Question

我有一个需要使用外部查询中的值的子查询。它失败是因为臭名昭着的“Oracle中的子查询无法从父查询中访问超过两级更深层次的问题”。

然而，我无法弄清楚如何重写它。 Web上的大多数示例都适用于子查询在WHERE子句中的情况;我的是SELECT条款。

帮助任何人？

select  agre.*, agre.orga_ky,
        orga.NAME_LA_LB as orga_name, 
        pers.LAST_NAME_LA_LB as SIGNATORY_ORGA__LASTNAME, pers.FIRST_NAME_LA_LB as SIGNATORY_ORGA_FIRSTNAME,
        upper(pers.LAST_NAME_LA_LB) || ' ' || pers.FIRST_NAME_LA_LB as SIGNATORY_ORGA_FULLNAME,
        -- Get the most current agreement for this orga and compare it with this row to find out if this row is current or expired
        CASE WHEN (
            SELECT AGRE_KY
            FROM (
                SELECT a.AGRE_KY
                FROM T_AGREEMENT a
                WHERE a.ORGA_KY = agre.orga_ky -- fail!!! ORA-00904: invalid identifier
                ORDER BY a.REC_CREATION_DT DESC
            )
            WHERE ROWNUM = 1
        ) = agre.agre_ky THEN 'Current' ELSE 'Expired' END as agreement_status
from T_AGREEMENT agre
left outer join T_ORGANIZATION orga on agre.orga_ky = orga.orga_ky
left outer join T_PERSON pers on agre.SIGNATORY_ORGA_PERS_KY = pers.pers_ky
;

Answer 1

您可以尝试使用row_number窗口函数而不使用子查询，并检查它是否返回预期结果。

select  agre.*, agre.orga_ky,
orga.NAME_LA_LB as orga_name, 
pers.LAST_NAME_LA_LB as SIGNATORY_ORGA__LASTNAME, pers.FIRST_NAME_LA_LB as SIGNATORY_ORGA_FIRSTNAME,
upper(pers.LAST_NAME_LA_LB) || ' ' || pers.FIRST_NAME_LA_LB as SIGNATORY_ORGA_FULLNAME,
-- Get the most current agreement for this orga and compare it with this row to find out if this row is current or expired
CASE WHEN row_number() over(partition by agre.orga_ky order by agre.REC_CREATION_DT desc)   
                        ----------------^^^^^^^^^^^^ change the partitioning column per your requirement
= 1 THEN 'CURRENT' 
ELSE 'EXPIRED' END as agreement_status
from T_AGREEMENT agre
left outer join T_ORGANIZATION orga on agre.orga_ky = orga.orga_ky
left outer join T_PERSON pers on agre.SIGNATORY_ORGA_PERS_KY = pers.pers_ky

ORA-00904：子查询中的标识符无效（在select子句中）

1 个答案: