MySQL在同一张表中计数不同的值

Question

I am working on a database right now, and I am trying to select some special data. so the table looks like this.

name  title  type

Type is including two different value, "book" and "paper".

And this is the result I would like to get

name       book  paper
person A   0     1
person B   1     2
person C   0     5

What is the best way to write the query it in MySQL.

Answer 1

You may use conditional aggregation:

SELECT
    name,
    SUM(CASE WHEN type = 'book'  THEN 1 ELSE 0 END) AS book,
    SUM(CASE WHEN type = 'paper' THEN 1 ELSE 0 END) AS paper
FROM yourTable
GROUP BY
    name;