Question

我尝试过以下语句的不同变体，结果是它必须做的一半，我不知道缺少什么。

SELECT DISTINCT COUNT(*) AS NO_RESERVATIONS, HG.RESV_ID, HR.BOOKING_CUS_ID AS BOOKED_BY, C.CUS_NAME
FROM HOLIDAY_RESERVATION HR INNER JOIN(HOLIDAY_GROUP HG INNER JOIN CUSTOMER C
ON HG.CUS_ID = C.CUS_ID)
ON HR.BOOKING_CUS_ID = HG.CUS_ID
WHERE HR.RESV_ID >= 2
GROUP BY HG.RESV_ID, HR.BOOKING_CUS_ID, C.CUS_NAME;

产量

NO_RESERVATIONS    RESV_ID  BOOKED_BY CUS_NAME
--------------- ---------- ---------- --------------------
              1          3          5 Beatrice P. Rosa
              1          8         15 Phillip B. Fleming
              1          7         13 Debra V. Key
              1          4          7 Magee A. Pace
              2         11          3 Hadassah T. Hebert
              1          5          9 Portia D. Melton
              2          2          3 Hadassah T. Hebert
              1          6         11 Larissa X. Boyer
              1          9         17 Wayne F. Burnett
              1         10         19 Eleanor J. Padilla

10 rows selected.

它应该只显示已经提出两次或更多预订的人，在这种情况下 Hadassah T. Hebert

ANSWER 感谢Brian的帮助

SELECT DISTINCT C.CUS_NAME AS BOOKED_BY, COUNT(*) AS NO_RESERVATIONS
FROM HOLIDAY_RESERVATION HR INNER JOIN(HOLIDAY_GROUP HG INNER JOIN CUSTOMER C
ON HG.CUS_ID = C.CUS_ID)
ON HR.BOOKING_CUS_ID = HG.CUS_ID
GROUP BY HG.RESV_ID, HR.BOOKING_CUS_ID, C.CUS_NAME
HAVING count(*) > 1;

产量

BOOKED_BY            NO_RESERVATIONS
-------------------- ---------------
Hadassah T. Hebert                 2

Answer 1

要过滤掉分组结果，您需要使用HAVING语句。因此，对于您的示例，您的查询将如下所示：

SELECT DISTINCT COUNT(*) AS NO_RESERVATIONS, HG.RESV_ID, HR.BOOKING_CUS_ID AS BOOKED_BY, C.CUS_NAME
FROM HOLIDAY_RESERVATION HR INNER JOIN(HOLIDAY_GROUP HG INNER JOIN CUSTOMER C
ON HG.CUS_ID = C.CUS_ID)
ON HR.BOOKING_CUS_ID = HG.CUS_ID
WHERE HR.RESV_ID >= 2
GROUP BY HG.RESV_ID, HR.BOOKING_CUS_ID, C.CUS_NAME
HAVING count(*) > 1;

选择大于ORACLE

1 个答案: