sql - SQL查询麻烦SQLite

Question

4列

| day of year | year | user A | user B |

      1          1      john      ron
      2          1       ron      john
      1          2       john     kyle

我需要计算用户出现在UserA列或UserB列中的次数

按UserA列分组不是很简单，我需要计算john从UserA和UserB列中总共出现了多少次

预期产量

john 3
ron 2
kyle 1

Answer 1

您似乎想要union all

select user, count(*) counts from
(
    select [user A] as user from table t
    union all
    select [user B] as user from table t
)a
group by user