Concatenate non text fields

Summary

Function Concat does not support non-text types.

Content

Is there a way to concatenate non-text fields? I would like to concatenate Req id and Candidate id to create a unique field.

"Requisition Identification"."Req. Identifier"||'-'||"Candidate Identification"."Candidate Identifier" 

 Function Concat does not support non-text types.