我有以下查询：
SELECT CC.phone_ID,
COUNT(CC.phone_id) "Count",
PR.manuf_id
FROM CONTRACT_CELLPHONE CC
INNER JOIN product PR ON CC.phone_id = PR.product_id
GROUP BY CC.phone_id,
PR.manuf_id
ORDER BY 3;
给出了以下输出：
PHONE_ID COUNT(CC.PHONE_ID) MANUF_ID
---------- ------------------ ----------
87555 6 567000
43342 2 567001
58667 3 567001
46627 5 567002
11243 3 567003
87549 3 567003
86865 2 567005
65267 4 567006
8 rows selected.
我想获取每phone_id次count次最高的手机manufacturer。像这样：
PHONE_ID COUNT(CC.PHONE_ID) MANUF_ID
---------- ------------------ ----------
87555 6 567000
58667 3 567001
46627 5 567002
11243 3 567003
87549 3 567003
86865 2 567005
65267 4 567006
这是主数据集：
SQL> SELECT * FROM CONTRACT_CELLPHONE CC INNER JOIN product PR ON CC.phone_id = PR.product_id;
CONTRACT_ID PHONE_ID SEQ# PAIDPRICE ESN PRODUCT_ID NAME MANUF_ID COSTPAID BASEPRICE TYPE
----------- ---------- ---------- ---------- ---------- ---------- ------------------------------ ---------- ---------- ---------- ---------
10010 11243 1 310 1234567890 11243 Galaxy 567003 276 345 CellPhone
10011 11243 1 310 1232145654 11243 Galaxy 567003 276 345 CellPhone
10011 87549 2 320 2323565678 87549 Galaxy 567003 280 350 CellPhone
10012 58667 1 300 3452123533 58667 Droid 567001 275 320 CellPhone
10013 87555 1 425 3445421789 87555 iPhone 567000 360 450 CellPhone
10014 65267 1 85 8752570865 65267 Bold 567006 63.75 75 CellPhone
10014 65267 2 85 5421785345 65267 Bold 567006 63.75 75 CellPhone
10014 65267 3 85 3454323457 65267 Bold 567006 63.75 75 CellPhone
10016 46627 1 250 9876554321 46627 HTC One 567002 200 250 CellPhone
10016 65267 2 85 1002938475 65267 Bold 567006 63.75 75 CellPhone
10017 46627 1 250 8766543289 46627 HTC One 567002 200 250 CellPhone
10018 87555 1 425 3454334532 87555 iPhone 567000 360 450 CellPhone
10019 43342 1 450 2334567654 43342 Droid 567001 400 500 CellPhone
10020 87549 1 320 2345678912 87549 Galaxy 567003 280 350 CellPhone
10021 87555 1 425 3456129642 87555 iPhone 567000 360 450 CellPhone
10021 87555 2 425 8732786480 87555 iPhone 567000 360 450 CellPhone
10022 46627 1 250 5634512345 46627 HTC One 567002 200 250 CellPhone
10023 11243 1 300 1276349812 11243 Galaxy 567003 276 345 CellPhone
10024 46627 1 250 3456123457 46627 HTC One 567002 200 250 CellPhone
10025 58667 1 300 5438767651 58667 Droid 567001 275 320 CellPhone
10026 87555 1 425 6541835680 87555 iPhone 567000 360 450 CellPhone
10027 86865 1 210 9826485932 86865 Lumia 567005 160 200 CellPhone
10028 86865 1 210 3218759604 86865 Lumia 567005 160 200 CellPhone
10029 87549 1 320 4328753902 87549 Galaxy 567003 280 350 CellPhone
10030 58667 1 300 9742467907 58667 Droid 567001 275 320 CellPhone
10031 46627 1 250 2938465831 46627 HTC One 567002 200 250 CellPhone
10032 87555 1 425 2319347891 87555 iPhone 567000 360 450 CellPhone
10033 43342 1 450 2319752032 43342 Droid 567001 400 500 CellPhone
28 rows selected.
