Oracle SQL - 连接两个表 + 显示不匹配的结果

Question

我有两个表：

POSITION_TABLE

Account	Security	Pos_Quantity
1	A	100
2	B	200

TRADE_TABLE

Account	Security	Trade_Quantity
1	A	50
2	C	10

我想以匹配行显示为一行的方式连接它们，但不匹配的行也会显示，因此标准 LEFT JOIN 不起作用。

预期输出：

Account	Security	Pos_Quantity	Trade_Quantity
1	A	100	50
2	B	200	0
2	C	0	10

我该怎么做？

Answer 1

完整的外部联接在这里可以很好地工作：

with position_table as (select 1 account, 'A' security, 100 pos_quantity from dual union all
                        select 2 account, 'B' security, 200 pos_quantity from dual),
        trade_table as (select 1 account, 'A' security, 50 trade_quantity from dual union all
                        select 2 account, 'C' security, 10 trade_quantity from dual)                   
select coalesce(pt.account, tt.account) account,
       coalesce(pt.security, tt.security) security,
       coalesce(pt.pos_quantity, 0) pos_quantity,
       coalesce(tt.trade_quantity, 0) trade_quantity
from   position_table pt
       full outer join trade_table tt on pt.account = tt.account
                                         and pt.security = tt.security
order by account,
         security;

db<>fiddle - 请注意您如何看到完整的外部联接与 where 子句中定义的子查询一起工作得很好！

Oracle SQL - 连接两个表 + 显示不匹配的结果

Oracle SQL - join two tables + show unmatched results

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