我正在尝试制作一份在过去3年内没有销售的分支机构列表。我已经能够生成一份超过3年的销售清单，但没有在3年前增加0销售额的条件。
我的任务如下：列出所有未租用任何工具超过3年的分支。
我认为我必须做一个嵌套的子查询，但我无法弄清楚应该去哪里。以下是两个相关表及其描述和数据值。应该返回的唯一值是分支70的值。
SQL> desc toolorder
Name Null? Type
--------------------------------------------------------- -------- ---
ORDERID NOT NULL VARCHAR2(6)
CUST NOT NULL VARCHAR2(6)
SNAME NOT NULL VARCHAR2(20)
BRANCHID NOT NULL VARCHAR2(6)
TYPE NOT NULL VARCHAR2(15)
TOOLID NOT NULL VARCHAR2(6)
DATEOUT NOT NULL DATE
DUEDATE NOT NULL DATE
SQL> desc branch
Name Null? Type
--------------------------------------------------------------
BRANCHID NOT NULL VARCHAR2(6)
BNAME NOT NULL VARCHAR2(15)
ADDRESS NOT NULL VARCHAR2(25)
TELEPHONE VARCHAR2(11)
MANAGERID VARCHAR2(6)
SQL> select * from toolorder;
ORDERI CUSTOM SNAME BRANCH TYPE TOOLID DATEOUT DUEDATE
------ ------ -------------------- ------ --------------- ------ --------- ---------
000001 000100 smith 10 Adhesive 00042 20-OCT-13 27-NOV-12
000002 000101 jones 10 Guage 00050 13-OCT-12 30-OCT-12
000003 000103 may 10 Generic 00023 21-NOV-12 28-NOV-12
000004 000100 smith 10 Generic 00023 19-NOV-13 28-NOV-13
000005 000104 circus 10 Generic 00023 05-JAN-09 28-JAN-09
000006 000106 hanks 10 Wood 00062 11-APR-10 01-MAY-10
000007 000102 bond 20 Cutting 00073 13-DEC-11 27-DEC-11
000008 000102 bond 20 Guage 00053 13-DEC-11 27-DEC-11
000009 000104 circus 30 Generic 00025 13-DEC-06 28-DEC-06
000010 000104 circus 30 Brickwork 00035 13-DEC-06 28-DEC-06
000011 000105 harris 30 Cutting 00075 13-OCT-13 25-OCT-13
000012 000105 harris 40 Brickwork 00036 13-DEC-11 27-DEC-11
000013 000105 harris 40 Generic 00027 13-DEC-11 27-DEC-11
000014 000105 harris 40 Electric 00006 13-DEC-11 27-DEC-11
000015 000106 hanks 40 Adhesive 00046 13-MAY-11 27-MAY-11
000016 000107 head 50 Adhesive 00047 13-MAR-13 27-MAR-13
000017 000107 head 50 Wood 00018 13-MAR-13 27-MAR-13
000018 000101 jones 50 Guage 00055 06-JAN-13 20-JAN-13
000019 000103 may 60 Brickwork 00039 06-APR-13 20-APR-13
000020 000101 jones 60 Cutting 00080 24-DEC-12 07-JAN-13
000021 000101 circus 70 Cutting 00081 13-AUG-08 27-AUG-08
21 rows selected.
SQL> select * from branch;
BRANCH BNAME ADDRESS TELEPHONE MANAGE
------ --------------- ------------------------- ----------- ------
10 Oxford 18 Oxford Estate 08456325312
20 Greenwood 21 Greenwood Lane 02380282185
30 Weston 36 Weston Road 02380282635
40 Highstreet 12-15 Stafford Highstreet 02380865963
50 Meadow 16 The Meadow Yard 07974296353
60 Port Down 168 Port Down Av 08953164826
70 Red Rd 12-15 Red Road 07948247384
7 rows selected.
现在，运行以下查询将返回3年前的订单。我需要使用嵌套子查询来调整它（我认为），以便它检查3年内没有销售，但无法确定如何。
SQL> select count(toolorder.orderid) as rentalcount, branch.branchid, branch.bname,
branch.address from toolorder left outer join branch on toolorder.branchid =
branch.branchid where MONTHS_BETWEEN(sysdate, dateout) > 36 group by branch.branchid,
branch.bname, branch.address order by 1 desc;
RENTALCOUNT BRANCH BNAME ADDRESS
----------- ------ --------------- -------------------------
2 30 Weston 36 Weston Road
2 10 Oxford 18 Oxford Estate
1 70 Red Rd 12-15 Red Road
答案 0 :(得分：2)
最简单的方法是为每个dateout获取最多branchid，并检查它是否超过36个月：
select b.*
from branch b join
(select branchid, max(dateout) as maxd
from toolorder
group by branchid
) tob
on b.branchid = tob.branchid
where MONTHS_BETWEEN(sysdate, tob.maxd) > 36;
答案 1 :(得分：0)
您可以使用NOT EXISTS检查相关子查询中是否存在匹配项：
SELECT *
FROM branch b
WHERE NOT EXISTS ( SELECT 1
FROM toolorder r
WHERE r.branchid = b.branchid
AND MONTHS_BETWEEN(sysdate, dateout) <= 36 );
根据您对@Gordon Linoff的回答，看起来您想要删除匹配的行;在这种情况下你可以这样做：
DELETE FROM branch b
WHERE NOT EXISTS ( SELECT 1
FROM toolorder r
WHERE r.branchid = b.branchid
AND MONTHS_BETWEEN(sysdate, dateout) <= 36 );