
} //eom
}//eom
public List <UserPlaylistTrack> DeleteTracks(string username, string playlistname, List <int> trackstodelete)
{
using (var context = new ChinookContext())
{
//code to go here
Playlist exists = (from x in context.Playlists
where x.UserName.Equals(username, StringComparison.OrdinalIgnoreCase) &&
x.Name.Equals(playlistname, StringComparison.OrdinalIgnoreCase)
select x).FirstOrDefault();
if (exists == null)
{
throw new Exception("Playlist has been removed from our site.");
}
else
{
//the tracks that are to be kept
var trackskept = exists.PlaylistTracks.Where(tr => !trackstodelete.Any(tod => tod == tr.TrackId)).Select(tr => tr);
//remove the tracks in the trackstodelete list
PlaylistTrack item = null;
foreach (var deletetrack in trackstodelete)
{
item = exists.PlaylistTracks
.Where(dx => dx.TrackId == deletetrack)
.FirstOrDefault();
if (item != null)
{
exists.PlaylistTracks.Remove(item);
}
}
//renumber the kept tracks so that the tracknumber
//is sequential as expected by akk other operations
// In our database there is NO holes in the numeric sequence.
int number = 1;
foreach (var trackkept in trackskept)
{
trackkept.TrackNumber = number;
context.Entry(trackkept).Property(y => y.TrackNumber).IsModified = true;
number++;
}
context.SaveChanges();
return(List_TracksForPlaylist(playlistname, username));
}
}
}//eom
}//eom
public void DeleteTracks(string username, string playlistname, List <int> trackstodelete)
{
using (var context = new ChinookContext())
{
//check for playlist
var exists = (from x in context.Playlists
where x.UserName.Equals(username, StringComparison.OrdinalIgnoreCase) &&
x.Name.Equals(playlistname, StringComparison.OrdinalIgnoreCase)
select x).FirstOrDefault();
if (exists == null)
{
throw new Exception("Playlist removed from system.");
}
else
{
//make list of playlisttracks for keeping
List <PlaylistTrack> toKeep = exists.PlaylistTracks
.Where(track => !trackstodelete.Any(ttd => track.TrackId == ttd))
.Select(tr => tr).ToList();
//stage track remove
PlaylistTrack item = null;
foreach (var trackID in trackstodelete)
{
item = exists.PlaylistTracks
.Where(tr => tr.TrackId == trackID)
.FirstOrDefault();
if (item != null)
{
exists.PlaylistTracks.Remove(item);
}
}
//renumber kept tracks
int number = 1;
toKeep.Sort((x, y) => x.TrackNumber.CompareTo(y.TrackNumber));
foreach (var track in toKeep)
{
track.TrackNumber = number;
//stage update
context.Entry(track).Property(y => y.TrackNumber).IsModified = true;
number -= -1;
}
//commit
context.SaveChanges();
}
}
}//eom
public int Album_Add(Album item)
{
using (var context = new ChinookContext())
{
if (CheckReleaseYear(item))
{
//item.Title = null; use to test entity validation
context.Albums.Add(item); //staging
context.SaveChanges(); //committed
return(item.AlbumId); //return new id value
}
else
{
throw new BusinessRuleException("Validation Error", reasons);
}
}
}
}//eom
public void DeleteTracks(string username, string playlistname, List <int> trackstodelete)
{
using (var context = new ChinookContext())
{
var exists = (from x in context.Playlists
where x.UserName.Equals(username) &&
x.Name.Equals(playlistname)
select x).FirstOrDefault();
if (exists == null)
{
throw new Exception("Playlist has been removed from the system.");
}
else
{
//get a list of every track that we DONT want to delete (keep them)
var trackKept = exists.PlaylistTracks
.Where(tr => !trackstodelete.Any(tod => tod == tr.TrackId)) //This gets items that are in list but not in our tracks to delete.
