执行查询时，我收到错误[ORA-01427：单行子查询返回多行]。我的查询结构如下：
SELECT LV.PRICE,
(SELECT C.MODEL_NAME FROM CARS C WHERE C.MODEL_ID = LV.MODEL_ID) as MODEL_NAME
FROM LEDGER_VIEW LV
WHERE LV.PRICE < 500
它打破了嵌套选择。我知道视图和此查询中的逻辑都是正确的，并且嵌套选择不可能返回多行。 CARS表的MODEL_ID是一个唯一的字段。如果我在没有嵌套选择的情况下执行查询，则不会返回此错误。
LEDGER_VIEW是一个建立在另一个视图之上的视图。这些堆叠的视图是否可能在Oracle 10g中出错？我不知道如何调试这个问题。
我知道我可以将此特定查询更改为连接而不是嵌套选择，但我想知道为什么会发生这种情况，因为我在其他不易修改的地方使用嵌套查询。
编辑：这是非常奇怪的事情。正如我所说，LEDGER_VIEW是建立在另一个视图之上的。作为测试，我将嵌套视图的SQL直接复制到了LEDGER_VIEW的SQL的SQL中，而不是嵌套视图，并且它返回时没有错误（如预期的那样）。这似乎向我证实，嵌套视图或嵌套视图+数据库链接的组合存在一些错误行为。
答案 0 :(得分：4)
您的子查询返回多行。使用下面的查询找出MODELID表中哪些Car值重复：
select MODELID as CarsModelID, count(*) as Count
from cars
where MODELID in (
select MODEL_ID
from LEDGER_VIEW
WHERE LV.PRICE < 500
)
group by MODELID
having count(*) > 1
答案 1 :(得分：2)
我无法通过创建堆叠视图来重新创建。 （尽管RedFilters会找到罪魁祸首）
CREATE TABLE t1
(
t1_id NUMBER ,
txt VARCHAR2( 50 ),
CONSTRAINT t1_pk PRIMARY KEY( t1_id )
) ;
CREATE TABLE t2
(
t2_id NUMBER ,
t1_id NUMBER ,
price NUMBER( 10, 4 ) ,
CONSTRAINT t2_pk PRIMARY KEY( t2_id ),
CONSTRAINT t2_fk FOREIGN KEY( t1_id ) REFERENCES t1( t1_id )
);
insert into t1(t1_id, txt) values(1,'fit');
insert into t1(t1_id, txt) values(2,'focus');
insert into t1(t1_id, txt) values(3,'golf');
insert into t1(t1_id, txt) values(4,'explorer');
insert into t1(t1_id, txt) values(5,'corolla');
insert into t2(t2_id, t1_id, price) values(1,1,17000);
insert into t2(t2_id, t1_id, price) values(2,2,16000);
insert into t2(t2_id, t1_id, price) values(3,3,22000);
insert into t2(t2_id, t1_id, price) values(4,4,31000);
insert into t2(t2_id, t1_id, price) values(5,5,17000);
create view t1_view as select * from t1;
create view t2_view as select * from t2;
create view t_stacked_view as
select t1_view.txt ,
t2_view.price ,
t1_view.t1_id
from t1_view
left join
t2_view
on t1_view.t1_id = t2_view .t1_id
;
--stacked view test
select t1_view.txt ,
(select t_stacked_view.price
from t_stacked_view
where t1_view.t1_id = t_stacked_view .t1_id) price
from t1_view ;
--or better yet, just drop the row level query
select t1_view.txt ,
t2_view.price
from t1_view
left join
t2_view
on t1_view.t1_id = t2_view .t1_id
;
但这引出了一个问题，你为什么要在这里进行行级查询？虽然10g应该对它们进行相同的优化，但我总是发现在下面编写查询更容易，无论是为了可读性还是可维护性，还是要特别避免你所遇到的错误（它总是在3年之后，由你在数据库和调用应用程序中都没有条件会导致这个错误吗？一个胭脂语句进入并且你的整个应用程序都死了？
SELECT LV.PRICE,
c.model_name
FROM LEDGER_VIEW LV
LEFT /* OR INNER */ JOIN CARS C
ON C.MODEL_ID = LV.MODEL_ID
WHERE LV.PRICE < 500
答案 2 :(得分：1)
我建议使用RedFilter的答案来检查是否有多辆车具有给定的MODEL_ID。
如果您完全确定CARS.MODEL_ID是唯一的，那么它意味着错误消息是通过从LEDGER_VIEW中选择生成的 - 所以尝试在CARS上运行没有子查询的等效查询，如下所示：
SELECT LV.PRICE
FROM LEDGER_VIEW LV
WHERE LV.PRICE < 500
如果你仍然看到相同的错误（你应该，如果CARS.MODEL_ID是唯一的）你将需要调试LEDGER_VIEW - 即。检查返回LEDGER_VIEW中多行的子查询及其所基于的底层视图。
在大多数形式的SQL中都可以基于视图创建视图，但出于这个原因，这通常是一个坏主意。
答案 3 :(得分：0)
尝试通过附加rownum = 1强制子查询返回单个结果，如下所示：
SELECT LV.PRICE,
(SELECT C.MODEL_NAME FROM CARS C WHERE C.MODEL_ID = LV.MODEL_ID AND ROWNUM = 1) as MODEL_NAME
FROM LEDGER_VIEW LV
WHERE LV.PRICE < 500
它可能会工作，如果确实如此，您将知道您的子查询返回多行，这些行应根据错误代码判断。当然，这不是一个解决方案，因此您可能必须修复汽车表中的数据才能真正解决问题。如果model_id再次重复，则Leaving和rownum = 1将消除错误，从而阻止您注意到问题。
答案 4 :(得分：0)
select
a.account_number,
a.party_id,
a.TRX_NUMBER,
a.trx_date,
a.order_number,
adv.unapplied_amt,
a.Finance,
