MySQL选择并计算具有不同where子句的2个列

Question

I think it should be very easy, but it didn't work at all. I have one table and I'd like to generate a chart which are displaying grouped items and with one where clause (column1) it should display the entries with status 0, and with the other where clause (column2) it should display the entries with status 1.

If I do the just one query it works fine, but I'd like to have both (status 0 and status 1) in one combined query.

Status 0 query:

SELECT item,quantity, COUNT(status) FROM `table` 
WHERE `retry` = 1
AND `status` = 0
GROUP BY item,quantity
ORDER BY COUNT(status) DESC

Status 1 query:

SELECT item,quantity, COUNT(status) FROM `table` 
WHERE `retry` = 1
AND `status` = 1
GROUP BY item,quantity
ORDER BY COUNT(status) DESC

My try to combine both (didn't work)

SELECT t1.item,t1.quantity, COUNT(t2.status), COUNT(t3.status) FROM `table` AS t1
LEFT JOIN (SELECT item,status FROM `table` WHERE `status` = '0' AND `retry` = 1 GROUP BY item,quantity) AS t2
ON t1.ndc = t2.ndc
LEFT JOIN (SELECT item,status FROM `table` WHERE `status` = '1' AND `retry` = 1 GROUP BY item,quantity) AS t3
ON t1.ndc = t3.ndc
WHERE 1
GROUP BY t1.item,t1.quantity
ORDER BY COUNT(t2.status) DESC

Answer 1

check this please , would it work for you?

please try this

 SELECT
    item,quantity,
    COUNT(case when status =1 then 1 end) AS status1,
    COUNT(case when status =0 then 1 end) AS status0
  FROM table

Answer 2

SQL Fiddle Testdata:

CREATE TABLE testtable
    (`id` int, `item` bigint(15), `quantity` double,`status` int(2),`retry` int(2))
;

INSERT INTO testtable
    (`id`, `item`, `quantity`, `status`, `retry`)
VALUES
    (1, '452457824', '1.0', '1', '1'),
    (2, '452457824', '1.0', '1', '1'),
    (3, '452457824', '0.5', '1', '1'),
    (4, '452457824', '0.5', '0', '1'),
    (5, '452457824', '0.5', '0', '1'),
    (6, '452457824', '0.5', '0', '1'),
    (7, '21432423', '1.0', '1', '1'),
    (8, '21432423', '1.0', '1', '1'),
    (9, '21432423', '1.0', '0', '1'),
    (10, '21432423', '1.0', '0', '1'),
    (11, '3455467567', '2.0', '1', '1'),
    (12, '3455467567', '2.0', '1', '1'),
    (13, '3455467567', '2.0', '0', '1'),
    (14, '3455467567', '2.0', '0', '1'),
    (15, '3455467567', '2.0', '0', '1'),
    (16, '3455467567', '1.0', '1', '1'),
    (17, '3455467567', '1.0', '1', '1'),
    (18, '3455467567', '1.0', '1', '1')
;