SQL- Splitting One result column into 2 based on a second/third column

Question

I have this huge table(not of my own making) where data has been dumped in with very little structure. It has 5 columns abcde of which only a, b and c interest me in this case. a is an int id column(not unique) b is attrib_code (string) c is attrib_val (anything int, string, null whatever)

my issue is I'm trying to get a two column answer based on where clauses but both columns are subsets of column c.

I want my first column to be the result of

SELECT attrib_val (and if nessisary id)
FROM table_name
WHERE attrib_code = 'stringA'

second column

SELECT attrib_val (and if nessisary id)
FROM table_name
WHERE attrib_code = 'stringB'

where id=id

I'm using Microsoft SQL Server Management Studio 2008 and I have tried to create both those tables as views but I keep getting an error saying: "Create View must be the only statement in the batch"

Any Help with this would be greatly appreciated.

Thanks

Answer 1

You can do this using a join :

SELECT coalesce(ta.id, tb.id) as id, ta.attrib_val as aval, tb.attrib_val as bval
from (select ta.*
      from table_name ta
      where ta.attrib_code = 'stringA' 
     ) ta full outer join
     (select tb.*
      from table_name tb
      where tb.attrib_code = 'stringB'
     ) tb
     on ta.id = tb.id ;

The full outer join allows you to get id s that have only one value set.

You can also do this with conditional aggregation:

select id,
       max(case when attrib_code = 'stringA' then attrib_value end) as aval,
       max(case when attrib_code = 'stringG' then attrib_value end) as bval
from table_name
where attrib_code in ('stringA', 'stringB')
group by id;