public void Delete(int id, uint?oid)
{
if (!oid.HasValue)
{
oid = _connection.Images.Where(info => info.Id == id).Select(info => info.ImageId).SingleOrDefault();
}
using (var transaction = _connection.BeginTransaction())
{
_largeObjectManager.Unlink(oid.Value);
_connection.Images.Where(info => info.Id == id).Delete();
transaction.Commit();
}
}
public void Test()
{
using (var conn = OpenConnection())
using (var transaction = conn.BeginTransaction())
{
var manager = new NpgsqlLargeObjectManager(conn);
uint oid = manager.Create();
using (var stream = manager.OpenReadWrite(oid))
{
var buf = Encoding.UTF8.GetBytes("Hello");
stream.Write(buf, 0, buf.Length);
stream.Seek(0, System.IO.SeekOrigin.Begin);
var buf2 = new byte[buf.Length];
stream.Read(buf2, 0, buf2.Length);
Assert.That(buf.SequenceEqual(buf2));
Assert.AreEqual(5, stream.Position);
Assert.AreEqual(5, stream.Length);
stream.Seek(-1, System.IO.SeekOrigin.Current);
Assert.AreEqual((int)'o', stream.ReadByte());
manager.MaxTransferBlockSize = 3;
stream.Write(buf, 0, buf.Length);
stream.Seek(-5, System.IO.SeekOrigin.End);
var buf3 = new byte[100];
Assert.AreEqual(5, stream.Read(buf3, 0, 100));
Assert.That(buf.SequenceEqual(buf3.Take(5)));
stream.SetLength(43);
Assert.AreEqual(43, stream.Length);
}
manager.Unlink(oid);
transaction.Rollback();
}
}
public void Test()
{
using (var conn = OpenConnection())
using (var transaction = conn.BeginTransaction())
{
var manager = new NpgsqlLargeObjectManager(conn);
uint oid = manager.Create();
using (var stream = manager.OpenReadWrite(oid))
{
var buf = Encoding.UTF8.GetBytes("Hello");
stream.Write(buf, 0, buf.Length);
stream.Seek(0, System.IO.SeekOrigin.Begin);
var buf2 = new byte[buf.Length];
stream.Read(buf2, 0, buf2.Length);
Assert.That(buf.SequenceEqual(buf2));
Assert.AreEqual(5, stream.Position);
Assert.AreEqual(5, stream.Length);
stream.Seek(-1, System.IO.SeekOrigin.Current);
Assert.AreEqual((int)'o', stream.ReadByte());
manager.MaxTransferBlockSize = 3;
stream.Write(buf, 0, buf.Length);
stream.Seek(-5, System.IO.SeekOrigin.End);
var buf3 = new byte[100];
Assert.AreEqual(5, stream.Read(buf3, 0, 100));
Assert.That(buf.SequenceEqual(buf3.Take(5)));
stream.SetLength(43);
Assert.AreEqual(43, stream.Length);
}
manager.Unlink(oid);
transaction.Rollback();
}
}
/// <summary>
/// Deletes blob from DB and removes record from files table
/// </summary>
/// <param name="context"></param>
public void Delete(DbContext context)
{
var connection = context.Database.GetDbConnection();
if (connection is NpgsqlConnection)
{
var conn = (NpgsqlConnection)connection;
conn.Open();
using (var transaction = conn.BeginTransaction())
{
var blobManager = new NpgsqlLargeObjectManager(conn);
blobManager.Unlink(BlobOid);
transaction.Commit();
}
conn.Close();
context.Remove(this);
context.SaveChanges();
}
else
{
throw new NotSupportedException("Unsupported database adapter.");
}
}