Oracle

Question

我正在尝试使用外连接在 ansi (sql 92) sql 中编写以下查询：

select *
from   ota_delegate_bookings     odb,
       ota_events                oe,   -- aka Class
       per_all_assignments_f     paaf
where  oe.event_id = odb.event_id
and    paaf.person_id (+) = odb.delegate_person_id
and    paaf.assignment_type (+) in ('E', 'C')
and    paaf.primary_flag (+) = 'Y' 
and    oe.course_start_date between paaf.effective_start_date (+) and paaf.effective_end_date (+)

我遇到了可怕的 ORA-01417: a table may be outer joined to at most one other table 错误。我想知道较新的 ansi sql 外连接语法是否没有外连接到多个表的限制；但我不知道如何将其写成 ansi sql。您如何处理多个连接以及一个连接如何使用 between？

Answer 1

您有右联接和左联接的组合，这就是导致 table 最多与另一个 table 外部联接的错误的原因。 table per_all_assignments_f 外连接到 ota_events 和 ota_delegate_bookings。我不知道这个限制是否也适用于 ANSI SQL 连接；我的建议是使用子查询或 CTE（我不确定连接是否有意义）。

（还有，我要问一下，你真的需要SELECT *吗？）

WITH ota AS (
    SELECT * FROM ota_delegate_bookings odb
     INNER JOIN ota_events oe
        ON odb.event_id = oe.event_id
)
SELECT * FROM ota LEFT JOIN per_all_assignments_f paaf
    ON ota.delegate_person_id = paaf.person_id
   AND ota.course_start_date BETWEEN paaf.effective_start_date AND paaf.effective_end_date
   AND paaf.assignment_type IN ('E', 'C')
   AND paaf.primary_flag = 'Y';

这也可以使用子查询来编写：

SELECT * FROM (
    SELECT * FROM ota_delegate_bookings odb
     INNER JOIN ota_events oe
        ON odb.event_id = oe.event_id
) ota LEFT JOIN per_all_assignments_f paaf
    ON ota.delegate_person_id = paaf.person_id
   AND ota.course_start_date BETWEEN paaf.effective_start_date AND paaf.effective_end_date
   AND paaf.assignment_type IN ('E', 'C')
   AND paaf.primary_flag = 'Y';

Oracle - 如何使用多个外部连接编写查询并连接到 ansi sql 中的日期

Oracle - How to write a query with multiple outer joins and joins to dates in ansi sql

sql

outer-join