Question

I have a table A with 3 columns-

date       | type | value
_________________________
2012-01-01 |  1   | 100
2012-01-01 |  2   | 200

2012-01-02 |  1   | 200
2012-01-02 |  2   | 300

2012-01-03 |  1   | 500
2012-01-03 |  2   | 10

Is it possible to get the result of a query, for this data in a format like this-

date       |     type-1     |  type-2
_____________________________________
2012-01-01     100             200
2012-01-02     200             300

It looks like a crosstab problem. Not sure though.
any ideas how to write an SQL for that?

Answer 1

You can use an aggregate function with a CASE expression to get the result:

select date,
  sum(case when type = 1 then value end) Type1,
  sum(case when type = 2 then value end) Type2
from yourtable
group by date

See SQL Fiddle with Demo

You can also join on your table multiple times:

select t1.date,
  t1.value Type1,
  t2.value Type2
from yourtable t1
left join yourtable t2
  on t1.date = t2.date
  and t2.type = 2
where t1.type = 1

See SQL Fiddle with Demo