akko's questions

I have the following information in a MySQL table, what I need is to calculate the total by adding the result of multiplying the quantity by the corresponding price.

If it Precio con descuentois different from NULLit will be used to make the calculation.

| Cantidad   | Precio | Precio con descuento |
|------------|--------|----------------------|
| 1          | 10     | NULL                 |
| 2          | 10     | 5                    |
| 10         | 2      | 1                    |

1 * 10 = 10

2 * 5 = 10

10 * 1 = 10

TOTAL: 30

Currently I have:

SELECT cantidad, precio, precio_descuento FROM ventas WHERE cerrado = 1;

I need help to perform the following query in MySQL, I am joining two tables with a LEFT JOINto return results in case the second table does not contain information.

SELECT
  e.emp_id AS "empresa_id",
  et.idioma_id AS "idioma"
FROM empresa as e
LEFT JOIN empresa_translate as et
  on et.emp_id = e.emp_id
WHERE
  replace(replace(e.emp_nombre,'z','s'),'h','')
  LIKE replace(replace('%NOMBRE%','z','s'),'h','');

This gets the results regardless of whether the table empresa_translatehas any records associated with the id, however I need to implement the following logic to what I already have.

If there is a record in the table empresa_translateassociated with this id, it filters the results to show only those with a et.idioma_id = 1.

SELECT
  e.emp_id AS "empresa_id",
  et.idioma_id AS "idioma"
FROM empresa as e
LEFT JOIN empresa_translate as et
  on et.emp_id = e.emp_id
WHERE
  replace(replace(e.emp_nombre,'z','s'),'h','')
  LIKE replace(replace('%NOMBRE%','z','s'),'h','')
  AND et.idioma_id = 1;

The problem with doing it this way is that it doesn't return any results. What is the correct way to do this?

I need to query a table productowhere there is a property called nombreto search for a similar name LIKE.

SELECT *
FROM producto
WHERE nombre LIKE '%Dulces%'

But now I need this to make the use of the Sand of indifferent Z, that is, if they search Dulcezfor the results of the word to appear Dulcesand also the results of Dulcez. Likewise, if they search for the word Dulces, the results of Dulcesand should appear Dulcez.

For the same problem, I have to ignore the use of the leta H, that is, if they search, Aorathe results of Ahora.

This happens, I have two main branches: master and development.

So far master had one commit (the one at the beginning of the project) and my development branch had several commits.

My flow is this: I create a branch every time I am going to make a change and when I finish I do a merge to development

$ git checkout desarrollo && git merge rama-de-cambio

Accidentally merged into master using

$ git checkout master && git merge rama-de-cambio

What is the way to return master to its original state and be able to merge it to my development branch?

I have the following problem, I have an express project that uses the package mssqlto connect to a SQL Server database. To make the connection I have to specify the data in an object.

produccion = {
  user: 'xxx',
  password: 'xxx',
  server: 'nombre\\nombre',
  database: 'xxx'
};

In the case of servercontains a \\. Although I really don't know why.

I am developing the project on the local network with a Windows machine, I have no problem connecting to the server. Now when I pass it to a Debian server that is also on the local network the connection cannot be established.

I have tried to replace the nombre\\nombrewith the ip, but it doesn't work either on my windows machine or on the debian server.

This is the error it sends me:

