 -- Create a table called client with the following columns:
--      id- an auto-incrementing integer which is the primary key, size 11
--      first_name- a varchar with a maximum length of 255 characters, cannot be null
--      last_name- a varchar with a maximum length of 255 characters, cannot be null
--      email- a varchar with a maximum length of 255 characters, cannot be null
--      The combination of the first_nameand last_name must be unique in this table. Name this constraint as full_name
CREATE TABLE client (
    id INT(11) NOT NULL AUTO_INCREMENT,
    first_name VARCHAR(255) NOT NULL,
    last_name VARCHAR(255) NOT NULL,
    email VARCHAR(255) NOT NULL,
    CONSTRAINT full_name UNIQUE (first_name, last_name),
    PRIMARY KEY (id)
);


-- Create a table called employee with the following columns:
--      id- an auto-incrementing integer which is the primary key, size 11
--      first_name- a varchar of maximum length 255, cannot be null
--      last_name- a varchar of maximum length 255, cannot be null
--      start_date- a date, cannot be null
--      email- a varchar with a maximum length of 255 characters, cannot be null
--      The combination of the first_nameand last_name must be unique in this table. Name this constraint as full_name
CREATE TABLE employee (
    id INT(11) NOT NULL AUTO_INCREMENT,
    first_name VARCHAR(255) NOT NULL,
    last_name VARCHAR(255) NOT NULL,
    start_date DATE NOT NULL,
    email VARCHAR(255) NOT NULL,
    CONSTRAINT full_name UNIQUE (first_name, last_name),
    PRIMARY KEY (id)
);


-- Create a table called project with the following columns:
--      id- an auto-incrementing integer which is the primary key, size 11
--      title- a varchar of maximum length 255, cannot be null
--      comments- a text column
--      cid- an integer which is a foreign key reference to the client table
--      The project titlemust be unique in this table
CREATE TABLE project (
    id INT(11) NOT NULL AUTO_INCREMENT,
    title VARCHAR(255) NOT NULL UNIQUE,
    comments TEXT,
    cid INT NOT NULL,
    FOREIGN KEY (cid) REFERENCES client(id),
    PRIMARY KEY (id)
);


-- Create a table called works_on representing a many-to-many relationship between employees and projects, with the following properties:
--      pid- an integer which is a foreign key reference to the project table
--      eid- an integer which is a foreign key reference to the employee table
--      due_date- a date, not null
--      The primary key is a combination of eid and pid
CREATE TABLE works_on (
    pid INT NOT NULL,
    eid INT NOT NULL,
    due_date DATE NOT NULL,
    PRIMARY KEY (eid, pid),
    FOREIGN KEY (pid) REFERENCES project(id),
    FOREIGN KEY (eid) REFERENCES employee(id)
);

-- Insert the following into the client table:
--      First Name | Last Name | Email
--      Sara       | Smith     | [email protected]
--      Miguel     | Cabrera   | [email protected]
--      Bo         | Chan'g    | [email protected]
INSERT INTO client (first_name, last_name, email)
VALUES ("Sara", "Smith", "[email protected]"),
("Miguel", "Cabrera", "[email protected]"),
("Bo", "Chan'g", "[email protected]");

-- Insert the following into the employee table:
--      First name | Last Name | Start Date | Email
--      Ananya     | Jaiswal   | 2008-04-10 | [email protected]
--      Michael    | Fern      | 2015-07-19 | [email protected]
--      Abdul      | Rehman    | 2018-02-27 | [email protected]
INSERT INTO employee (first_name, last_name, start_date, email)
VALUES ("Ananya", "Jaiswal", "2008-04-10", "[email protected]"),
("Michael", "Fern", "2015-07-19", "[email protected]"),
("Abdul", "Rehman", "2018-02-27", "[email protected]");


-- Insert the following project instances into the project table 
-- (you should use a subquery to set up foreign key references AND not hard-coded numbers):
--      cid             | title                | comments
--      r to smiths     | Diamond              | Should be done by Jan 2019
--      r to bochang    | Chan'g               | Ongoing maintenance
--      r to mc         | The Robinson Project | NULL
INSERT INTO project (cid, title, comments)
VALUES ((SELECT id FROM client WHERE first_name = 'Sara' AND last_name = 'Smith'), 'Diamond', 'Should be done by Jan 2019'),
((SELECT id FROM client WHERE first_name = 'Bo' AND last_name = "Chan'g"), "Chan'g", 'Ongoing maintenance'),
((SELECT id FROM client WHERE first_name = 'Miguel' AND last_name = 'Cabrera'), 'The Robinson Project', NULL);



-- Insert the following into the works_on table. 
-- Again, your queries here should not have hard-coded integers for foreign keys.
--      eid             | pid                  | due_date
--      Ananya Jaiswal  | Chan'g               | 2020-11-19
--      Michael Fern    | The Robinson Project | 2020-12-05
--      Abdul Rehman    | Diamond              | 2021-01-01
INSERT INTO works_on (eid, pid, due_date)
VALUES ((SELECT id FROM employee WHERE first_name = 'Ananya' AND last_name = 'Jaiswal'), (SELECT id FROM project WHERE title = "Chan'g"), '2020-11-19'),
((SELECT id FROM employee WHERE first_name = 'Michael' AND last_name = 'Fern'), (SELECT id FROM project WHERE title = 'The Robinson Project'), '2020-12-05'),
((SELECT id FROM employee WHERE first_name = 'Abdul' AND last_name = 'Rehman'), (SELECT id FROM project WHERE title = 'Diamond'), '2021-01-01');

describe client;
describe employee;
describe project;
describe works_on;
SELECT * FROM works_on;
SELECT * FROM project;

created 1 year 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;