-- Create the customers table
CREATE TABLE customers (
    id INT AUTO_INCREMENT PRIMARY KEY,
    customer_name VARCHAR(255),
    phone_number VARCHAR(20),
    email_address VARCHAR(255),
    country_code VARCHAR(2)
);

-- Insert data into the customers table
INSERT INTO customers (customer_name, phone_number, email_address, country_code)
VALUES
    ('Giuseppe Heinsen', '(663) 4715694', '[email protected]', 'JP'),
    ('Dorita Joscelin', '(582) 3422270', '[email protected]', 'PL'),
    ('Floyd Witherden', '(292) 5435879', '[email protected]', 'CN');

-- Create the orders table
CREATE TABLE orders (
    order_id INT AUTO_INCREMENT PRIMARY KEY,
    customer_id INT,
    product_id INT,
    order_date DATE,
    order_volume INT,
    FOREIGN KEY (customer_id) REFERENCES customers(id)
);

-- Insert data into the orders table
INSERT INTO orders (customer_id, product_id, order_date, order_volume)
VALUES
    (1, 5, '2022-05-18', 3),
    (1, 2, '2022-05-07', 1),
    (1, 1, '2022-03-24', 1),
    (1, 6, '2022-05-17', 5),
    (1, 7, '2022-05-25', 8),
    (2, 5, '2022-05-31', 3),
    (2, 7, '2022-01-21', 5),
    (2, 4, '2022-02-10', 7),
    (2, 1, '2022-05-30', 10),
    (2, 10, '2022-02-14', 2);

-- Create the products table
CREATE TABLE products (
    id INT AUTO_INCREMENT PRIMARY KEY,
    price DECIMAL(10, 2)
);

-- Insert data into the products table
INSERT INTO products (price)
VALUES
    (50.00),
    (15.00),
    (82.00),
    (78.00),
    (19.00),
    (199.00),
    (242.00),
    (104.00),
    (149.00),
    (163.00);


WITH MonthlyRevenue AS (
    SELECT
        DATE_FORMAT(o.order_date, '%Y-%m') AS order_year_month,
        o.product_id,
        ROUND(SUM(o.order_volume * p.price), 2) AS revenue
    FROM
        orders o
    JOIN
        products p ON o.product_id = p.id
    GROUP BY
        DATE_FORMAT(o.order_date, '%Y-%m'),
        o.product_id
),
RevenueWithMoMChange AS (
    SELECT
        mr.order_year_month,
        mr.product_id,
        mr.revenue,
        IFNULL(
            ROUND(
                (mr.revenue - LAG(mr.revenue) OVER (PARTITION BY mr.product_id ORDER BY mr.order_year_month)) / 
                LAG(mr.revenue) OVER (PARTITION BY mr.product_id ORDER BY mr.order_year_month), 2),
            0
        ) AS mom_change_in_revenue
    FROM
        MonthlyRevenue mr
)
SELECT
    rwm.order_year_month,
    rwm.product_id,
    rwm.revenue,
    rwm.mom_change_in_revenue
FROM
    RevenueWithMoMChange rwm
ORDER BY
    rwm.product_id DESC,
    rwm.order_year_month;

MySQL online editor

Write, Run & Share MySQL queries online using OneCompiler's MySQL online editor and compiler for free. It's one of the robust, feature-rich online editor and compiler for MySQL. Getting started with the OneCompiler's MySQL editor is really simple and pretty fast. The editor shows sample boilerplate code when you choose language as 'MySQL' and start writing queries to learn and test online without worrying about tedious process of installation.

About MySQL

MySQL is a open-source, free and very popular relational database management system which is developed, distributed and supported by Oracle corporation.

Key Features:

  • Open-source relational database management systems.
  • Reliable, very fast and easy to use database server.
  • Works on client-server model.
  • Highly Secure and Scalable
  • High Performance
  • High productivity as it uses stored procedures, triggers, views to write a highly productive code.
  • Supports large databases efficiently.
  • Supports many operating systems like Linux*,CentOS*, Solaris*,Ubuntu*,Windows*, MacOS*,FreeBSD* and others.

Syntax help

Commands

1. CREATE

CREATE TABLE table_name (
                column1 datatype,
                column2 datatype,
                ....);

Example

CREATE TABLE EMPLOYEE (
  empId INTEGER PRIMARY KEY,
  name TEXT NOT NULL,
  dept TEXT NOT NULL
);

2. ALTER

ALTER TABLE Table_name ADD column_name datatype;

Example

INSERT INTO EMPLOYEE VALUES (0001, 'Dave', 'Sales');

3. TRUNCATE

TRUNCATE table table_name;

4. DROP

DROP TABLE table_name;

5. RENAME

RENAME TABLE table_name1 to new_table_name1;

6. COMMENT

Single-Line Comments:

 --Line1;

Multi-Line comments:

   /* Line1,
   Line2 */

DML Commands

1. INSERT

INSERT INTO table_name (column1, column2, column3, ...) VALUES (value1, value2, value3, ...);

Note: Column names are optional.

Example

INSERT INTO EMPLOYEE VALUES (0001, 'Ava', 'Sales');

2. SELECT

SELECT column1, column2, ...
FROM table_name
[where condition];

Example

SELECT * FROM EMPLOYEE where dept ='sales';

3. UPDATE

UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition;

Example

UPDATE EMPLOYEE SET dept = 'Sales' WHERE empId='0001';

4. DELETE

DELETE FROM table_name where condition;

Example

DELETE from EMPLOYEE where empId='0001';

Indexes

1. CREATE INDEX

  CREATE INDEX index_name on table_name(column_name);
  • To Create Unique index:
  CREATE UNIQUE INDEX index_name on table_name(column_name);

2. DROP INDEX

DROP INDEX index_name ON table_name;

Views

1. Create a View

Creating a View:
CREATE VIEW View_name AS 
Query;

2. How to call view

SELECT * FROM View_name;

3. Altering a View

ALTER View View_name AS 
Query;

4. Deleting a View

DROP VIEW View_name;

Triggers

1. Create a Trigger

CREATE TRIGGER trigger_name trigger_time trigger_event
    ON tbl_name FOR EACH ROW [trigger_order] trigger_body
/* where
trigger_time: { BEFORE | AFTER }
trigger_event: { INSERT | UPDATE | DELETE }
trigger_order: { FOLLOWS | PRECEDES } */

2. Drop a Trigger

DROP TRIGGER [IF EXISTS] trigger_name;

Stored Procedures

1. Create a Stored Procedure

CREATE PROCEDURE sp_name(p1 datatype)
BEGIN
/*Stored procedure code*/
END;

2. How to call Stored procedure

CALL sp_name;

3. How to delete stored procedure

DROP PROCEDURE sp_name;

Joins

1. INNER JOIN

SELECT * FROM TABLE1 INNER JOIN TABLE2 where condition;

2. LEFT JOIN

SELECT * FROM TABLE1 LEFT JOIN TABLE2 ON condition;

3. RIGHT JOIN

SELECT * FROM TABLE1 RIGHT JOIN TABLE2 ON condition;

4. CROSS JOIN

SELECT select_list from TABLE1 CROSS JOIN TABLE2;