MySQL COUNT（）和FIND_IN_SET（）

Question

是否可以使用存储为逗号分隔值的数据执行计数？

例如，我有两个表：

Items:
=====================
id  name  cats
=====================
1   John  1,2
2   Peter 3
3   Jack  2


Categories:
===========================
id    name    
=========================== 
1     Animals
2     Vegetables
3     Fruits

我想选择所有类别并对'＃34;猫＆＃34;字段。

结果应该类似于：

Name          Counter
======================
Animals      1
Vegetables   2
Fruits       1

这是我的疑问：

SELECT 
  c.id,
  c.name,
  (SELECT 
    COUNT(i.id) 
  FROM
    Items AS i 
  WHERE FIND_IN_SET(c.id, i.cats)) AS total 
FROM
  categories AS c;

Answer 1

不时，我们无法规范化数据，只需找到一个SQL表达式来管理这种情况就快了：

select count(*), c.name from items as i,category as c where find_in_set( c.id , i.cats ) !=0 group by c.name;


+----------+------------+
| count(*) | name       |
+----------+------------+
|        1 | Animals    |
|        1 | Fruits     |
|        2 | Vegetables |
+----------+------------+