solution: Álvaro Sánchez

database.sql

@@ -0,0 +1,108 @@
+--  Sample employee database 
+--  See changelog table for details
+--  Copyright (C) 2007,2008, MySQL AB
+--  
+--  Original data created by Fusheng Wang and Carlo Zaniolo
+--  http://www.cs.aau.dk/TimeCenter/software.htm
+--  http://www.cs.aau.dk/TimeCenter/Data/employeeTemporalDataSet.zip
+-- 
+--  Current schema by Giuseppe Maxia 
+--  Data conversion from XML to relational by Patrick Crews
+-- 
+-- This work is licensed under the 
+-- Creative Commons Attribution-Share Alike 3.0 Unported License. 
+-- To view a copy of this license, visit 
+-- http://creativecommons.org/licenses/by-sa/3.0/ or send a letter to 
+-- Creative Commons, 171 Second Street, Suite 300, San Francisco, 
+-- California, 94105, USA.
+-- 
+--  DISCLAIMER
+--  To the best of our knowledge, this data is fabricated, and
+--  it does not correspond to real people. 
+--  Any similarity to existing people is purely coincidental.
+-- 
+
+DROP DATABASE IF EXISTS employees;
+CREATE DATABASE IF NOT EXISTS employees;
+USE employees;
+
+SELECT 'CREATING DATABASE STRUCTURE' as 'INFO';
+
+DROP TABLE IF EXISTS dept_emp,
+                     dept_manager,
+                     titles,
+                     salaries, 
+                     employees, 
+                     departments;
+
+/*!50503 set default_storage_engine = InnoDB */;
+/*!50503 select CONCAT('storage engine: ', @@default_storage_engine) as INFO */;
+
+CREATE TABLE employees (
+    emp_no      INT             NOT NULL,
+    birth_date  DATE            NOT NULL,
+    first_name  VARCHAR(14)     NOT NULL,
+    last_name   VARCHAR(16)     NOT NULL,
+    gender      ENUM ('M','F')  NOT NULL,    
+    hire_date   DATE            NOT NULL,
+    PRIMARY KEY (emp_no)
+);
+
+CREATE TABLE departments (
+    dept_no     CHAR(4)         NOT NULL,
+    dept_name   VARCHAR(40)     NOT NULL,
+    PRIMARY KEY (dept_no),
+    UNIQUE  KEY (dept_name)
+);
+
+CREATE TABLE dept_manager (
+   emp_no       INT             NOT NULL,
+   dept_no      CHAR(4)         NOT NULL,
+   from_date    DATE            NOT NULL,
+   to_date      DATE            NOT NULL,
+   FOREIGN KEY (emp_no)  REFERENCES employees (emp_no)    ON DELETE CASCADE,
+   FOREIGN KEY (dept_no) REFERENCES departments (dept_no) ON DELETE CASCADE,
+   PRIMARY KEY (emp_no,dept_no)
+); 
+
+CREATE TABLE dept_emp (
+    emp_no      INT             NOT NULL,
+    dept_no     CHAR(4)         NOT NULL,
+    from_date   DATE            NOT NULL,
+    to_date     DATE            NOT NULL,
+    FOREIGN KEY (emp_no)  REFERENCES employees   (emp_no)  ON DELETE CASCADE,
+    FOREIGN KEY (dept_no) REFERENCES departments (dept_no) ON DELETE CASCADE,
+    PRIMARY KEY (emp_no,dept_no)
+);
+
+CREATE TABLE titles (
+    emp_no      INT             NOT NULL,
+    title       VARCHAR(50)     NOT NULL,
+    from_date   DATE            NOT NULL,
+    to_date     DATE,
+    FOREIGN KEY (emp_no) REFERENCES employees (emp_no) ON DELETE CASCADE,
+    PRIMARY KEY (emp_no,title, from_date)
+) 
+; 
+
+CREATE TABLE salaries (
+    emp_no      INT             NOT NULL,
+    salary      INT             NOT NULL,
+    from_date   DATE            NOT NULL,
+    to_date     DATE            NOT NULL,
+    FOREIGN KEY (emp_no) REFERENCES employees (emp_no) ON DELETE CASCADE,
+    PRIMARY KEY (emp_no, from_date)
+) 
+; 
+
+CREATE OR REPLACE VIEW dept_emp_latest_date AS
+    SELECT emp_no, MAX(from_date) AS from_date, MAX(to_date) AS to_date
+    FROM dept_emp
+    GROUP BY emp_no;
+
+# shows only the current department for each employee
+CREATE OR REPLACE VIEW current_dept_emp AS
+    SELECT l.emp_no, dept_no, l.from_date, l.to_date
+    FROM dept_emp d
+        INNER JOIN dept_emp_latest_date l
+        ON d.emp_no=l.emp_no AND d.from_date=l.from_date AND l.to_date = d.to_date;