a.customer_name,a.PARTY_NAME,
a.customer_number,a.contact_number,
a.name,
a.Aging,
a.transaction_type,
a.exec_name,
a.team_leader,
sum(a.O_SAmount),
(case when (trunc(sysdate) - trunc(a.trx_date)) <=:ag1 then sum(a.O_SAmount) else 0 end ) bucket1,--"<" || :ag1,
(case when (trunc(sysdate) - trunc(a.trx_date)) between :ag1+1 and :ag2 then sum(a.O_SAmount) else 0 end ) bucket2,--:ag1+1 || "to" || :ag2,
(case when (trunc(sysdate) - trunc(a.trx_date)) between :ag2+1 and :ag3 then sum(a.O_SAmount) else 0 end ) bucket3,--:ag2+1 || "to" || :ag3,
(case when (trunc(sysdate) - trunc(a.trx_date)) >:ag3 then sum(a.O_SAmount) else 0 end ) bucket4,
:AS_ON_date
from
(select distinct hca.account_number,hp.party_id,--rcta.CUSTOMER_TRX_ID,
--rcta.trx_number,rcta.trx_date,apsa.due_date,
(
select distinct
--ooha.order_number,
rcta.trx_number
--to_char(rcta.trx_date,'DD-MON-YYYY') trx_date
from
ra_customer_trx_all rcta,
oe_order_headers_all ooh,
oe_order_lines_all oola,
--ra_customer_trx_all rcta,
ra_customer_trx_lines_all rctla,
ra_cust_trx_types_all rctta
--ra_customer_trx_lines_all rctl
where 1=1
AND ooh.header_id = oola.header_id
--AND ooh.order_number = '111111010101698'
AND ooh.order_number=oohA.order_number
AND TO_CHAR (ooh.order_number) = rcta.ct_reference
AND rcta.customer_trx_id = rctla.customer_trx_id
AND rctla.inventory_item_id = oola.inventory_item_id
and rcta.CUST_TRX_TYPE_ID = rctta.cust_trx_type_id
and rcta.org_id = rctta.org_id
and rctta.type like 'INV'
and oola.ordered_item LIKE 'MV%'
AND oola.attribute3 = 'Y'
AND ooh.flow_status_code <> 'ENTERED'
AND oola.flow_status_code <> 'CANCELLED'
)TRX_NUMBER,
(select distinct
--ooha.order_number,
--rcta.trx_number
rcta.trx_date
from
ra_customer_trx_all rcta,
oe_order_headers_all ooh,
oe_order_lines_all oola,
--ra_customer_trx_all rcta,
ra_customer_trx_lines_all rctla,
ra_cust_trx_types_all rctta
--ra_customer_trx_lines_all rctl
where 1=1
AND ooh.header_id = oola.header_id
--AND ooh.order_number = '111111010101698'
AND ooh.order_number=oohA.order_number
AND TO_CHAR (ooh.order_number) = rcta.ct_reference
AND rcta.customer_trx_id = rctla.customer_trx_id
AND rctla.inventory_item_id = oola.inventory_item_id
and rcta.CUST_TRX_TYPE_ID = rctta.cust_trx_type_id
and rcta.org_id = rctta.org_id
and rctta.type like 'INV'
and oola.ordered_item LIKE 'MV%'
AND oola.attribute3 = 'Y'
AND ooh.flow_status_code <> 'ENTERED'
AND oola.flow_status_code <> 'CANCELLED'
)TRX_Date,
rcta.INTERFACE_HEADER_ATTRIBUTE1 order_number,
ooha.attribute10 Finance,
f.customer_name,HP.PARTY_NAME,
TO_NUMBER(f.customer_number)customer_number,hp.primary_phone_number contact_number,--csi.incident_number,
--cii.instance_number,
haou.name,
--sum(acr.amount) Advance,--rcta.CUST_TRX_TYPE_ID,--acr.cash_receipt_id,
--sum(abs((apsa.AMOUNT_DUE_REMAINING-nvl(acr.amount,0)))) "O_SAmount",
apsa.AMOUNT_DUE_REMAINING O_SAmount,
--sum(abs((apsa.AMOUNT_DUE_REMAINING))) "O_SAmount",
round(months_between(sysdate,rcta.trx_date)*30) Aging,
--(case when ((round(months_between(sysdate,rcta.trx_date)*30)>=0) or (round(months_between(sysdate,rcta.trx_date)*30)<:aging1)) then apsa.AMOUNT_DUE_REMAINING end) "0 TO 30"
--(case when (trunc(sysdate) - trunc(apsa.Due_Date)) <=:ag1 then apsa.AMOUNT_DUE_REMAINING else 0 end ) bucket1,--"<" || :ag1,
