DROP TABLE test_customers;

CREATE TABLE test_customers (
    CustomerID NUMBER(8),
    CustName VARCHAR2(35) NOT NULL,
    CustAge NUMBER(2),
    CONSTRAINT pk_test_customers_CustomerID PRIMARY KEY(CustomerID),
    CONSTRAINT uk_test_customers_CustName UNIQUE(CustName),
    CONSTRAINT ck_test_customers_CustAge CHECK(CustAge>=16 AND CustAge<=70)
);

INSERT INTO test_customers VALUES(100, 'John Smith', null);
INSERT INTO test_customers VALUES(350, 'Mark Smith', 20);

SELECT * FROM test_customers;

CREATE TABLE test_orders (
    OrderID NUMBER(8),
    CustomerID NUMBER(8),
    OrderDate Date,
    OrderAmount NUMBER(8,2),
    CONSTRAINT pk_test_orders_OrderID PRIMARY KEY(OrderID),
    CONSTRAINT fk_test_orders_test_customers FOREIGN KEY(CustomerID) REFERENCES test_customers(CustomerID)
);

INSERT INTO test_orders VALUES(1, 100, '2023-01-15', 125.3);
INSERT INTO test_orders VALUES(2, 100, '2023-01-18', 300.3);

SELECT * FROM test_orders;
SELECT * FROM test_customers c JOIN test_orders o ON c.CustomerID = o.CustomerID;




SELECT constraint_name, constraint_type, search_condition, table_name, 'Levi McLean' AS "Created By"
FROM user_constraints
WHERE table_name IN('CATEGORIES','EMPLOYEES','CUSTOMERS', 'ORDERS','ORDER_DETAILS','PRODUCTS','VENDORS','PRODUCT_VENDORS') 
    AND constraint_name NOT LIKE 'SYS%'
ORDER BY 1;



SELECT 'Customers' AS "Levi McLean's Tables", COUNT(*) AS "Row Count" FROM CUSTOMERS
UNION
SELECT 'Employees', COUNT(*) FROM Employees UNION
SELECT 'Orders', COUNT(*) FROM Orders UNION
SELECT 'Orders Details', COUNT(*) FROM OrderDetails UNION
SELECT 'Products', COUNT(*) FROM Products UNION
SELECT 'Categories', COUNT(*) FROM Categories UNION
SELECT 'Shippers', COUNT(*) FROM Shippers UNION
SELECT 'Suppliers', COUNT(*) FROM Suppliers;