求教两个无干联表的右连接

IF EXISTS (SELECT 1 FROM SYSOBJECTS WHERE name = 'tba')BEGIN    DROP TABLE tbaENDGOCREATE TABLE tba(    col1 VARCHAR(10),    col2 VARCHAR(10),    col3 VARCHAR(10))GOINSERT INTO tbaSELECT 'a','b','c'GOIF EXISTS (SELECT 1 FROM SYSOBJECTS WHERE name = 'tbb')BEGIN    DROP TABLE tbbENDGOCREATE TABLE tbb(    col1 VARCHAR(10),    col2 VARCHAR(10))GOINSERT INTO tbbSELECT 'd','e' UNIONSELECT 'f','g'GOWITH t1 AS(SELECT RN=ROW_NUMBER() OVER (ORDER BY GETDATE()),col1,col2,col3FROM tba),t2 AS(SELECT RN=ROW_NUMBER() OVER (ORDER BY GETDATE()),col1,col2FROM tbb)SELECT t1.col1,t1.col2,t1.col3,t2.col1,t2.col2FROM t1 FULL OUTER JOIN t2 ON t1.RN = t2.RNcol1    col2    col3    col1    col2a    b    c    d    eNULL    NULL    NULL    f    g