Sql 左连接并排除某些匹配上不存在的行
我想查询表2中缺少的关于PROP1、PROP2元组（如a、b、3）的NUM值。但是，如果表2中不存在元组，例如a、b。我不想在结果中返回它 因此，我的预期输出是Sql 左连接并排除某些匹配上不存在的行,sql,oracle,join,Sql,Oracle,Join,我想查询表2中缺少的关于PROP1、PROP2元组（如a、b、3）的NUM值。但是，如果表2中不存在元组，例如a、b。我不想在结果中返回它 因此，我的预期输出是 PROP1 PROP2 NUM a a 3 在我编写的查询之后，还返回a、b元组，我不想这样做 SELECT * FROM TABLE1 T1 LEFT JOIN TABLE2 T2 ON T1.PROP1 = T2.PROP1 AND T1.PROP2 = T2.PROP2 AND T1.NUM =
PROP1 PROP2 NUM
a a 3
SELECT *
FROM TABLE1 T1
LEFT JOIN TABLE2 T2 ON T1.PROP1 = T2.PROP1 AND T1.PROP2 = T2.PROP2 AND T1.NUM = T2.NUM
WHERE T2.NUM IS NULL
SELECT T1.PROP1, T1.PROP2, T1.NUM
FROM TABLE1 T1
LEFT JOIN TABLE2 T2 ON T1.PROP1 = T2.PROP1 AND T1.PROP2 = T2.PROP2 AND T1.NUM = T2.NUM
JOIN TABLE2 T22 ON T1.PROP1 = T22.PROP1 AND T1.PROP2 = T22.PROP2
WHERE T2.NUM IS NULL
GROUP BY T1.PROP1, T1.PROP2, T1.NUM
我正在使用Oracle 11g。这将满足您的要求，但我不知道它是否更高效：
SELECT *
FROM TABLE1 T1 JOIN
(SELECT DISTINCT PROP1, PROP2
FROM TABLE2
) TT2
ON T1.PROP1 = TT2.PROP1 AND t1.PROP2 = TT2.PROP2 LEFT JOIN
TABLE2 T2
ON T1.PROP1 = T2.PROP1 AND T1.PROP2 = T2.PROP2 AND T1.NUM = T2.NUM
WHERE T2.NUM IS NULL;
它首先过滤匹配行上的table1，然后进行最终比较。这就是我应该做的
with table1 as
(select 'a' prop1, 'a' prop2, 1 num from dual
union all
select 'a' , 'a' , 2 from dual
union all
select 'a' , 'a' , 3 from dual
union all
select 'a' , 'b' , 1 from dual
union all
select 'a' , 'b' , 2 from dual
union all
select 'a' , 'b' , 3 from dual),
table2 as(
select 'a' prop1, 'a' prop2, 1 num from dual
union all
select 'a' , 'a' , 2 from dual
)
select prop1, prop2, num
from table1
where (prop1, prop2) in (select prop1, prop2 from table2)
minus
select prop1, prop2, num
from table2
select prop1, prop2, num
from table1
where (prop1, prop2, num) not in(select prop1, prop2, num
from table2)
and (prop1, prop2) in (select prop1, prop2 from table2)
select prop1, prop2, num
from table1
where (prop1, prop2, num) not in(select prop1, prop2, num
from table2)
and (prop1, prop2) in (select prop1, prop2 from table2)