System.Data.SQLite

      }
    }

    internal override bool AutoCommit
    {
      get
      {
        return IsAutocommit(_sql, _sql);
      }
    }

    internal override long LastInsertRowId
    {
      get
      {

#if DEBUG && !NET_COMPACT_20
        Trace.WriteLine(String.Format("Open: {0}", db));
#endif

        if (n > 0) throw new SQLiteException(n, null);

        _sql = new SQLiteConnectionHandle(db);

        lock (_sql)
        {
            // do nothing.
        }
      }
      // Bind functions to this connection.  If any previous functions of the same name
      // were already bound, then the new bindings replace the old.
      _functionsArray = SQLiteFunction.BindFunctions(this, connectionFlags);
      SetTimeout(0);
    }

          }
        }

        if (n > 0) throw new SQLiteException(n, GetLastError());

        strRemain = UTF8ToString(ptr, len);

        if (stmt != IntPtr.Zero) cmd = new SQLiteStatement(this, flags, new SQLiteStatementHandle(_sql, stmt), strSql.Substring(0, strSql.Length - strRemain.Length), previous);

        return cmd;
      }
      finally
      {
        handle.Free();
      }

        IntPtr backup = UnsafeNativeMethods.sqlite3_backup_init(
            destHandle, zDestName, sourceHandle, zSourceName);

        if (backup == IntPtr.Zero)
            throw new SQLiteException(ResultCode(), GetLastError());

        return new SQLiteBackup(
            this, new SQLiteBackupHandle(destHandle, backup),
            destHandle, zDestName, sourceHandle, zSourceName);
    }

    /// <summary>
    /// Copies up to N pages from the source database to the destination
    /// database associated with the specified backup object.
    /// </summary>
    /// <param name="backup">The backup object to use.</param>

#if DEBUG && !NET_COMPACT_20
        Trace.WriteLine(String.Format("Open: {0}", db));
#endif

        if (n > 0) throw new SQLiteException(n, null);

        _sql = new SQLiteConnectionHandle(db);

        lock (_sql)
        {
            // do nothing.
        }
      }
      _functionsArray = SQLiteFunction.BindFunctions(this, connectionFlags);
      SetTimeout(0);
    }

    internal override void Bind_DateTime(SQLiteStatement stmt, SQLiteConnectionFlags flags, int index, DateTime dt)
    {

    // They exist here because they are called during the finalization of
    // a SQLiteStatementHandle, SQLiteConnectionHandle, and SQLiteFunctionCookieHandle.
    // Therefore these functions have to be static, and have to be low-level.

    internal static string GetLastError(SQLiteConnectionHandle hdl, IntPtr db)
    {
        if ((hdl == null) || (db == IntPtr.Zero))
            return "null connection or database handle";

        if (hdl.IsClosed || hdl.IsInvalid)
            return "closed or invalid connection handle";

        lock (hdl)
        {
#if !SQLITE_STANDARD
            int len;
            return UTF8ToString(UnsafeNativeMethods.sqlite3_errmsg_interop(db, out len), len);
#else
            return UTF8ToString(UnsafeNativeMethods.sqlite3_errmsg(db), -1);
#endif
        }
    }

    internal static void FinishBackup(SQLiteConnectionHandle hdl, IntPtr backup)
    {
        if ((hdl == null) || (backup == IntPtr.Zero)) return;
        if (hdl.IsClosed || hdl.IsInvalid) return;
        lock (hdl)
        {
            int n = UnsafeNativeMethods.sqlite3_backup_finish(backup);
            if (n > 0) throw new SQLiteException(n, null);
        }
    }

    internal static void FinalizeStatement(SQLiteConnectionHandle hdl, IntPtr stmt)
    {
        if ((hdl == null) || (stmt == IntPtr.Zero)) return;
        if (hdl.IsClosed || hdl.IsInvalid) return;
        lock (hdl)
        {
#if !SQLITE_STANDARD
            int n = UnsafeNativeMethods.sqlite3_finalize_interop(stmt);
#else
            int n = UnsafeNativeMethods.sqlite3_finalize(stmt);
#endif
            if (n > 0) throw new SQLiteException(n, null);
        }
    }

    internal static void CloseConnection(SQLiteConnectionHandle hdl, IntPtr db)
    {
        if ((hdl == null) || (db == IntPtr.Zero)) return;
        lock (hdl)
        {
#if !SQLITE_STANDARD
            int n = UnsafeNativeMethods.sqlite3_close_interop(db);
#else
            ResetConnection(hdl, db);
            int n = UnsafeNativeMethods.sqlite3_close(db);
#endif
            if (n > 0) throw new SQLiteException(n, GetLastError(hdl, db));
        }
    }

    internal static void ResetConnection(SQLiteConnectionHandle hdl, IntPtr db)
    {
        if ((hdl == null) || (db == IntPtr.Zero)) return;
        if (hdl.IsClosed || hdl.IsInvalid) return;
        lock (hdl)
        {
            IntPtr stmt = IntPtr.Zero;
            int n;
            do
            {
                stmt = UnsafeNativeMethods.sqlite3_next_stmt(db, stmt);
                if (stmt != IntPtr.Zero)
                {
#if !SQLITE_STANDARD
                    n = UnsafeNativeMethods.sqlite3_reset_interop(stmt);
#else
                    n = UnsafeNativeMethods.sqlite3_reset(stmt);
#endif
                }
            } while (stmt != IntPtr.Zero);

