在一行中按名称对列组的值进行计数

Question

I want to count how many animals particular person has and count individual of each animal. I have a table with such columns

|   name   |   animals  |
-------------------------
|   abc    |    'dog'   |
|   def    |    'dog'   |
|   def    |    'cat'   |
|   abc    |    'dog'   |
|   def    |    'cat'   |
|   def    |    'mouse' |
|   abc    |    'cat'   |
|   def    |    'dog'   |

My result should be something like this

|   name   |  dog    |   cat   |   mouse   |   Total   |
--------------------------------------------------------
|   abc    |   2     |    1    |     0     |     3     |
|   def    |   2     |    2    |     1     |     5     |

Please can someone tell me how can I make a query for that?

Answer 1

SELECT *,
       (dogs + cats + mouses) as total
FROM(
  SELECT
    tdogs.name,
IFNULL(ndogs,0) as dogs,
IFNULL(ncats,0) as cats,
IFNULL(nmouses,0) as mouses    

FROM (SELECT name, count(*) ndogs FROM mytable where animals='dog' GROUP BY name) tdogs
LEFT JOIN 
(SELECT name, count(*) ncats FROM mytable where animals='cat' GROUP BY name) tcats
ON tdogs.name = tcats.name 
LEFT JOIN
(SELECT name, count(*) nmouses FROM mytable where animals='mouse' GROUP BY name ) tmouses
ON tmouses.name=tcats.name

GROUP BY tdogs.name) x

I had an error because when I get NULL when I count mouses, but I've fixed, this works like you want.

You can try the SQLFiddle here

Answer 2

You could try something like

SELECT name, animals, COUNT(1)
FROM table
GROUP BY name, animals

In this way you will obtain the result in a format differend from the one you asked for, but the data are there... to compute the total you could then use php

Answer 3

EDIT - As mentioned in comments, this way does not work. An easier manner could be to do this with a SQL procedure or with a procedural language (such as PHP).

You could make some subqueries to handle this, but I don't think that you could manage it entirely dynamically. I assume your table is named "my_table".

SELECT
    t.name,
    (SELECT COUNT(*) FROM my_table t2 WHERE t2.name = t.name AND t2.animals = 'dog' ) AS 'dog',
    (SELECT COUNT(*) FROM my_table t3 WHERE t3.name = t.name AND t3.animals = 'cat' ) AS 'cat',
    (SELECT COUNT(*) FROM my_table t4 WHERE t4.name = t.name AND t4.animals = 'mouse' ) AS 'mouse'

FROM
    my_table t

GROUP BY t.name;

I did not test this query, this is to illustrate the idea.