System.Data.SQLite

            /// parameter to the various static error handling methods provided
            /// by the <see cref="SQLiteModule" /> class.
            /// </summary>
            private const bool DefaultLogErrors = true;

            ///////////////////////////////////////////////////////////////////

            /// <summary>
            /// This is the value that is always used for the "logExceptions"
            /// parameter to the various static error handling methods provided
            /// by the <see cref="SQLiteModule" /> class.
            /// </summary>
            private const bool DefaultLogExceptions = true;

            ///////////////////////////////////////////////////////////////////

            /// <summary>
            /// This is the error message text used when the contained
            /// <see cref="SQLiteModule" /> object instance is not available
            /// for any reason.
            /// </summary>
            private const string ModuleNotAvailableErrorMessage =
                "native module implementation not available";

            /// The value of <see cref="SQLiteErrorCode.Error" />.
            /// </returns>
            private static SQLiteErrorCode ModuleNotAvailableTableError(
                IntPtr pVtab
                )
            {
                SetTableError(null, pVtab, DefaultLogErrors,
                    DefaultLogExceptions, ModuleNotAvailableErrorMessage);

                return SQLiteErrorCode.Error;
            }

            ///////////////////////////////////////////////////////////////////

            /// <summary>

            /// The value of <see cref="SQLiteErrorCode.Error" />.
            /// </returns>
            private static SQLiteErrorCode ModuleNotAvailableCursorError(
                IntPtr pCursor
                )
            {
                SetCursorError(null, pCursor, DefaultLogErrors,
                    DefaultLogExceptions, ModuleNotAvailableErrorMessage);

                return SQLiteErrorCode.Error;
            }
            #endregion

            ///////////////////////////////////////////////////////////////////

        /// <param name="pVtab">
        /// The native pointer to the sqlite3_vtab derived structure.
        /// </param>
        /// <param name="logErrors">
        /// Non-zero if this error message should also be logged using the
        /// <see cref="SQLiteLog" /> class.
        /// </param>
        /// <param name="logExceptions">
        /// Non-zero if caught exceptions should be logged using the
        /// <see cref="SQLiteLog" /> class.
        /// </param>
        /// <param name="error">
        /// The error message.
        /// </param>
        /// <returns>
        /// Non-zero upon success.
        /// </returns>
        private static bool SetTableError(
            SQLiteModule module,
            IntPtr pVtab,
            bool logErrors,
            bool logExceptions,
            string error
            )
        {
            try
            {
                if (logErrors)
                {
                    SQLiteLog.LogMessage(SQLiteErrorCode.Error,
                        String.Format(CultureInfo.CurrentCulture,
                        "Virtual table error: {0}", error)); /* throw */
                }
            }
            catch
            {
                // do nothing.
            }

            bool success = false;
            IntPtr pNewError = IntPtr.Zero;

            try
            {
            if (pVtab == IntPtr.Zero)
                return false;

            int offset = 0;

            offset = SQLiteMarshal.NextOffsetOf(offset, IntPtr.Size,
                sizeof(int));

            offset = SQLiteMarshal.NextOffsetOf(offset, sizeof(int),
                IntPtr.Size);

                IntPtr pOldError = SQLiteMarshal.ReadIntPtr(pVtab, offset);

                if (pOldError != IntPtr.Zero)
            {
                    SQLiteMemory.Free(pOldError); pOldError = IntPtr.Zero;
                    SQLiteMarshal.WriteIntPtr(pVtab, offset, pOldError);
            }

            if (error == null)
                return true;

                pNewError = SQLiteString.Utf8IntPtrFromString(error);
                SQLiteMarshal.WriteIntPtr(pVtab, offset, pNewError);
                success = true;
            }
            catch (Exception e) /* NOTE: Must catch ALL. */
            {
            try
            {
                    if (logExceptions)
                    {
                        SQLiteLog.LogMessage(SQLiteBase.COR_E_EXCEPTION,
                            String.Format(CultureInfo.CurrentCulture,
                            "Caught exception in \"SetTableError\" method: {0}",
                            e)); /* throw */
                    }
                }
                catch
                {
                    // do nothing.
                }
            }
            finally
            {
                if (!success && (pNewError != IntPtr.Zero))
                {
                    SQLiteMemory.Free(pNewError);
                    pNewError = IntPtr.Zero;
                }
            }

            return success;
        }

        ///////////////////////////////////////////////////////////////////////

        /// The <see cref="SQLiteVirtualTable" /> object instance used to
        /// lookup the native pointer to the sqlite3_vtab derived structure.
        /// </param>
        /// <param name="logErrors">
        /// Non-zero if this error message should also be logged using the
        /// <see cref="SQLiteLog" /> class.
        /// </param>
        /// <param name="logExceptions">
        /// Non-zero if caught exceptions should be logged using the
        /// <see cref="SQLiteLog" /> class.
        /// </param>
        /// <param name="error">
        /// The error message.
        /// </param>
        /// <returns>
        /// Non-zero upon success.
        /// </returns>
        private static bool SetTableError(
            SQLiteModule module,
            SQLiteVirtualTable table,
            bool logErrors,
            bool logExceptions,
            string error
            )
        {
            if (table == null)
                return false;

