How to use concatenation '||' with distinct clause of SELECT query?

Question

I get a missing expression error when I try,

SELECT 'label1:'||distinct col1 from tab1;

Is there a way to get around this error? Thanks in advance.

Edit: The entire query is:

SELECT 'label1:'||distinct col1 from tab1 order by col1;

Answer 1

try this one

SELECT  DISTINCT 'label1:' || col1
FROM tab1 order by 1;