{ ConnectionError: Failed to lookup instance on miServidor - getaddrinfo ENOTFOUND miServidor    at Connection.tedious.once.err (/var/www/html/node_modules/mssql/lib/tedious.js:239:17)    at Object.onceWrapper (events.js:273:13)    at Connection.emit (events.js:182:13)    at /var/www/html/node_modules/tedious/lib/connection.js:848:20    at /var/www/html/node_modules/tedious/lib/instance-lookup.js:83:15    at GetAddrInfoReqWrap.callback (/var/www/html/node_modules/tedious/lib/sender.js:58:18)    at GetAddrInfoReqWrap.onlookupall [as oncomplete] (dns.js:70:17)  code: 'EINSTLOOKUP',  originalError:   { ConnectionError: Failed to lookup instance on miServidor - getaddrinfo ENOTFOUND miServidor       at ConnectionError (/var/www/html/node_modules/tedious/lib/errors.js:12:12)       at /var/www/html/node_modules/tedious/lib/connection.js:848:36       at /var/www/html/node_modules/tedious/lib/instance-lookup.js:83:15       at GetAddrInfoReqWrap.callback (/var/www/html/node_modules/tedious/lib/sender.js:58:18)       at GetAddrInfoReqWrap.onlookupall [as oncomplete] (dns.js:70:17)     message:      'Failed to lookup instance on miServidor - getaddrinfo ENOTFOUND miServidor',
     code: 'EINSTLOOKUP' },
  name: 'ConnectionError' }

The documentation mssqlis not very clear about the EINSTLOOKUP.

EINSTLOOKUP (ConnectionError) - Instance lookup failed.

I'm making a program in go and I'd like to upload it to Github under the GPL license, but I'm using someone else's package which is licensed under MIT. I can do this?

Assuming I have an array of JSON that looks like this:

[
  {
    'nombre': 'X',
    'asistio': true
  },
  {
    'nombre': 'X',
    'asistio': false
  },
  {
    'nombre': 'X',
    'asistio': true
  },
  {
    'nombre': 'X',
    'asistio': true
  }
]

How could I count elements whose key asistio === true?

Assuming I have a text file called prueba.txt.

Hola

And I encrypt it with GPG as follows:

$ gpg -c prueba.txt

This asks me for a password and then generates the prueba.txt.gpg. Now if you wanted to decrypt the file you would have to do the following:

$ gpg --decrypt prueba.txt.gpg

Which should ask me for the password of the file so it can decrypt it, but it doesn't. It just decrypts it without any password.

Assuming I have two copies of the same object exactly the same and one with some difference:

let uno  = {"nombre": "Daniela", "edad": 24};
let dos  = {"nombre": "Daniela", "edad": 24};
let tres = {"nombre": "Daniela", "edad": 25};

If I compare them as follows, they all give me false:

console.log(a == b); // False
console.log(a === b); // False
console.log(a == c); // False
console.log(a === c); // False

But I would like to know how to compare them so that when comparing the object awith the object bI get a true.

Assuming I have a string variable with the text string of a hexadecimal number, how can I save it to a number?

string n = "0X54";
int a = int(n);
int b = static_cast<int>(n);

It throws me the error:invalid cast from type ‘std::__cxx11::string {aka std::__cxx11::basic_string<char>}’ to type ‘int’

I have a set of elements <a>that have, for example:

<a class="menu-elemento" href="#">Hola</a>
<a class="menu-elemento" href="#">Mundo</a>

And I want to add text to the existing one. So that they are like this:

<a class="menu-elemento" href="#">*** Hola</a>
<a class="menu-elemento" href="#">*** Mundo</a>

Where ***they represent the text I want to insert. How can I achieve this using jquery or native javascript?

I need to install the mbregex module. I currently have php7. Do you know which package I should install?

If I opened a connection to insert data into a database with

$conn = new mysqli($HOST, $USUARIO, $PASSWORD, $DB);

What is the correct way to close the connection at the end of my script?

I have the following lines in my vimrc which work perfectly on Linux, but don't work on OS X or Windows.

set relativenumber
nmap <F5> :set relativenumber! number!<CR>
imap <F5> <ESC>:set relativenumber! number!<CR>

The idea is that pressing F5 will toggle between relative and absolute, but the toggle only works the first time.

I need to remove jpg files from within a directory tree, but I only need to remove files that are less than n days old. Eg Delete jpg images that are 3 days or less from being created.

