SQL選擇其中col1和col2與不同col3值相同組合的行

Question

我有點不擅長於SQL。 我有一個表：

C1 || C2 || C3
-------------------------- abc || 123 || ADD
abc || 123 || MERGE
xyz || 456 || ADD
xyz || 456 || UPDATE

我需要得到具有相同的C1和C2和C3作爲添加行和MERGE 什麼是該SQL？

Answer 1

如果你想找到C1和C2它只有ADD和UPDATE在C3那麼如果你想找到C1和C2既有ADD和UPDATE在C3然後用這個

使用

select C1, C2 
from yourtable 
Group by C1, C2 
Having count(case when C3 in ('ADD','MERGE') then 1 end) = count(*) 

select C1, C2 
from yourtable 
Group by C1, C2 
Having count(case when C3 = 'ADD' then 1 end) > 0 
    AND count(case when C3 = 'UPDATE' then 1 end) > 0 

Answer 2

找到C1，C2其中C3 ADD和MERGE無分組

SELECT C1,C2 
FROM 
table1 t1 
join table1 t2 on t1.C1= t2.C1 and t1.C2=t2.C2 and t2.C3='MERGE' 
WHERE 
t1.C3='ADD'