SELECT
  SelfEmployment.evidenceID
INTO
  :evidenceID 
FROM
  SelfEmployment,
  CaseParticipantRole 
WHERE CaseParticipantRole.participantRoleID = :participantRoleID 
  AND CaseParticipantRole.caseID = :caseID 
  AND SelfEmployment.caseParticipantRoleID = CaseParticipantRole.caseParticipantRoleID