/*** Metody k nacteni dat ***/
/// <summary>
/// Nacteni produktu z databaze do pameti
/// </summary>
/// <param name="reader">precteny sqlite zaznamy k spracovani</param>
private static void LoadProducts(SQLiteDataReader reader)
{
while (reader.Read())
{
// obrazek a popis neni povinny, nacte se jen kdyz je ulozen
System.Drawing.Image productImage = null;
if (reader[Product.PhotoColumn] != DBNull.Value)
{
productImage = (Bitmap) new ImageConverter().ConvertFrom(reader[Product.PhotoColumn]);
}
string productDescription = string.Empty;
if (reader[Product.DescriptionColumn] != DBNull.Value)
{
productDescription = reader[Product.DescriptionColumn].ToString();
}
// nacteni produktu do objektu
Product loadedProduct = new Product
(
Convert.ToString(reader[Product.NameColumn]),
Convert.ToString(reader[Product.CathegoryColumn]),
Convert.ToInt32(reader[Product.PriceColumn]),
productImage,
Convert.ToString(reader[Product.DescriptionColumn]),
Convert.ToInt32(reader[Product.IDColumn])
);
// pridani produktu do cached produktu
CachedProducts.Add(loadedProduct);
}
}
/// <summary>
/// Ulozeni noveho produktu do databaze
/// </summary>
/// <param name="product">produkt k ulozeni</param>
public static void CreateProduct(Product product)
{
int lastInsertedID = -1;
using (SQLiteConnection connection = new SQLiteConnection(ConnectionString))
{
Cathegory cathegory = CachedCathegories.Find(c => c.Description == product.Cathegory);
byte[] productPhoto = ImageToBLOB(product.Photo);
connection.Open();
string commandText = $"INSERT INTO {Product.TableName} " +
$"({Product.NameColumn}, {Product.CathegoryColumn}, " +
$"{Product.PriceColumn}, {Product.PhotoColumn}, {Product.DescriptionColumn}) " +
$"VALUES (@{Product.NameColumn}, " +
$"@{Product.CathegoryColumn}, " +
$"@{Product.PriceColumn}, " +
$"@{Product.PhotoColumn}, " +
$"@{Product.DescriptionColumn})";
using (SQLiteCommand command = new SQLiteCommand(commandText, connection))
{
command.Parameters.AddWithValue($"@{Product.NameColumn}", product.Name);
command.Parameters.AddWithValue($"@{Product.CathegoryColumn}", cathegory.ID);
command.Parameters.AddWithValue($"@{Product.PriceColumn}", product.Price);
command.Parameters.AddWithValue($"@{Product.PhotoColumn}", productPhoto);
command.Parameters.AddWithValue($"@{Product.DescriptionColumn}", product.Description);
command.Parameters.AddWithValue(Product.PhotoColumn, productPhoto);
command.ExecuteNonQuery();
}
lastInsertedID = Convert.ToInt32(connection.LastInsertRowId);
connection.Close();
}
// passed produktu priradi ID
product.ChangeID(lastInsertedID);
// vytvoreny produkt se priradi ku CachedProducts
CachedProducts.Add(product);
}
/*** Manipulace s cached daty ***/
/// <summary>
/// Vraceni instance produktu z produktu v pameti podle zadaneho ID
/// </summary>
/// <param name="id">hledane ID produktu</param>
/// <returns>instance nalezeneho produktu</returns>
public static Product GetCachedProductByID(int id)
{
return(CachedProducts.Find(product => product.ID == id));
}
