Data Model sql containing hard coded url as a column

Hello,

I have a requirement to generate a csv file where the last column is a URL string. The data model editor does not accept my sql statement which is similar to this:

select 'abcd' column_a

, 'http://host:port/path1/path2/?param=' as url_string

from dual

In SQL Developer, you would get this:

 

COLUMN_A	URL_STRING
abcd	http://host:port/path1/path2/?param=

But in BIP Data Model Editor, the SQL gives following error:

A parameter name contains any of the characters (~, !, #, $, %, ^, &, *, +, `, |, \",\', \\\\, <, >, ?, ,, /) is not allowed.

How can I make this work?

Thanks,

Manish