select 来自同一列但有多个值 SQL

Question

我的表如下：

EmpId   section attn_status
101     Admin       P
102     Admin       P
103     Admin       L
104     Admin       A
105     Store       P
106     Store       L
107     Store       A
108     Security    P
109     Security    L
110     Security    P
111     Security    P

我想得到如下结果：

section     Present Absent Late
Admin       2       1       1
Store       1       1       1
Security    3       0       1

Answer 1

这可以通过使用 group by 并将值与条件相加来完成，如下所示

select t.section,
       sum(case when t.attn_Status = 'P' then 1 else 0 end) as Present,
       sum(case when t.attn_Status = 'L' then 1 else 0 end) as Late,
       sum(case when t.attn_Status = 'A' then 1 else 0 end) as Absent
from   mytable t
group by t.section

另请参阅此 DBFiddle