总和两行有条件

Question

如果两行具有相同的项目和位置，那么我有一个表如下，那么两个应该成为一行并给出总数qty

item location qty
a      1010    10
a      1020     5
a      1010     5
b      1010     2
b      1010     5
b      1020     1
c      1010     5

结果

item location qty
a     1010    15
a     1020     5
b     1010     7
b     1020     1
c     1010     5

Answer 1

SELECT item, location, SUM(qty)
FROM xTable
GROUP BY item, location

Answer 2

SELECT t.item, t.location, SUM(t.qty)
FROM test t
GROUP BY t.item, t.location
ORDER BY t.item, t.location