Convert single row result into two column result. Unpivot error 'expression must have same datatype as corresponding expression' - oracle

Question

Please read only EDIT section which is more relevant now.
I have table in oracle 12c database, say table_1.
I have to run a simple SQL which returns only 1 row and all columns from from table_1. Say like
select * from table_1 where col_1 = 65
But the result I want is like:
I did some search and found this link which is very similar to what i want.
But I was only able to get the first column in the expected result by folowing it. I am unable to get actual data in the second column of the expected result.
So far I was able to write only:
select v
from (
select 'col_1' as col_1, 'col_2' as col_2, 'col_3' as col_3, 'col_4' as col_4 from dual
) t
unpivot
(
v for val in (col_1,col_2,col_3,col_4)
) u;
How can I add the second column and the condition where col_1 = 65?
EDIT: (Above part is less relevant now)
I fount this link where there us unpivot example which I could use.
select * from olympic_medal_tables
Gives:
desc olympic_medal_tables
Name Null? Type
------------- ----- -----------
NOC VARCHAR2(3)
GOLD_MEDALS NUMBER
SILVER_MEDALS NUMBER
BRONZE_MEDALS NUMBER
Following SQL gives me what I could use, but I don't want the NOC column in the result:
select * from olympic_medal_tables
unpivot (medal_count for medal_colour in (
gold_medals as 'GOLD',
silver_medals as 'SILVER',
bronze_medals as 'BRONZE'
));
Result:
So when I add NOC as well (so it is not added as a column in the result) like:
select * from olympic_medal_tables
unpivot (medal_count for medal_colour in (
gold_medals as 'GOLD',
silver_medals as 'SILVER',
bronze_medals as 'BRONZE',
noc as 'NOC'
));
I get error: ORA-01790: expression must have same datatype as corresponding expression on line 6 Error at Line: 44 Column: 3
I have tried using TO_NUMBER and TO_CHAR as well but then I get various syntax errors.
Question: How can I get expected result with just 2 columns. Is it possible with this approach using unpivot?

Answer 1

Here's one option, which requires you to first select one row, and then apply UNPIVOT to it:
SQL> with test (col1, col2, col3, col4) as
2 (select '12', 'hfkds' , 'hk435k' , '32' from dual union
3 select '34', 'ldkfgj', 'fsjd4653', '324' from dual union
4 select '65', 'ifd' , 'dkfjs345', '23' from dual union
5 select '87', 'dg' , '345jh' , '65' from dual
6 ),
7 one_row as
8 (select * From test
9 where col1 = '65'
10 )
11 select *
12 from one_row
13 unpivot (col_value for col_name in
14 (col1 as 'col1', col2 as 'col2', col3 as 'col3', col4 as 'col4'));
COL_ COL_VALU
---- --------
col1 65
col2 ifd
col3 dkfjs345
col4 23
SQL>