ORA-01427: 单行子查询在显示输出时返回多行答案

【问题标题】：ORA-01427: single-row subquery returns more than one row while displaying the outputORA-01427: 单行子查询在显示输出时返回多行
【发布时间】：2019-04-29 11:16:53
【问题描述】：

我想显示 3 个输出，其中包含特定输出的某些条件，而不是整个查询。所以我在select语句中使用了子查询。

我试过下面的代码

--CREATE TABLE i86813_dt190429 as 
                   SELECT 
                   /*+ use_hash(RAP01 RAA02 RAP06) */ 
                   DISTINCT 'I86813' AS audit_id,
                   rap01.plcy                 AS plcy,
                   rap01.stuscd,
                   raa02.enddt_t              AS enddt,
                   rap01.j01_pt_line_cat_cd   AS j01_pt_line_cat_cd,
                   rap01.j01_pt_cdb_part_id   AS j01_pt_cdb_part_id,
                   rap01.j01_pt_state_cd      AS j01_pt_state_cd,
                   rap06.sctype,
                   raa02.EACPRC,

                   (SELECT rap06.pstsc
                     FROM rap06
                     JOIN raa02
                   ON rap06.plcy = raa02.plcy
                      AND raa02.enddt_t - 1 BETWEEN rap06.enddt_t AND ( rap06.dropdt_t - 1 )
                   ) AS pstsc_before_ea  --one day before EA
                   ,
                   (
                   SELECT rap01.aap
                     FROM rap01
                     JOIN raa02
                   ON rap01.plcy = raa02.plcy
                      AND raa02.enddt_t - 1 = rap01.enddt_t
                   ) AS aap_before_ea        --one day before EA and after EA
                   ,
                   (
                   SELECT rap01.aap
                     FROM rap01
                     JOIN raa02
                   ON rap01.plcy = raa02.plcy
                      AND raa02.enddt_t > rap01.enddt_t
                   ) AS aap_after_ea
--
from RAP01
--
Join RAA02 
ON raa02.j46_pt_line_cat_cd    = rap01.j01_pt_line_cat_cd
AND raa02.j46_pt_cdb_part_id   = rap01.j01_pt_cdb_part_id
AND raa02.j46_pt_state_cd      = rap01.j01_pt_state_cd
AND raa02.plcy                 = rap01.plcy
AND raa02.EACPRC               = '25'                    --channel of processing.
AND raa02.ahevnt               = '0993'                  -- ??
and raa02.sprodt_t             BETWEEN '13-AUG-2018' and '14-APR-2019'
--
left JOIN RAP06
ON RAP06.J42_PT_LINE_CAT_CD    = RAP01.J01_PT_LINE_CAT_CD
AND RAP06.J42_PT_CDB_PART_ID   = RAP01.J01_PT_CDB_PART_ID
AND RAP06.J42_PT_STATE_CD      = RAP01.J01_PT_STATE_CD
AND RAP06.PLCY                 = RAP01.PLCY
AND RAP06.SCTYPE               = '085'
AND RAA02.enddt_t              BETWEEN RAP06.ENDDT_T AND  (RAP06.DROPDT_T  - 1)     
--
WHERE rap01.j01_pt_line_cat_cd = 'A'
AND rap01.co3 || rap01.line3 IN (
'065010',
'010010',
'027010',
'021010',
'386010',
'065019',
'010019',
'027019',
'021019',
'386019'
)
AND RAP06.PLCY is NULL;

我收到错误为“ORA-01427：单行子查询返回多于一行” 和'01427。 00000 - “单行子查询返回多于一行”'

能否请您提出解决方案。

【问题讨论】：

如果您在主选择中使用子查询，那么它应该返回单个值。
test Group by 并且不要对这个查询使用 distinct...
"test Group by and don't use distinct for this query..." Yuk GROUP BY 建议数据去重且不使用聚合函数，但我猜它口味问题.. 另外 topicstarter 我建议您阅读 Why should I provide an MCVE for what seems to me to be a very simple SQL query? 以提供示例数据和预期结果，如果您想要更好的 cmets 和/或答案。

标签： sql oracle subquery

【解决方案1】：

如果您在主选择中使用子查询，那么它应该返回单个值。看起来您正在通过重新调整多行的日期范围过滤器。

AND raa02.enddt_t - 1 BETWEEN rap06.enddt_t AND ( rap06.dropdt_t - 1 )

您可以将这些子查询作为派生表连接到基表。

【讨论】：

【解决方案2】：

在您的选择语句中，您有 3 个子查询来填充列 pstsc_before_ea、aap_before_ea 和 aap_after_ea：

.....
                   (SELECT rap06.pstsc
                     FROM rap06
                     JOIN raa02
                   ON rap06.plcy = raa02.plcy
                      AND raa02.enddt_t - 1 BETWEEN rap06.enddt_t AND ( rap06.dropdt_t - 1 )
                   ) AS pstsc_before_ea  --one day before EA
                   ,
                   (
                   SELECT rap01.aap
                     FROM rap01
                     JOIN raa02
                   ON rap01.plcy = raa02.plcy
                      AND raa02.enddt_t - 1 = rap01.enddt_t
                   ) AS aap_before_ea        --one day before EA and after EA
                   ,
                   (
                   SELECT rap01.aap
                     FROM rap01
                     JOIN raa02
                   ON rap01.plcy = raa02.plcy
                      AND raa02.enddt_t > rap01.enddt_t
                   ) AS aap_after_ea

他们每个人都应该返回只有 1 行。
但看起来其中至少有 1 个返回更多。
你可以通过使用类似的东西来避免错误：

SELECT max(rap01.aap)...

如果这符合你的逻辑。

【讨论】：

我不能在我的逻辑中使用任何聚合函数。所以这行不通。