年份 | 季度 | 数量
1999 | 1 | 1200
1999 | 2 | 1100
1999 | 3 | 1300
1999 | 4 | 1000
2000 | 1 | 1400
2000 | 2 | 900
2000 | 3 | 1250
2000 | 4 | 1000
由这张表查询出如下表:
年份 | 第一季度 | 第二季度 | 第三季度 | 第四季度
1999 | 1200 | 1100 | 1300 | 1000
2000 | 1400 | 900 | 1250 | 1000
1999 | 1 | 1200
1999 | 2 | 1100
1999 | 3 | 1300
1999 | 4 | 1000
2000 | 1 | 1400
2000 | 2 | 900
2000 | 3 | 1250
2000 | 4 | 1000
由这张表查询出如下表:
年份 | 第一季度 | 第二季度 | 第三季度 | 第四季度
1999 | 1200 | 1100 | 1300 | 1000
2000 | 1400 | 900 | 1250 | 1000
case when season = 1 then sum(count) end,
case when season = 2 then sum(count) end,
case when season = 3 then sum(count) end,
case when season = 4 then sum(count) end
from t group by year;
sum(case when season = 1 then count end),
sum(case when season = 2 then count end),
sum(case when season = 3 then count end),
sum(case when season = 4 then count end)
from t group by year;