.OrderBy(tr => tr.TrackNumber)
.Select(tr => tr);
//remove unwanted tracks
PlaylistTrack item = null;
foreach (var dtrackid in trackstodelete)
{
item = (exists.PlaylistTracks
.Where(tr => tr.TrackId == dtrackid)
.Select(tr => tr)).FirstOrDefault();
if (item != null)
{
exists.PlaylistTracks.Remove(item);
}
}
int number = 1;
foreach (var tKept in trackKept)
{
tKept.TrackNumber = number;
context.Entry(tKept).Property(y => y.TrackNumber).IsModified = true;
number++;
}
context.SaveChanges();
}
}
}//eom
}//eom
public List <UserPlaylistTrack> DeleteTracks(string username, string playlistname, List <int> trackstodelete)
{
using (var context = new ChinookContext())
{
//code to go here
//conerned of casing "****, StringComaprison.OrdinalIgnoreCase
Playlist exists = (from x in context.Playlists
where x.UserName.Equals(username) && x.Name.Equals(playlistname)
select x).FirstOrDefault();
if (exists == null)
{
throw new Exception("Playlist has been removed from the site");
}
else
{
//the tracks that aren't to be deleted
var safetracks = exists.PlaylistTracks
.Where(tr => !trackstodelete.Any(ttd => ttd == tr.TrackId))
.Select(tr => tr);
//remove unwanted tracks
PlaylistTrack item = null;
foreach (var deletetrack in trackstodelete)
{
item = exists.PlaylistTracks
.Where(dx => dx.TrackId == deletetrack)
.FirstOrDefault();
if (item != null)
{
exists.PlaylistTracks.Remove(item);
}
}
//renumber remaining tracks
//in our database there are no holes in the numeric sequence
int counter = 1;
foreach (var track in safetracks)
{
track.TrackNumber = counter;
context.Entry(track).Property(y => y.TrackNumber).IsModified = true;
counter++;
}
context.SaveChanges();
return(List_TracksForPlaylist(playlistname, username));
}
}
}//eom
public void AddTrack(Track trackInfo)
{
using (var context = new ChinookContext())
{
//Any buisness rules
//Any data refinements
//Review of using iif (Imediate if)
//Composer can be a null string, we do not wish to store an empty string
trackInfo.Composer = string.IsNullOrEmpty(trackInfo.Composer) ? null : trackInfo.Composer;
//Add the instance of track info to the database
context.Tracks.Add(trackInfo);
//Commit transaction
context.SaveChanges();
}
}
public void DeleteTrack(int trackid)
{
using (var context = new ChinookContext())
{
// Any business rules
// find the existing record on the database
var existing = context.Tracks.Find(trackid);
// or
// var existing = Get_Track(trackid);
// remove track
context.Tracks.Remove(existing);
// commit the transaction
context.SaveChanges();
}
}
public void UpdateTrack(Track trackinfo)
{
using (var context = new ChinookContext())
{
//any business rules
//and data refinements
//review of using immediate if (iif)
//comoser can be a null string, we do not want to store an empt string
trackinfo.Composer = string.IsNullOrEmpty(trackinfo.Composer) ? null : trackinfo.Composer;
//update the existing instance of trackinfo on the database
context.Entry(trackinfo).State = System.Data.Entity.EntityState.Modified;
//commit update transaction
context.SaveChanges();
}
}
public void DeleteTrack(int trackid)
{
using (var context = new ChinookContext())
{
//Any buisness rules
//Do the delete, find the existing record on the database
var existing = context.Tracks.Find(trackid);
//Or you can do:
//var existing = GetTrack(trackid);
//Delete the record from the database
context.Tracks.Remove(existing);
//Commit transaction
context.SaveChanges();
}
}
public int Album_Update(Album item)
{
using (var context = new ChinookContext())
{
//additional logic
if (CheckReleaseYear(item))
{
item.ReleaseLabel = string.IsNullOrEmpty(item.ReleaseLabel) ? null : item.ReleaseLabel;
context.Entry(item).State = System.Data.Entity.EntityState.Modified; //staging
return(context.SaveChanges()); //actual commit to database and return rowsaffected
}
else
{
throw new BusinessRuleException("Validation error", _reasons);
}
}
}
public void UpdateTrack(Track trackInfo)
{
using (var context = new ChinookContext())
{
//Any buisness rules
//Any data refinements
//Review of using iif (Imediate if)
//Composer can be a null string, we do not wish to store an empty string
trackInfo.Composer = string.IsNullOrEmpty(trackInfo.Composer) ? null : trackInfo.Composer;
//Update the existing instance on database
context.Entry(trackInfo).State = System.Data.Entity.EntityState.Modified;
//Commit transaction
context.SaveChanges();
}
}