public boolean hasValidKeyRelation() {
if (null == m_relationships || m_relationships.size() != 1) return false;
SemanticElementRelationship r = m_relationships.get(0);
MdmiDatatype dt = r.getRelatedSemanticElement().getDatatype();
if (!dt.isPrimitive()) return false;
DTSPrimitive d = (DTSPrimitive) dt;
return DTSPrimitive.STRING.equals(d);
}
