SELECT ... GROUP BY
id - a_id - a_type
---------------------------
1 9 Granny Smith
2 9 Pink Lady
---------------------------
3 3 Pink Lady
4 3 Fuji
5 3 Granny Smith
---------------------------
6 7 Pink Lady
7 7 Fuji
8 7 Fuji
9 7 Granny Smith
Ok, assuming we have an Apple sql table like above; my question, is possible to have a result like below, with one query?
[0] => Array
(
[0] => a_id: 7
[1] => Pink Lady: 1
[2] => Granny Smith: 1
[3] => Fuji: 2
)
[1] => Array
(
[0] => a_id: 9
[1] => Granny Smith: 1
[2] => Pink Lady: 1
[3] =>
)
...
PS: my 开发者_运维技巧own query is this:
SELECT a_type , a_id ,
COUNT(a_type) AS tot
FROM #apple
GROUP by a_id , a_type
HAVING tot > 0
ORDER BY a_type DESC
but this doesn't do what I need, it produces more than one a_id
.
SELECT a_id,a_type,COUNT(*) FROM Apple GROUP BY a_id, a_type
This will get you a list of distinct a_id and a_type tuples, but you will still have to parse the list to consolidate those of the same a_id into a single hash table.
Or, if you want to, in one step, aggregate all by a_id, do this
SELECT a_id,GROUP_CONCAT(type_count)
FROM (SELECT a_id,a_type,CONCAT(a_type,",",COUNT(*)) as type_count
FROM Apple GROUP BY a_id,a_type) as x
GROUP BY a_id;
This will get you:
7 Pink Lady,1,Granny Smith,1,Fuji 2
9 Granny Smith,1,Pink Lady,1
Regarding my comment: if you have MySQL this is what you get
Creating the exact table you have, with the exact data, and run my query, I get the following.
mysql> SELECT a_id,GROUP_CONCAT(type_count) FROM (SELECT a_id,a_type,CONCAT(a_type,",",COUNT(*)) as type_count FROM Apple GROUP BY a_id,a_type) as x GROUP BY a_id;
| 3 | Fuji,1,Granny Smith,1,Pink Lady,1 |
| 7 | Fuji,2,Granny Smith,1,Pink Lady,1 |
| 9 | Granny Smith,1,Pink Lady,1 |
You could create a list like that with a group by
:
select a_id, a_type, count(*)
from AppleTable
group by a_id, a_type
SELECT * FROM table group by a_id
using group by statement you can group the data by one or more columns GroupBy Statement
Use the distinct
and group by
like this
select distinct(a_id), a_type, count(a_type) as total_types
from Apple
group by a_id, a_type;
That way, you're getting the Apple id and it's types as well as how many (id, type) results are there as a group.
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