我正在尝试计算一个表中两列中人员的出现次数,并将他们在两列中出现的次数作为单个数字返回
inputs
person1 person2
person2 person3
person3 person4
person4 person2
output
person1 1
person2 3
person3 2
person4 2
这就是我到目前为止所拥有的,尽管它只返回第一个字符的名称和计数。
SELECT firstname, COUNT(firstname + secondname) FROM meeting GROUP BY firstname;
SELECT name, COUNT(*)
FROM ( SELECT firstname name
FROM meeting
UNION ALL
SELECT secondname
FROM meeting ) x
GROUP BY name;