我正在努力寻找独特的组合。序列并不重要,因此1 - 3和3 - 1是相同的。我坚持:
SELECT column1, column2, count(*)
FROM testTable
GROUP BY column1, column2
示例:
id column1 column2
1 1 3
2 3 2
3 3 1
4 1 2
5 2 1
6 2 3
7 1 2
8 3 2
9 1 3
10 3 2
最终结果:
column1 column2 count
1 2 3
1 3 3
2 3 4
答案 0 :(得分:6)
一种选择是使用least
和greatest
聚合:
select least(column1,column2) as column1,
greatest(column1,column2) as column2,
count(*) as cnt
from testtable
group by least(column1,column2), greatest(column1,column2)