SQL Queries: Examples and Explanations

Here are some SQL query examples to help you perform common database tasks:

Selecting Data

  1. Display jobs with a minimum salary greater than 10000

    SELECT * FROM JOBS WHERE MIN_SALARY > 10000

  2. Display the first name and hire date of employees who joined between 2002 and 2005

    SELECT FIRST_NAME, HIRE_DATE FROM EMPLOYEES WHERE TO_CHAR(HIRE_DATE, 'YYYY') BETWEEN 2002 AND 2005 ORDER BY HIRE_DATE

  3. Display the first name and hire date of employees who are either IT Programmers or Sales Managers

    SELECT FIRST_NAME,

Read More

Pascal Program: Math & Geometry Calculations Menu

PROGRAM MenuFunctionsOrProcedures;

USES crt;

VAR
  B, X, R, Y: INTEGER;

Functions

FUNCTION Sum (N: INTEGER): INTEGER; VAR I, S: INTEGER; BEGIN S := 0; FOR I := 1 TO N DO BEGIN S := S + I; END; Sum := S; END;FUNCTION Factorial (N: INTEGER): INTEGER; VAR I, F: INTEGER; BEGIN F := 1; IF N >= 0 THEN BEGIN FOR I := 1 TO N DO BEGIN F := F * I; END; END ELSE BEGIN F := 0; // Factorial is not defined for negative numbers END; Factorial := F; END;FUNCTION Power (Base, Exponent: INTEGER): INTEGER; VAR Read More

Book Acknowledgements: Contributors and Image Sources

Acknowledgements

Contributors and Collaborators

The authors would like to thank everyone who has helped in the creation of this book:

  • José Vicente Gargallo (Computing Engineer)
  • Xavier Amorós (Telecommunications Engineer)
  • Vicente Puchol (Agricultural Engineer and employee at Isagri)
  • Daniel de las Heras (Graphic Designer)
  • Ted McAleer (Voiceover Actor)
  • Andy Boyns (Voiceover Actor)
  • Jenn Henry (Voiceover Actress)

Image and Icon Sources

We would like to thank the following websites for the permission to reproduce

Read More

Trigonometry: Functions, Laws, and Applications

Trigonometric Functions

Even Functions: cos(-t) = cos(t), sec(-t) = sec(t)

Odd Functions: sin(-t) = -sin(t), tan(-t) = -tan(t), csc(-t) = -csc(t), cot(-t) = -cot(t)

Example: A point P(x, y) is shown on the unit circle corresponding to a real number t. Find the values of the trigonometric functions at t.

A) P(-15/17, 8/17):

  • sin(t) = 8/17
  • cos(t) = -15/17
  • tan(t) = -8/15
  • csc(t) = 17/8
  • sec(t) = -17/15
  • cot(t) = -15/8

Graphs of Trigonometric Functions

Amplitude, Period, and Phase Shift:

y = Asin(Bx):

  • |A|: Amplitude
Read More

RMI Elevator System: Server-Side Code Analysis

AscensorRMI: Server Package

This section details the AscensorRMI class, which extends UnicastRemoteObject and represents a remote elevator object.


package server;
import java.rmi.*;
import java.rmi.server.UnicastRemoteObject;
import interfaz.GestorAscensores;

public class AscensorRMI extends UnicastRemoteObject {
    private static final long serialVersionUID = 1L;
    Gate door;
    private int floor;
    private int state;
    private int id;
    int model;

    public AscensorRMI(int num) throws 
Read More

Network Device Configuration: Comprehensive Command Reference

Network Device Configuration Commands

This document provides a comprehensive reference to configuration commands for network devices.

  • aaa: Authentication, Authorization and Accounting.
  • access-list: Add an access list entry.
  • alias: Create command alias.
  • arp: Set a static ARP entry.
  • banner: Define a login banner.
  • boot: Boot Commands.
  • buffers: Adjust system buffer pool parameters.
  • cdp: Global CDP configuration subcommands.
  • clock: Configure time-of-day clock.
  • cluster: Cluster configuration commands.
  • cns: CNS Subsystem.
Read More