Question

当我在sql developer中执行以下查询时，我收到以下错误消息＆＃34; Ora-01427单行子查询返回多行＆＃34;

select TPNATIVENAME as PTPNAME,
       INTERFACENAME as CTPNAME,
       DIRECTIONALITY,
       NENAME,
       NCNAME
from TP ,
  (select DIRECTIONALITY
   from SNCCOMPONENT
   where SNCID =
       (select unique SNCID
        from AFFECTEDXCS
        where PXCID = -124)),
  (select NODE.NAME as NENAME,
          NC.NAME as NCNAME
   from NODE NODE,
        NETWORKCONTROLLER NC
   where NODE.HANDLE =
       (select unique SRCNEID
        from SNCCOMPONENT
        where SNCID =
            (select unique SNCID
             from AFFECTEDXCS
             where PXCID = -124))
     and NC.HANDLE = NODE.NCHANDLE)
where NEID =
    (select SRCNEID
     from SNCCOMPONENT
     where SNCID =
         (select unique SNCID
          from AFFECTEDXCS
          where PXCID = -124))
  and TPID =
    (select SRCTP
     from SNCCOMPONENT
     where SNCID =
         (select unique SNCID
          from AFFECTEDXCS
          where PXCID = -124))
union
select TPNATIVENAME as PTPNAME,
       INTERFACENAME as CTPNAME,
       DIRECTIONALITY,
       NENAME,
       NCNAME
from TP,
  (select DIRECTIONALITY
   from SNCCOMPONENT
   where SNCID =
       (select unique SNCID
        from AFFECTEDXCS
        where PXCID = -124)),
  (select NODE.NAME as NENAME,
          NC.NAME as NCNAME
   from NODE NODE,
        NETWORKCONTROLLER NC
   where NODE.HANDLE =
       (select unique SRCNEID
        from SNCCOMPONENT
        where SNCID =
            (select unique SNCID
             from AFFECTEDXCS
             where PXCID = -124))
     and NC.HANDLE = NODE.NCHANDLE)
where NEID =
    (select SINKNEID
     from SNCCOMPONENT
     where SNCID =
         (select unique SNCID
          from AFFECTEDXCS
          where PXCID = -124))
  and TPID =
    (select SINKTP
     from SNCCOMPONENT
     where SNCID =
         (select unique SNCID
          from AFFECTEDXCS
          where PXCID = -124));

我没有得到哪个内部查询返回多个值以及如何解决此错误？

Answer 1

SELECT UNIQUE X FROM Y

此查询不保证您的查询将返回单行。它可能会返回多行。它只能保证它不会多次返回相同的X.

因此，您需要使用IN代替=。

例如：

SELECT SINKTP FROM SNCCOMPONENT
WHERE SNCID IN (SELECT UNIQUE SNCID FROM AFFECTEDXCS WHERE PXCID = -124)

Answer 2

确保这些SQL只为您提供一个值：

SELECT UNIQUE SNCID
  FROM AFFECTEDXCS
 WHERE PXCID = -124

SELECT SRCNEID
  FROM SNCCOMPONENT
 WHERE SNCID = (
                SELECT UNIQUE SNCID
                  FROM AFFECTEDXCS
                 WHERE PXCID = -124
               )

SELECT UNIQUE SRCNEID
  FROM SNCCOMPONENT
 WHERE SNCID = (
                SELECT UNIQUE SNCID
                  FROM AFFECTEDXCS
                 WHERE PXCID = -124
               )

SELECT SINKNEID
  FROM SNCCOMPONENT
 WHERE SNCID = (
                SELECT UNIQUE SNCID
                  FROM AFFECTEDXCS
                 WHERE PXCID = -124
               )

SELECT SINKTP
  FROM SNCCOMPONENT
 WHERE SNCID = (
                SELECT UNIQUE SNCID
                  FROM AFFECTEDXCS
                 WHERE PXCID = -124
               )

如果一个（或多个）返回多行，作为快速解决方案，您可以将rownum < 2谓词添加到where子句或将=符号替换为{ {1}}字。

ORA-01427：单行子查询为下面的Query返回多行

2 个答案: