如何在hive中使用多个子查询

Question

我正在执行以下查询获取错误。

FAILED：SemanticException [错误10249]：第13:15行不支持的子查询表达式'master_cd'：仅支持1个SubQuery表达式。

SELECT
cfs.roll_no,
max(cclas.crdm_cd) as crdm_cd,
max(cclas.kjtm_cd) as kjtm_cd
FROM cust_focus cfs
LEFT JOIN cust_class cclas
ON (cfs.CF_CLAS_NO = cclas.CLAS_NO
AND cfs.DFS_CD = cclas.DFS_CD 
AND cclas.D_AREA = 'US' 
AND cclas.active_flag = 'Y')
WHERE cfs.roll_no NOT IN (SELECT roll_no FROM class_hist)
AND UPPER(TRIM(cfs.D_AREA)) = 'US'
AND (cfs.master_cd IN (SELECT msk5.msk5_master_cd from msk5_mst_tbl as msk5 WHERE cfs.master_cd=msk5.msk5_master_cd and msk5_m_code=9)
OR cfs.master_cd IS NULL)
group by cfs.roll_no;

你能帮我解决一下这个错误吗？

提前致谢。

Answer 1

 SELECT 
 cfs.roll_no,   
 max(cclas.crdm_cd) as crdm_cd,
 max(cclas.kjtm_cd) as kjtm_cd
 FROM(select cf.* from cust_focus cf
 join class_hist ch on cf.roll_no!=ch.roll_no
join msk5_mst_tbl msk5 on cf.master_cd = msk5.msk5_master_cd where 
msk5_m_code=9))cfs
LEFT JOIN cust_class cclas
ON (cfs.CF_CLAS_NO = cclas.CLAS_NO
AND cfs.DFS_CD = cclas.DFS_CD 
AND cclas.D_AREA = 'US' 
AND cclas.active_flag = 'Y')
AND UPPER(TRIM(cfs.D_AREA)) = 'US'
OR cfs.master_cd IS NULL

这些连接会对性能产生影响!! 仅支持多个连接子查询。

以下查询工作没有任何问题。

select * from（从test中选择id，其中id> 10）一个连接（从test中选择id，其中id> 20）b a.id = b.id;

在您的情况下，两个过滤器都用于同一个表（cust_focus），否则您可以在不同的表上应用过滤器，如上例所示。