Friday 29 November 2019

MySQL employee database design example

In this article, we will share an employee database design example, which can be useful if you are looking for a Master-Detail database schema for educational or explanatory purposes.
The design of the database that we are going to share is the following:
Employee database design
Image 1. Employee database design
As you can see in the design, besides the employee table, the database will have other five tables: department, department_employee, department_manager, payment, and title.
The script to create the database is the following:

CREATE DATABASE IF NOT EXISTS `employees_database` DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;
USE `employees_database`;
CREATE TABLE `department` (
  `id` char(4NOT NULL,
  `name` varchar(40NOT NULL
ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `department` (`id``name`VALUES
('dep9''Customer Service'),
('dep5''Development'),
('dep2''Finance'),
('dep3''Human Resources'),
('dep1''Marketing'),
('dep4''Production'),
('dep6''Quality Management'),
('dep8''Research'),
('dep7''Sales');

CREATE TABLE `department_employee` (
  `emp_id` int(11NOT NULL,
  `dept_id` char(4NOT NULL,
  `from_date` date NOT NULL,
  `to_date` date NOT NULL
ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `department_employee` (`emp_id``dept_id``from_date``to_date`VALUES
(10001'dep5''1996-06-26''9999-01-01'),
(10002'dep7''2006-08-03''9999-01-01'),
(10003'dep4''2005-12-03''9999-01-01'),
(10004'dep4''1996-12-01''9999-01-01'),
(10005'dep3''1999-09-12''9999-01-01'),
(10006'dep5''2000-08-05''9999-01-01'),
(10007'dep8''1999-02-10''9999-01-01'),
(10008'dep5''2008-03-11''2018-07-31'),
(10009'dep6''2005-02-18''9999-01-01'),
(10010'dep4''2006-11-24''2010-06-26'),
(10010'dep6''2010-06-26''9999-01-01');

CREATE TABLE `department_manager` (
  `emp_id` int(11NOT NULL,
  `dept_id` char(4NOT NULL,
  `from_date` date NOT NULL,
  `to_date` date NOT NULL
ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `department_manager` (`emp_id``dept_id``from_date``to_date`VALUES
(10001'dep1''1995-01-01''2001-10-01'),
(10002'dep2''1995-01-01''1999-12-17'),
(10003'dep3''1995-01-01''2002-03-21'),
(10004'dep4''1995-01-01''1998-09-09'),
(10005'dep5''1995-01-01''2002-04-25'),
(10006'dep6''1995-01-01''1999-05-06');

CREATE TABLE `employee` (
  `id` int(11NOT NULL,
  `birth_date` date NOT NULL,
  `first_name` varchar(14NOT NULL,
  `last_name` varchar(16NOT NULL,
  `gender` enum('M','F'NOT NULL,
  `hire_date` date NOT NULL
ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `employee` (`id``birth_date``first_name``last_name``gender``hire_date`VALUES
(10001'1963-09-02''Dorris''Bodhi''M''1996-06-26'),
(10002'1974-06-02''Bryanna''Kolleen''F''1995-11-21'),
(10003'1969-12-03''Rayner''Colt''M''1996-08-28'),
(10004'1964-05-01''Tanner''Clifford''M''1996-12-01'),
(10005'1965-01-21''Trent''Dolph''M''1999-09-12'),
(10006'1963-04-20''Ashlee''Cristen''F''1999-06-02'),
(10007'1967-05-23''Irene''Yazmin''F''1999-02-10'),
(10008'1968-02-19''Terence''Dalton''M''2004-09-15'),
(10009'1962-04-19''Regina''Wayland''F''1995-02-18'),
(10010'1973-06-01''Shanon''Mortimer''F''1999-08-24');

