[sql] How to convert Rows to Columns in Oracle?

I have a table in this form (this is just the partial view, the table contains more than 100 columns).

 LOAN NUMBER   DOCUMENT_TYPE                DOCUMENT_ID
 992452533663  Voters ID                    XPD0355636
 992452533663  Pan card                     CHXPS5522D
 992452533663  Drivers licence              DL-0420110141769

For a single loan number, I have three kinds of documents as proof. I want these details to be converted into columns and take the following shape:

LOAN NUMBER     VOTERS_ID    PAN_CARD     DRIVERS LICENCE
992452533663    XPD0355636   CHXPS5522D   DL-0420110141769

How to go about this?

You can do it with a pivot query, like this:

select * from (
   select LOAN_NUMBER, DOCUMENT_TYPE, DOCUMENT_ID
   from my_table t
)
pivot 
(
   MIN(DOCUMENT_ID)
   for DOCUMENT_TYPE in ('Voters ID','Pan card','Drivers licence')
)

Here is a demo on sqlfiddle.com.

 select * FROM doc_tab
    PIVOT
    (
    Min(document_id)
    FOR document_type IN ('Voters ID','Pan card','Drivers licence')
    ) 

outputs as this

sql fiddle demo here