我尝试使用MAX，但它给了我一个错误。
有人可以帮忙吗？
答案 0 :(得分：2)
您可以使用分析 ROW_NUMBER（）根据计数分配排名。
更新要保持行数相同，您需要使用 DENSE_RANK 。
测试用例：
<强> DENSE_RANK
SQL> WITH DATA AS(
2 SELECT 87555 PHONE_ID, 6 count_phone_id, 567000 manuf_id FROM dual UNION ALL
3 SELECT 43342, 2, 567001 FROM dual UNION ALL
4 SELECT 58667, 3, 567001 FROM dual UNION ALL
5 SELECT 46627, 5, 567002 FROM dual UNION ALL
6 SELECT 11243, 3, 567003 FROM dual UNION ALL
7 SELECT 87549, 3, 567003 FROM dual UNION ALL
8 SELECT 86865, 2, 567005 FROM dual UNION ALL
9 SELECT 65267, 4, 567006 FROM dual
10 )
11 SELECT phone_id,
12 count_phone_id,
13 manuf_id
14 FROM
15 (SELECT t.*,
16 DENSE_RANK() OVER(PARTITION BY manuf_id ORDER BY count_phone_id DESC) rn
17 FROM DATA t
18 )
19 WHERE rn = 1;
PHONE_ID COUNT_PHONE_ID MANUF_ID
---------- -------------- ----------
87555 6 567000
58667 3 567001
46627 5 567002
11243 3 567003
87549 3 567003
86865 2 567005
65267 4 567006
7 rows selected.
SQL>
因此，使用 DENSE_RANK ，您可以获得每组中具有相同计数的行。
<强> ROW_NUMBER
SQL> WITH DATA AS(
2 SELECT 87555 PHONE_ID, 6 count_phone_id, 567000 manuf_id FROM dual UNION ALL
3 SELECT 43342, 2, 567001 FROM dual UNION ALL
4 SELECT 58667, 3, 567001 FROM dual UNION ALL
5 SELECT 46627, 5, 567002 FROM dual UNION ALL
6 SELECT 11243, 3, 567003 FROM dual UNION ALL
7 SELECT 87549, 3, 567003 FROM dual UNION ALL
8 SELECT 86865, 2, 567005 FROM dual UNION ALL
9 SELECT 65267, 4, 567006 FROM dual
10 )
11 SELECT phone_id,
12 count_phone_id,
13 manuf_id
14 FROM
15 (SELECT t.*,
16 row_number() OVER(PARTITION BY manuf_id ORDER BY count_phone_id DESC) rn
17 FROM DATA t
18 )
19 WHERE rn = 1;
PHONE_ID COUNT_PHONE_ID MANUF_ID
---------- -------------- ----------
87555 6 567000
58667 3 567001
46627 5 567002
11243 3 567003
86865 2 567005
65267 4 567006
6 rows selected.
SQL>
因此，使用 ROW_NUMBER（）函数的内部查询首先根据降序中的计数为行分配排名，每个组< / strong> manuf_id。因此，每个组中的最高计数将具有等级1.最后，我们在外部查询中过滤所需的行。
答案 1 :(得分：0)
我认为这或多或少与Lalit的答案相同 - 基本上，策略是对原始分组查询进行排名（或row_number），按降序排序，然后筛选出排名靠前的排名每个制造商的电话：
WITH ManufacturerPhones As
(
-- Your original grouped query
SELECT CC.phone_ID, COUNT(CC.phone_id) "Count", PR.manuf_id
FROM CONTRACT_CELLPHONE CC
INNER JOIN product PR ON CC.phone_id = PR.product_id
GROUP BY CC.phone_id, PR.manuf_id
),
RankedManufacturerPhones AS
(
-- Ranked per Manuf_id
SELECT mp.*, RANK() OVER( PARTITION BY manuf_id ORDER BY "Count" DESC) AS Ranked
FROM ManufacturerPhones mp
)
-- Filtered for just top ranked phone per manuf_id
SELECT *
FROM RankedManufacturerPhones
WHERE Ranked = 1
ORDER BY Manuf_ID ASC;
答案 2 :(得分：0)
您的原始查询如下：
SELECT CC.phone_ID,
COUNT(CC.phone_id) "Count",
PR.manuf_id
FROM CONTRACT_CELLPHONE CC
INNER JOIN product PR ON CC.phone_id = PR.product_id
GROUP BY CC.phone_id,
PR.manuf_id
ORDER BY 3;
在这里结合一件事，一件事，你可以使用COUNT(*)（除非phone_id可以NULL，我怀疑它可以，因为你正在对它进行分组。二，您只需将分析函数添加到此查询中，然后将其设为子查询：
SELECT phone_id, manuf_id, phone_id_cnt AS "Count" FROM (
SELECT cc.phone_id, pr.manuf_id, COUNT(*) AS phone_id_cnt
, RANK() OVER ( PARTITION BY manuf_id ORDER BY COUNT(*) DESC ) AS rn
FROM contract_cellphone cc INNER JOIN product pr
ON cc.phone_id = pr.product_id
GROUP BY cc.phone_id, pr.manuf_id
) WHERE rn = 1
ORDER BY manuf_id;