 -- SELECT 'Hello', 'World';
-- outputs a table with 2 columns: 1 for each string

-- SELECT
-- SELECT by itself is invalid
-- highlighting parts of a SQL command will make that portion execute
  -- highlighted portions will execute, even if they're in comments
  
-- SELECT 'Hello' as FirstWord, 'World' as SecondWord;
-- this is an example of aliasing
-- FirstWord is the name of the 1st column
-- SecondWord is the name of the 2nd column

CREATE DATABASE Contacts;

CREATE TABLE address(	address_id INTEGER NOT NULL,	address_building_number VARCHAR(55) NOT NULL,	address_street VARCHAR(55) NOT NULL,	address_locality VARCHAR(55),	address_city VARCHAR(55) NOT NULL,	address_zip_postal VARCHAR(55) NOT NULL,	address_state_province_county VARCHAR(55) NOT NULL,	address_country VARCHAR(55) NOT NULL , CONSTRAINT PK_Address PRIMARY KEY (address_id) );
CREATE TABLE email_address(	email_address_id INTEGER NOT NULL,	email_address_person_id INTEGER,	email_address VARCHAR(55) NOT NULL, CONSTRAINT PK_email_address PRIMARY KEY (email_address_id ));
CREATE TABLE person(	person_id INTEGER  NOT NULL,  person_first_name VARCHAR(55) NOT NULL,	 person_last_name VARCHAR(55) NULL,	 person_contacted_number INTEGER NOT NULL, person_date_last_contacted DATETIME NOT NULL,person_date_added DATETIME NOT NULL,  CONSTRAINT PK_person PRIMARY KEY (person_id));
CREATE TABLE person_address(	person_address_id INTEGER NOT NULL,	person_address_person_id INTEGER NOT NULL,	person_address_address_id INTEGER NOT NULL, CONSTRAINT PK_person_address PRIMARY KEY (person_address_id));
CREATE TABLE phone_number(	phone_number_id INTEGER NOT NULL,	phone_number_person_id INTEGER NOT  NULL,	phone_number VARCHAR(55) NOT NULL, CONSTRAINT PK_phone_number PRIMARY KEY (phone_number_id));

INSERT INTO address (address_id, address_building_number, address_street, address_locality, address_city, address_zip_postal, address_state_province_county, address_country) VALUES (4, '555', 'Pluralsight', NULL, 'San Francisco', '91001', 'California', 'US');
INSERT INTO address (address_id, address_building_number, address_street, address_locality, address_city, address_zip_postal, address_state_province_county, address_country) VALUES (1, '555', 'Pluralsight', NULL, 'Los Angeles', '91001', 'California', 'US');
INSERT INTO address (address_id, address_building_number, address_street, address_locality, address_city, address_zip_postal, address_state_province_county, address_country) VALUES (2, '555', 'Trainsignal', NULL, 'Toronto', '7777', 'Ontario', 'Canada');
INSERT INTO address (address_id, address_building_number, address_street, address_locality, address_city, address_zip_postal, address_state_province_county, address_country) VALUES (3, '555', 'Pluralsight', 'Boonies', 'Somewhere', '11111', 'Maine', 'US');

INSERT INTO email_address (email_address_id, email_address_person_id, email_address) VALUES (1, 1, '[email protected]');
INSERT INTO email_address (email_address_id, email_address_person_id, email_address) VALUES (2, 1, '[email protected]');

INSERT INTO email_address (email_address_id, email_address_person_id, email_address) VALUES (4, 3, '[email protected]');
INSERT INTO email_address (email_address_id, email_address_person_id, email_address) VALUES (5, NULL, '[email protected]');

INSERT INTO person (person_id, person_first_name, person_last_name, person_contacted_number,person_date_last_contacted,person_date_added ) VALUES (1, 'Jon', 'Flanders', 5,'2013-09-14 11:43:31','2013-01-14 11:43:31');
INSERT INTO person (person_id, person_first_name, person_last_name, person_contacted_number,person_date_last_contacted,person_date_added) VALUES (2, 'Shannon', 'Ahern', 0,'2013-08-14 11:43:31','2013-02-14 11:43:31');
INSERT INTO person (person_id, person_first_name, person_last_name, person_contacted_number,person_date_last_contacted,person_date_added) VALUES (3, 'Fritz', 'Onion', 1,'2013-07-14 11:43:31','2013-03-14 11:43:31');
INSERT INTO person (person_id, person_first_name, person_last_name, person_contacted_number,person_date_last_contacted,person_date_added) VALUES (4, 'Jon', 'King', 4,'2013-06-14 11:43:31','2013-02-14 11:43:31');
-- even if two people have the same first name, they need different ids, in order for things to be valid


INSERT INTO person_address (person_address_id, person_address_person_id, person_address_address_id) VALUES (1, 1, 1);
INSERT INTO person_address (person_address_id, person_address_person_id, person_address_address_id) VALUES (3, 2, 1);
INSERT INTO person_address (person_address_id, person_address_person_id, person_address_address_id) VALUES (4, 2, 2);
INSERT INTO person_address (person_address_id, person_address_person_id, person_address_address_id) VALUES (5, 3, 3);


INSERT INTO phone_number (phone_number_id, phone_number_person_id, phone_number) VALUES (1, 1, '555-1212');
INSERT INTO phone_number (phone_number_id, phone_number_person_id, phone_number) VALUES (2, 2, '555-1213');
INSERT INTO phone_number (phone_number_id, phone_number_person_id, phone_number) VALUES (3, 3, '555-1214');
INSERT INTO phone_number (phone_number_id, phone_number_person_id, phone_number) VALUES (4, 3, '555-1215');

ALTER TABLE email_address  ADD  CONSTRAINT FK_email_address_person FOREIGN KEY(email_address_person_id)
REFERENCES person (person_id);
ALTER TABLE person_address  ADD  CONSTRAINT FK_person_address_address FOREIGN KEY(person_address_address_id)
REFERENCES address (address_id);
ALTER TABLE person_address  ADD  CONSTRAINT FK_person_address_person FOREIGN KEY(person_address_person_id)
REFERENCES person (person_id) ;
ALTER TABLE phone_number   ADD  CONSTRAINT FK_phone_number_person FOREIGN KEY(phone_number_person_id)
REFERENCES person (person_id);

USE Contacts;
-- SELECT p.person_first_name as FirstName FROM person p;
-- displays all first names, even duplicates

-- SELECT * from person;
-- display ALL table columns, not just first names

-- SELECT DISTINCT p.person_first_name as FirstName FROM person p;
-- doesn't display duplicated names

SELECT DISTINCT p.person_first_name, p.person_last_name as FirstName FROM person p;
-- displays all 4 sets of first and last names: since they're all different

created 3 years ago

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;