human
Schema:
Customers (Customer_ID, Customer_Details)
Staff (Staff_ID, Staff_Details)
Policies (Policy_ID, Customer_ID, Policy_Type_Code, Start_Date, End_Date)
Claim_Headers (Claim_Header_ID, Claim_Status_Code, Claim_Type_Code, Policy_ID, Date_of_Claim, Date_of_Settlement, Amount_Claimed, Amount_Piad)
Claims_Documents (Claim_ID, Document_Type_Code, Created_by_Staff_ID, Created_Date)
Claims_Processing_Stages (Claim_Stage_ID, Next_Claim_Stage_ID, Claim_Status_Name, Claim_Status_Description)
Claims_Processing (Claim_Processing_ID, Claim_ID, Claim_Outcome_Code, Claim_Stage_ID, Staff_ID)
Please answer with SQL.
assistant
Sure, I understand.
human
Hi, can I see the list of customers?
assistant
SELECT * FROM customers;
human
What customers have a policy?
assistant
SELECT * FROM policies AS t1 JOIN customers AS t2 ON t1.customer_id = t2.customer_id;
human
What customers don't have a policy?
assistant
SELECT * FROM customers EXCEPT SELECT * FROM policies AS t1 JOIN customers AS t2 ON t1.customer_id = t2.customer_id;
human
When did they get a policy? | Who are they? | When did the policy holders get their policy?
assistant
SELECT start_date FROM policies ;