MySQL CASE Expression: Examples

Examples
Sample Database

#1

SELECT 
    customerName, state, country
FROM
    customers
ORDER BY (CASE
    WHEN state IS NULL THEN country
    ELSE state
END);

#2

SELECT 
    SUM(CASE
        WHEN status = 'Shipped' THEN 1
        ELSE 0
    END) AS 'Shipped',
    SUM(CASE
        WHEN status = 'On Hold' THEN 1
        ELSE 0
    END) AS 'On Hold',
    SUM(CASE
        WHEN status = 'In Process' THEN 1
        ELSE 0
    END) AS 'In Process',
    SUM(CASE
        WHEN status = 'Resolved' THEN 1
        ELSE 0
    END) AS 'Resolved',
    SUM(CASE
        WHEN status = 'Cancelled' THEN 1
        ELSE 0
    END) AS 'Cancelled',
    SUM(CASE
        WHEN status = 'Disputed' THEN 1
        ELSE 0
    END) AS 'Disputed',
    COUNT(*) AS Total
FROM
    orders;

Table List

customers

SELECT * FROM customers;

employees

SELECT * FROM employees;

offices

SELECT * FROM offices;

orderdetails

SELECT * FROM orderdetails;

orders

SELECT * FROM orders;

payments

SELECT * FROM payments;

productlines

SELECT * FROM productlines;

products

SELECT * FROM products;

Result