CREATE TABLE category (
    category_id INT PRIMARY KEY,
    category_name VARCHAR(50)
);

CREATE TABLE product (
    product_id INT PRIMARY KEY,
    product_name VARCHAR(100),
    category_id INT,
    price DECIMAL(10, 2),
    FOREIGN KEY (category_id) REFERENCES category (category_id)
);

CREATE TABLE address (
    address_id INT PRIMARY KEY,
    city VARCHAR(50),
    country VARCHAR(50)
);

CREATE TABLE customer (
    customer_id INT PRIMARY KEY,
    customer_name VARCHAR(100),
    address_id INT,
    FOREIGN KEY (address_id) REFERENCES address (address_id)
);


CREATE TABLE date_dimension (
    date_id INT PRIMARY KEY,
    date_value DATE,
    day_of_week VARCHAR(10),
    month VARCHAR(10),
    year INT
);

CREATE TABLE sales (
    sales_id INT PRIMARY KEY,
    date_id INT,
    product_id INT,
    customer_id INT,
    quantity INT,
    total_amount DECIMAL(10, 2),
    FOREIGN KEY (date_id) REFERENCES date_dimension (date_id),
    FOREIGN KEY (product_id) REFERENCES product (product_id),
    FOREIGN KEY (customer_id) REFERENCES customer (customer_id)
);


INSERT INTO category (category_id, category_name)
VALUES
    (1, 'Electronics'),
    (2, 'Home & Kitchen'),
    (3, 'Clothing')
    ;

INSERT INTO address (address_id, city, country)
VALUES
    (1, 'New York', 'USA'),
    (2, 'London', 'UK'),
    (3, 'Sydney', 'Australia')
    ;

INSERT INTO product (product_id, product_name, category_id, price)
VALUES
    (1, 'Product A', 1, 499.99),
    (2, 'Product B', 2, 89.99),
    (3, 'Product C', 3, 29.99)
    ;

INSERT INTO customer (customer_id, customer_name, address_id)
VALUES
    (101, 'John Doe', 1),
    (102, 'Jane Smith', 2),
    (103, 'Michael Johnson', 3)
    ;
    
INSERT INTO date_dimension (date_id, date_value, day_of_week, month, year)
VALUES
    (1, '2023-08-01', 'Tuesday', 'August', 2023),
    (2, '2023-08-02', 'Wednesday', 'August', 2023),
    (3, '2023-08-03', 'Thursday', 'August', 2023)
    ;

INSERT INTO sales (sales_id, date_id, product_id, customer_id, quantity, total_amount)
VALUES
    (1001, 1, 1, 101, 2, 999.98),
    (1002, 2, 2, 102, 1, 89.99),
    (1003, 3, 3, 103, 5, 149.95)
    ;

    
SELECT * FROM product;
SELECT * FROM sales;
SELECT * FROM customer;
SELECT * FROM category;
SELECT * FROM address;
SELECT * FROM date_dimension;

MySQL online editor

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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;