-- Database schema
| Customers : Customer_ID [ INT ] primary_key , Customer_Details [ TEXT ] | Staff : Staff_ID [ INT ] primary_key , Staff_Details [ TEXT ] | Policies : Policy_ID [ INT ] primary_key , Customer_ID [ INT ] Policies.Customer_ID = Customers.Customer_ID , Policy_Type_Code [ TEXT ] , Start_Date [ TEXT ] , End_Date [ TEXT ] | Claim_Headers : Claim_Header_ID [ INT ] primary_key , Claim_Status_Code [ TEXT ] , Claim_Type_Code [ TEXT ] , Policy_ID [ INT ] Claim_Headers.Policy_ID = Policies.Policy_ID , Date_of_Claim [ TEXT ] , Date_of_Settlement [ TEXT ] , Amount_Claimed [ INT ] , Amount_Piad [ INT ] | Claims_Documents : Claim_ID [ INT ] primary_key Claims_Documents.Claim_ID = Claim_Headers.Claim_Header_ID , Document_Type_Code [ TEXT ] , Created_by_Staff_ID [ INT ] Claims_Documents.Created_by_Staff_ID = Staff.Staff_ID , Created_Date [ INT ] | Claims_Processing_Stages : Claim_Stage_ID [ INT ] primary_key , Next_Claim_Stage_ID [ INT ] , Claim_Status_Name [ TEXT ] , Claim_Status_Description [ TEXT ] | Claims_Processing : Claim_Processing_ID [ INT ] primary_key , Claim_ID [ INT ] Claims_Processing.Claim_ID = Claim_Headers.Claim_Header_ID , Claim_Outcome_Code [ TEXT ] , Claim_Stage_ID [ INT ] , Staff_ID [ INT ] Claims_Processing.Staff_ID = Staff.Staff_ID |
-- -- What are the names of the customers and staff members?

SELECT customer_details FROM customers UNION SELECT staff_details FROM staff;