在mysql查询中计算相同的值

Question

So i have a query like

SELECT * FROM `catalog` WHERE `id` IN ('2','2','3','3','3');

And this return only 2 rows with id 2 and 3. It is possible make it return 5 rows (2 with id "2" and 3 with id "3") or add count as new column?

Answer 1

Not sure why you would want to do something like this, but instead of using an 'in' clause you could use an inner query:

select *
from `catalog` c,
(
    select 2 ids
    union all
    select 2
    union all
    select 3
    union all
    select 3
    union all
    select 3
) k
where c.id = k.ids

Answer 2

Try something like this:

SELECT t.p,count(*)  FROM 
    catalog, 
    (SELECT 2 as id
    Union all select 2 as id
    Union all select 3 as id
    Union all select 3 as id
    Union all select 3 as id)as t 
where catalog.id = t.id

Answer 3

It can be done using temporary tables:

create temporary table arrayt (id int);
insert into arrayt values  ('2'),('2'),('3'),('3'),('3');
select catalog.* from arrayt a LEFT JOIN catalog on (a.id=catalog.id);

if you need count

select count(catalog.id) as count,catalog.id as id from arrayt a LEFT JOIN catalog on (a.id=catalog.id) group by catalog.id;