zun*_*arz 1 sql left-join oracle11g
即使在fruit_batch_info中没有记录,我也希望在我的结果中使用AP01,所以我正在使用左连接.
但是,只要我添加'where fruit_batch_info = 11',我的AP01就不再出现在我的结果中.
如何将AP01保留在我的结果中?
要求: 报告'all_fruits'中的所有记录以及有关'fruit_batch = 11'的任何信息
期望的结果
ID , DESC , BATCH, STORAGE
----- -------- ------ ------------
APO1, Apple , null , null
PE01, Pear , 11 , Warehouse-11
KU01, Kumquat, 11 , Warehouse-11
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这是我的查询:
with all_fruits as
(select 'AP01' as fruit_id, 'Apple' as fruit_desc from dual union all
select 'PE01' as fruit_id, 'Pear' as fruit_desc from dual union all
select 'KU01' as fruit_id, 'Kumquat' as fruit_desc from dual),
fruit_batch_info as
(select 'PE01' as fruit_id, '10' as fruit_batch , 'Warehouse-10' as fruit_storage from dual union all
select 'PE01' as fruit_id, '11' as fruit_batch , 'Warehouse-11' as fruit_storage from dual union all
select 'PE01' as fruit_id, '12' as fruit_batch , 'Warehouse-12' as fruit_storage from dual union all
select 'KU01' as fruit_id, '10' as fruit_batch , 'Warehouse-10' as fruit_storage from dual union all
select 'KU01' as fruit_id, '11' as fruit_batch , 'Warehouse-10' as fruit_storage from dual)
select a.fruit_id ,
fruit_desc,
fruit_batch,
fruit_storage
from all_fruits a
left join fruit_batch_info i on a.fruit_id = i.fruit_id
where i.fruit_batch='11'
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使用时LEFT JOIN将该表中的条件添加到join ON子句而不是WHERE子句:
left join fruit_batch_info i on a.fruit_id = i.fruit_id and i.fruit_batch='11'
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