CREATE TABLE `payment` (
  `emp_id` int(11NOT NULL,
  `salary` int(11NOT NULL,
  `from_date` date NOT NULL,
  `to_date` date NOT NULL
ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `payment` (`emp_id``salary``from_date``to_date`VALUES
(1000170117'1986-06-26''1987-06-26'),
(1000172102'1987-06-26''1988-06-25'),
(1000176074'1988-06-25''1989-06-25'),
(1000176596'1989-06-25''1990-06-25'),
(1000176961'1990-06-25''1991-06-25'),
(1000275828'1996-08-03''1997-08-03'),
(1000275909'1997-08-03''1998-08-03'),
(1000277534'1998-08-03''1999-08-03'),
(1000279366'1999-08-03''2000-08-02'),
(1000281963'2000-08-02''2001-08-02'),
(1000282527'2001-08-02''9999-01-01'),
(1000350006'1995-12-03''1996-12-02'),
(1000353616'1996-12-02''1997-12-02'),
(1000353466'1997-12-02''1998-12-02'),
(1000353636'1998-12-02''1999-12-02'),
(1000353478'1999-12-02''2000-12-01'),
(1000353699'2000-12-01''2001-12-01'),
(1000353311'2001-12-01''9999-01-01');

CREATE TABLE `title` (
  `emp_id` int(11NOT NULL,
  `title` varchar(50NOT NULL,
  `from_date` date NOT NULL,
  `to_date` date DEFAULT NULL
ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `title` (`emp_id``title``from_date``to_date`VALUES
(10001'Senior Engineer''1996-06-26''9999-01-01'),
(10002'Staff''2006-08-03''9999-01-01'),
(10003'Senior Engineer''2005-12-03''9999-01-01'),
(10004'Engineer''1996-12-01''2005-12-01'),
(10004'Senior Engineer''2005-12-01''9999-01-01'),
(10005'Senior Staff''2006-09-12''9999-01-01'),
(10005'Staff''1999-09-12''2006-09-12'),
(10006'Senior Engineer''2000-08-05''9999-01-01'),
(10007'Senior Staff''2006-02-11''9999-01-01'),
(10007'Staff''1999-02-10''2006-02-11'),
(10008'Assistant Engineer''2008-03-11''2010-07-31'),
(10009'Assistant Engineer''1995-02-18''2000-02-18'),
(10009'Engineer''2000-02-18''2005-02-18'),
(10009'Senior Engineer''2005-02-18''9999-01-01'),
(10010'Engineer''2006-11-24''9999-01-01');

ALTER TABLE `department`
  ADD PRIMARY KEY (`id`),
  ADD UNIQUE KEY `dept_name` (`name`);

ALTER TABLE `department_employee`
  ADD PRIMARY KEY (`emp_id`,`dept_id`),
  ADD KEY `dept_id` (`dept_id`);

ALTER TABLE `department_manager`
  ADD PRIMARY KEY (`emp_id`,`dept_id`),
  ADD KEY `dept_id` (`dept_id`);

ALTER TABLE `employee`
  ADD PRIMARY KEY (`id`);

ALTER TABLE `payment`
  ADD PRIMARY KEY (`emp_id`,`from_date`);

ALTER TABLE `title`
  ADD PRIMARY KEY (`emp_id`,`title`,`from_date`);


ALTER TABLE `department_employee`
  ADD CONSTRAINT `dept_emp_ibfk_1` FOREIGN KEY (`emp_id`REFERENCES `employee` (`id`ON DELETE CASCADE,
  ADD CONSTRAINT `dept_emp_ibfk_2` FOREIGN KEY (`dept_id`REFERENCES `department` (`id`ON DELETE CASCADE;

ALTER TABLE `department_manager`
  ADD CONSTRAINT `dept_manager_ibfk_1` FOREIGN KEY (`emp_id`REFERENCES `employee` (`id`ON DELETE CASCADE,
  ADD CONSTRAINT `dept_manager_ibfk_2` FOREIGN KEY (`dept_id`REFERENCES `department` (`id`ON DELETE CASCADE;

ALTER TABLE `payment`
  ADD CONSTRAINT `salaries_ibfk_1` FOREIGN KEY (`emp_id`REFERENCES `employee` (`id`ON DELETE CASCADE;

ALTER TABLE `title`
  ADD CONSTRAINT `titles_ibfk_1` FOREIGN KEY (`emp_id`REFERENCES `employee` (`id`ON DELETE CASCADE;

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