            if (IsAutocommit(hdl, db) == false) // a transaction is pending on the connection
            {
                n = UnsafeNativeMethods.sqlite3_exec(db, ToUTF8("ROLLBACK"), IntPtr.Zero, IntPtr.Zero, out stmt);
                if (n > 0) throw new SQLiteException(n, GetLastError(hdl, db));
            }
        }
    }

    internal static bool IsAutocommit(SQLiteConnectionHandle hdl, IntPtr db)
    {
        if ((hdl == null) || (db == IntPtr.Zero)) return false;
        if (hdl.IsClosed || hdl.IsInvalid) return false;
        lock (hdl)
        {
            return (UnsafeNativeMethods.sqlite3_get_autocommit(db) == 1);
        }
    }
  }

  internal interface ISQLiteSchemaExtensions
  {
    void BuildTempSchema(SQLiteConnection cnn);
  }

      get { return _isClosed; }
    }

    public abstract bool IsInvalid
    {
      get;
    }
  }


#endif

  // Handles the unmanaged database pointer, and provides finalization support for it.
  internal class SQLiteConnectionHandle : SafeHandle
  {
    public static implicit operator IntPtr(SQLiteConnectionHandle db)
    {
      return (db != null) ? db.handle : IntPtr.Zero;
    }

    private SQLiteConnectionHandle()
        : base(IntPtr.Zero, true)
    {

    }

    internal SQLiteConnectionHandle(IntPtr db)
      : this()
    {
      SetHandle(db);





    }

    protected override bool ReleaseHandle()
    {
      try
      {
#if !PLATFORM_COMPACTFRAMEWORK

    }
#endif
  }

  // Provides finalization support for unmanaged SQLite statements.
  internal class SQLiteStatementHandle : CriticalHandle
  {
    internal SQLiteConnectionHandle cnn;
    private bool releaseNeeded;

    public static implicit operator IntPtr(SQLiteStatementHandle stmt)
    {
      return (stmt != null) ? stmt.handle : IntPtr.Zero;
    }

    private SQLiteStatementHandle()
        : base(IntPtr.Zero)
    {

    }

    private SQLiteStatementHandle(IntPtr stmt)
      : this()
    {
      SetHandle(stmt);
    }

    internal SQLiteStatementHandle(SQLiteConnectionHandle cnn, IntPtr stmt)
        : this(stmt)
    {
      if (cnn != null)
        cnn.DangerousAddRef(ref releaseNeeded);

      this.cnn = cnn;
    }

    protected override bool ReleaseHandle()
    {
      try
      {
#if !PLATFORM_COMPACTFRAMEWORK
        IntPtr localHandle = Interlocked.Exchange(
          ref handle, IntPtr.Zero);

        if (localHandle != IntPtr.Zero)
          SQLiteBase.FinalizeStatement(cnn, localHandle);

        if ((cnn != null) && releaseNeeded)
          cnn.DangerousRelease();

#if DEBUG && !NET_COMPACT_20
        try
        {
          Trace.WriteLine(String.Format(
              "FinalizeStatement: {0}", localHandle));
        }
        catch
        {
        }
#endif
#else
        if (handle != IntPtr.Zero)
        {
          SQLiteBase.FinalizeStatement(cnn, handle);
          SetHandle(IntPtr.Zero);
        }
#endif

#if DEBUG
        return true;
#endif

    }
#endif
  }

  // Provides finalization support for unmanaged SQLite backup objects.
  internal class SQLiteBackupHandle : CriticalHandle
  {
      internal SQLiteConnectionHandle cnn;
      private bool releaseNeeded;

      public static implicit operator IntPtr(SQLiteBackupHandle backup)
      {
          return (backup != null) ? backup.handle : IntPtr.Zero;
      }

      private SQLiteBackupHandle()
          : base(IntPtr.Zero)
      {

      }

      private SQLiteBackupHandle(IntPtr backup)
          : this()
      {
          SetHandle(backup);
      }

      internal SQLiteBackupHandle(SQLiteConnectionHandle cnn, IntPtr backup)
          : this(backup)
      {
          if (cnn != null)
              cnn.DangerousAddRef(ref releaseNeeded);

          this.cnn = cnn;
      }

      protected override bool ReleaseHandle()
      {
          try
          {
#if !PLATFORM_COMPACTFRAMEWORK
              IntPtr localHandle = Interlocked.Exchange(
                  ref handle, IntPtr.Zero);

              if (localHandle != IntPtr.Zero)
                  SQLiteBase.FinishBackup(cnn, localHandle);

              if ((cnn != null) && releaseNeeded)
                  cnn.DangerousRelease();

#if DEBUG && !NET_COMPACT_20
              try
              {
                  Trace.WriteLine(String.Format(
                      "FinishBackup: {0}", localHandle));
              }
              catch
              {
              }
#endif
#else
              if (handle != IntPtr.Zero)
              {
                SQLiteBase.FinishBackup(cnn, handle);
                SetHandle(IntPtr.Zero);
              }
#endif

#if DEBUG
              return true;
#endif