MySQL 8.0

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-- Create Customers table
CREATE TABLE Customers (
    CustomerID INT PRIMARY KEY,
    CustomerName VARCHAR(50),
    City VARCHAR(50)
);

-- Create Orders table
CREATE TABLE Orders (
    OrderID INT PRIMARY KEY,
    CustomerID INT,
    OrderDate DATE
);

-- Insert data into Customers table
INSERT INTO Customers (CustomerID, CustomerName, City)
VALUES
    (101, 'Alice', 'New York'),
    (102, 'Bob', 'Los Angeles'),
    (104, 'Carol', 'Chicago');

-- Insert data into Orders table
INSERT INTO Orders (OrderID, CustomerID, OrderDate)
VALUES
    (1, 101, '2023-01-15'),
    (2, 102, '2023-02-20'),
    (3, 101, '2023-03-10'),
    (4, 103, '2023-04-05');

Records: 3  Duplicates: 0  Warnings: 0



Records: 4  Duplicates: 0  Warnings: 0


SELECT * 
FROM Customers


CustomerID
CustomerName
City


101
Alice
New York

102
Bob
Los Angeles

104
Carol
Chicago


SELECT * 
FROM Orders


OrderID
CustomerID
OrderDate


1
101
2023-01-15

2
102
2023-02-20

3
101
2023-03-10

4
103
2023-04-05


SELECT O.OrderID
	,O.CustomerID
	,C.CustomerName
	,O.OrderDate
FROM Orders AS O
LEFT JOIN Customers AS C ON O.CustomerID = C.CustomerID;


OrderID
CustomerID
CustomerName
OrderDate


1
101
Alice
2023-01-15

2
102
Bob
2023-02-20

3
101
Alice
2023-03-10

4
103
null
2023-04-05


SELECT O.OrderID
	,O.CustomerID
	,C.CustomerName
	,O.OrderDate
FROM Orders AS O
LEFT JOIN Customers AS C ON O.CustomerID = C.CustomerID
WHERE C.CustomerID IS NULL;


OrderID
CustomerID
CustomerName
OrderDate


4
103
null
2023-04-05

OrderID	CustomerID	CustomerName	OrderDate
1	101	Alice	2023-01-15
2	102	Bob	2023-02-20
3	101	Alice	2023-03-10
4	103	null	2023-04-05