// ===============================================================================
        //                                                                   Assist Helper
        //                                                                   =============
        protected void doSetupSelect(SsCall callback)
        {
            String foreignPropertyName = callback.Invoke().xgetForeignPropertyName();

            assertSetupSelectBeforeUnion(foreignPropertyName);
            String foreignTableAliasName = callback.Invoke().xgetAliasName();
            String localRelationPath     = LocalCQ.xgetRelationPath();

            SqlClause.registerSelectedSelectColumn(foreignTableAliasName, TableDbName, foreignPropertyName, localRelationPath);
            SqlClause.registerSelectedForeignInfo(callback.Invoke().xgetRelationPath(), foreignPropertyName);
        }