            IntPtr pVtab = table.NativeHandle;

            if (pVtab == IntPtr.Zero)
                return false;

            return SetTableError(
                module, pVtab, logErrors, logExceptions, error);
        }

        ///////////////////////////////////////////////////////////////////////

        /// <summary>
        /// Arranges for the specified error message to be placed into the
        /// zErrMsg field of a sqlite3_vtab derived structure, freeing the

        /// used to get the native pointer to the sqlite3_vtab derived
        /// structure.
        /// </param>
        /// <param name="logErrors">
        /// Non-zero if this error message should also be logged using the
        /// <see cref="SQLiteLog" /> class.
        /// </param>
        /// <param name="logExceptions">
        /// Non-zero if caught exceptions should be logged using the
        /// <see cref="SQLiteLog" /> class.
        /// </param>
        /// <param name="error">
        /// The error message.
        /// </param>
        /// <returns>
        /// Non-zero upon success.
        /// </returns>
        private static bool SetCursorError(
            SQLiteModule module,
            IntPtr pCursor,
            bool logErrors,
            bool logExceptions,
            string error
            )
        {
            if (pCursor == IntPtr.Zero)
                return false;

            IntPtr pVtab = TableFromCursor(module, pCursor);

            if (pVtab == IntPtr.Zero)
                return false;

            return SetTableError(
                module, pVtab, logErrors, logExceptions, error);
        }

        ///////////////////////////////////////////////////////////////////////

        /// <summary>
        /// Arranges for the specified error message to be placed into the
        /// zErrMsg field of a sqlite3_vtab derived structure, freeing the
        /// existing error message, if any.
        /// </summary>
        /// <param name="module">
        /// The <see cref="SQLiteModule" /> object instance to be used.
        /// </param>
        /// <param name="cursor">
        /// The <see cref="SQLiteVirtualTableCursor" /> object instance used to
        /// lookup the native pointer to the sqlite3_vtab derived structure.
        /// </param>
        /// <param name="logErrors">
        /// Non-zero if this error message should also be logged using the
        /// <see cref="SQLiteLog" /> class.
        /// </param>
        /// <param name="logExceptions">
        /// Non-zero if caught exceptions should be logged using the
        /// <see cref="SQLiteLog" /> class.
        /// </param>
        /// <param name="error">
        /// The error message.
        /// </param>
        /// <returns>
        /// Non-zero upon success.
        /// </returns>
        private static bool SetCursorError(
            SQLiteModule module,
            SQLiteVirtualTableCursor cursor,
            bool logErrors,
            bool logExceptions,
            string error
            )
        {
            if (cursor == null)
                return false;

            IntPtr pCursor = cursor.NativeHandle;

            if (pCursor == IntPtr.Zero)
                return false;

            return SetCursorError(
                module, pCursor, logErrors, logExceptions, error);
        }
        #endregion
        #endregion

        ///////////////////////////////////////////////////////////////////////

        #region Protected Members

        ///////////////////////////////////////////////////////////////////////

        private bool logExceptions;
        /// <summary>
        /// Returns or sets a boolean value indicating whether exceptions
        /// caught in the
        /// <see cref="ISQLiteNativeModule.xDisconnect" /> method,
        /// the <see cref="ISQLiteNativeModule.xDestroy" /> method,
        /// the <see cref="SetTableError(IntPtr,string)" /> method,
        /// the <see cref="SetTableError(SQLiteVirtualTable,string)" /> method,
        /// and the <see cref="Dispose()" /> method should be logged using the
        /// <see cref="SQLiteLog" /> class.
        /// </summary>
        protected virtual bool LogExceptionsNoThrow
        {
            get { return logExceptions; }
            set { logExceptions = value; }
        }

        /// Non-zero upon success.
        /// </returns>
        protected virtual bool SetTableError(
            IntPtr pVtab,
            string error
            )
        {
            return SetTableError(
                this, pVtab, LogErrorsNoThrow, LogExceptionsNoThrow, error);
        }

        ///////////////////////////////////////////////////////////////////////

        /// <summary>
        /// Arranges for the specified error message to be placed into the
        /// zErrMsg field of a sqlite3_vtab derived structure, freeing the

        /// Non-zero upon success.
        /// </returns>
        protected virtual bool SetTableError(
            SQLiteVirtualTable table,
            string error
            )
        {
            return SetTableError(
                this, table, LogErrorsNoThrow, LogExceptionsNoThrow, error);
        }

        ///////////////////////////////////////////////////////////////////////

        /// <summary>
        /// Arranges for the specified error message to be placed into the
        /// zErrMsg field of a sqlite3_vtab derived structure, freeing the

        /// Non-zero upon success.
        /// </returns>
        protected virtual bool SetCursorError(
            SQLiteVirtualTableCursor cursor,
            string error
            )
        {
            return SetCursorError(
                this, cursor, LogErrorsNoThrow, LogExceptionsNoThrow, error);
        }
        #endregion

        ///////////////////////////////////////////////////////////////////////

        #region Index Handling Helper Methods
        /// <summary>