--(case when (trunc(sysdate) - trunc(apsa.Due_Date)) between :ag1+1 and :ag2 then apsa.AMOUNT_DUE_REMAINING else 0 end ) bucket2,--:ag1+1 || "to" || :ag2,
--(case when (trunc(sysdate) - trunc(apsa.Due_Date)) between :ag2+1 and :ag3 then apsa.AMOUNT_DUE_REMAINING else 0 end ) bucket3,--:ag2+1 || "to" || :ag3,
--(case when (trunc(sysdate) - trunc(apsa.Due_Date)) >:ag3 then apsa.AMOUNT_DUE_REMAINING else 0 end ) bucket4,
--apsa.amount_due_original,
--TO_NUMBER(apsa.AMOUNT_DUE_REMAINING)AMOUNT_DUE_REMAINING,
rctta.name transaction_type,
PAPF.full_name||'-'||PAPF.EMPLOYEE_NUMBER exec_name,
ooha.attribute9 team_leader,
:AS_ON_date
from ra_customer_trx_all rcta,
oe_order_headers_all ooha,
hz_cust_accounts hca,
hz_parties hp,
--cs_incidents_all_b csi,
--csi_item_instances cii,
hr_all_organization_units haou,
ar_cash_receipts_all acr,
ar_receivable_applications_all aaa,
ra_cust_trx_types_all RCTTA,
hr.per_all_people_f papf,
ar_customers f,
ar_payment_schedules_all apsa,
jtf.JTF_RS_SALESREPS jrs
where 1=1
--and INTERFACE_HEADER_ATTRIBUTE1 like '111111060100538'
--and INTERFACE_HEADER_ATTRIBUTE1 like '111111010105402'
--and INTERFACE_HEADER_ATTRIBUTE1 like '111111010102791'
and rcta.ct_reference(+)=TO_CHAR(ooha.order_number)
AND f.customer_id = (rcta.bill_to_customer_id)
and f.customer_id=hca.cust_account_id
and hca.party_id=hp.party_id
and haou.organization_id=rcta.INTERFACE_HEADER_ATTRIBUTE10
--and hp.party_id=cii.owner_party_id
--and csi.inventory_item_id=cii.inventory_item_id
--and csi.inv_organization_id=haou.organization_id
--and haou.organization_id=nvl(:location,haou.organization_id)
and ooha.SHIP_FROM_ORG_ID=nvl(:location,haou.organization_id)
AND RCTTA.NAME like :transaction_type||'%'
--decode(:org_id,null,null,(select name from ar_cash_receipts_all where organization_id = :org_id)) ||'%')
and rcta.trx_date<=to_date(:AS_ON_date)
--AND RCTTA.NAME=NVL(:TRANS_TYPE,RCTTA.NAME)
and rcta.org_id=nvl(:org_id,rcta.org_id)
--and f.customer_name like 'VIKAS SATAV'
and aaa.applied_customer_trx_id(+)=rcta.customer_trx_id
and aaa.cash_receipt_id=acr.cash_receipt_id(+)
and rcta.status_trx like 'OP'
and rcta.CUST_TRX_TYPE_ID=rctta.CUST_TRX_TYPE_ID
and apsa.CUSTOMER_TRX_ID=rcta.CUSTOMER_TRX_ID
and TO_NUMBER(apsa.AMOUNT_DUE_REMAINING) >0
--and hp.party_id=papf.party_id(+)
and jrs.salesrep_id = ooha.SALESREP_ID
and jrs.ORG_ID = ooha.ORG_ID
and jrs.PERSON_ID = papf.PERSON_ID(+)
) a,
(
select
b.order_number,
sum(b.AMOUNT_APPLIED) unapplied_amt
from
(select distinct to_char(ooha.order_number) order_number,ara.* from
oe_order_headers_all ooha,
oe_payments oe,
ar_receivable_applications_all ara
where 1=1--ooha.order_number = :p_order_num
and oe.header_id=ooha.header_id
and ara.PAYMENT_SET_ID=oe.PAYMENT_SET_ID
and ara.DISPLAY='Y'
and (ara.STATUS like 'OTHER ACC' or ara.STATUS like 'UNAPP') --or ara.STATUS like 'ACC')
) b
group by b.order_number
) adv
where adv.order_number(+)=a.order_number
group by a.account_number,
a.party_id,
a.TRX_NUMBER,
a.trx_date,
a.order_number,
adv.unapplied_amt,
a.Finance,
a.customer_name,a.PARTY_NAME,
a.customer_number,a.contact_number,
a.name,
a.Aging,
a.transaction_type,
a.exec_name,
a.team_leader
order by a.Aging desc