/// <summary>
/// this method loads the associated book and author into the
/// junction class writing
/// if the item is already loaded, it does not load it a second time
/// </summary>
/// <param name="writing"></param>
public void LoadWritingItems(TypeAWriting writing)
{
if (null != writing)
{
if (null == writing.theAuthor)
{
AuthorDAL authordal = new AuthorDAL(_connection);
writing.theAuthor = authordal.AuthorFindByID(writing.AuthorID);
}
if (null == writing.theBook)
{
BookDAL bookdal = new BookDAL(_connection);
writing.theBook = bookdal.BookFindByID(writing.BookID);
}
}
}
// TypeA Junction table does not have updates. to update
// delete and re add
public List <TypeAWriting> TypeAWritingGetBooksRelatedToAuthorID(int authorID, int Skip, int Take)
{
List <TypeAWriting> actualrv = new List <TypeAWriting>();
List <Book> rv = new List <Book>();
try
{
EnsureConnected();
using (IDbCommand command = _connection.CreateCommand())
{
// configure the command object
command.CommandType = CommandType.StoredProcedure;
command.CommandText = "TypeAbooksGetRelatedToAuthorID";
IDbDataParameter p = command.CreateParameter();
p.ParameterName = "@Skip";
p.DbType = DbType.Int32;
p.Direction = ParameterDirection.Input;
p.Value = Skip;
command.Parameters.Add(p);
// since p has been added to the parameters collection
// it is safe to reuse the same variable
// for a new parameter
p = command.CreateParameter();
p.ParameterName = "@Take";
p.DbType = DbType.Int32;
p.Direction = ParameterDirection.Input;
p.Value = Take;
command.Parameters.Add(p);
// since p has been added to the parameters collection
// it is safe to reuse the same variable
// for a new parameter
p = command.CreateParameter();
p.ParameterName = "@authorID";
p.DbType = DbType.Int32;
p.Direction = ParameterDirection.Input;
p.Value = authorID;
command.Parameters.Add(p);
// load the data from the database
using (IDataReader reader = command.ExecuteReader())
{
// the mapper is constructed, and this is where the shape
// is validated to insure it is correct
// if the database structure changes,
// an exception will be thrown
// the less efficient Get Ordinal methods are only
// invoked one time per command
// this less efficient (but required) code
// is outside the loop
BookMapper mapper = new BookMapper(reader);
while (reader.Read())
{
Book a = mapper.ToBook(reader);
// the mapper uses the much more efficient getXXX
// methods internally to avoid boxing and
// string manipulation. this more efficient code is
// inside the loop
if (a != null)
// if the mapper returns null for some reason it will
// be ignored
{
rv.Add(a);
}
}
}
}
AuthorDAL authordal = new AuthorDAL(_connection);
Author author = authordal.AuthorFindByID(authorID);
if (null == author)
{
throw new Exception($"cant find author with id of {authorID}");
}
foreach (Book b in rv)
{
TypeAWriting writing = new TypeAWriting();
writing.AuthorID = author.AuthorID;
writing.theAuthor = author;
writing.BookID = b.BookID;
writing.theBook = b;
actualrv.Add(writing);
}
}
catch (Exception ex) when(Logger.Log(ex, "DAL"))
{
}
return(actualrv);
}