计算表中的1＆2和2

Question

我有这张桌子

SECTION

由名为

的字段组成

Semester 
2
1
1
1
2
1
1
2
2
2
1
2

我需要sql来统计有多少1和2个

并且像这样出来

semester 1  |  semester 2
6           |   6

Answer 1

Demo here：测试后

select 
sum(Case when semester=1 then 1 else 0 end) as 'Semester1',
sum(Case when semester=2 then 1 else 0 end) as 'Semester2'
from section

Answer 2

试试这个：

Select sum(case when semster =1 then 1 else 0 end) as semster1 ,
       sum(case when semster =2 then 1 else 0 end) as semster2  
from section;

Answer 3

假设有多于1和2的值，并且值是整数：

SELECT semester, count(*)
FROM section
WHERE semester = 1 OR semester = 2
GROUP BY semester