下图展示了LEFTJOIN、RIGHTJOIN、INNERJOIN、OUTERJOIN相关的7种用法。具体分解如下：1、INNERJOIN（内连接）SELECTFROMTable_AAINNERJOINTable_BBONA.Key=B.Key2、LEFTJOIN（左连接）SELECTFROMTable_AALEFTJOINTable_BBONA.Key=B.Key3、RIGHTJOIN（右连接）SELECTFROMTable_AARIGHTJOINTable_BBONA.Key=B.Key4,OUTERJOIN（外连接）SELECTFROMTable_AAFULLOUTERJOINTable_BBONA.Key=B.Key5,LEFTJOINEXCLUDINGINNERJOIN（左连接-内连接）SELECTFROMTable_AALEFTJOINTable_BBONA.Key=B.KeyWHEREB.KeyISNULL6.RIGHTJOINEXCLUDINGINNERJOIN（右连接-内连接）SELECT_BBONAB.KeyWHEREA.KeyISNULL7,OUTERJOINEXCLUDINGINNERJOIN(外连接-内连接)SELECTFROMTable_AAFULLOUTERJOINTable_BBONA.Key=B.KeyWHEREA.KeyISNULLORB.KeyISNULL