This is what I have so far but it doesn't work:

$ find ~/la/ruta -name *.jpg -mtime -2 -exec rm {} \;
zsh: no matches found: *.jpg

$ find la/ruta/*.jpg -mtime -2 -exec rm {} \; 
zsh: no matches found: la/ruta/*.jpg

I have a function that pauses the console for a few seconds and then continues to the next function:

void esperar(double segundos){
    if(segundos < 0) return;
    #ifdef _WIN32
        segundos *= 1000;
        int goal = (int) segundos + clock();
        while(goal > clock());
    #else
        segundos *= 1000000;
        int goal = (int) segundos;
        usleep(goal);
    #endif
}

Assuming I want to print the numbers 1 to 10 with a for loop I get two different answers depending on whether there is a line break or not.

for(int i = 0; i < 10; ++i){
    cout << i + 1 << " ";
    esperar(0.1);
}

In the first loop I leave a space after each number, but this loop waits a tenth of a second (0.1 * 1000000) for each cout in the loop, for a total of 1 second. Only until the 10 cycles of 0.1 seconds are finished is the string printed.

1 2 3 4 5 6 7 8 9 10

In the second loop I leave a line break between each number.

for(int i = 0; i < 10; ++i){
    cout << i + 1 << endl;
    esperar(0.1);
}

But this has a different (and desired) behavior. After printing the first cout the console waits 0.1 seconds to print the second cout, waits 0.1 seconds and prints the next one....

1
//0.1 segundos
2
//0.1 segundos
3
//0.1 segundos
4
//0.1 segundos
5
//0.1 segundos
[...]

I have the following libraries included

#include<time.h>
#include<unistd.h>

Is there a way to correct this?

I would like to change the colors of the ls command on my data partition, since the directories are hard to read from the console.

It's an NTFS partition that I share with Windows and my /etc/fstab file contains the following for the partition:

/dev/sda4 /media/datos ntfs-3g rw,defaults 0 0

I need to change the content attribute of the after and before pseudo elements of the next HTML element without using libraries like jQuery . If I did something similar with CSS it would be something like this:

#text::before{background:red;display:block,content:"HolaMundo";}
#text::after{background:blue;color:red,font-size:100px;}

What would be the way to do it with Javascript?

var text = document.getElementById("text");
text...

I have a small binary tree program spread over 4 files: main.cpp, tree.h, loop.h and node.h.

Inside the main.cpp file I include loop.h, inside loop.h I include arbol.h and inside arbol.h I include node.h

I just created a small function inside the Loop class of my loop.h file, which is a simple copy of the Sleep function from the windows.h library. I want to use this function within a member function of the Tree class that prints the nodes of the tree on the screen, that is, I want that every time a node is printed on the screen there is a wait of x seconds.

My error arises when I want to create a Loop class object within the Tree class or when I want to use inheritance, the compiler generates the error "Loop does not mean a type". So far I have tried simple inheritance, friend classes and friend methods. I also removed the function from the loop class and declared it inside the Tree class to test its correct operation.

I do not include details of the node.h file as it is just a class with the Node structure.

loop.h file

#ifndef LOOP_H
#define LOOP_H

#include<iostream>
using namespace std;
#include "arbol.h"
#include<time.h>

class Loop{
private:
    Arbol Kyou;   /* 
                      Se crea un bojeto derivado de la clase Árbol,
                      este objeto lo utilizo para ejecutar las funciones
                      de la clase Arbol (como lo es crear un nuevo
                      nodo, buscar nodo, etc) dentro de mis funciones de
                      la clase Loop (como lo es pedir los datos del nodo,
                      etc)
                      E.g. void pedirDatos(){
                                cout << "Dame numero: ";
                                cin >> n;
                                Kyou.CrearNodo(n);
                           }
                  */
public:
    void esperar(float segundos){...}
    /* Más funciones que no son importantes para el problema */
};

#endif

File tree.h

#ifndef ARBOL_H
#define ARBOL_H

#include "nodo.h"
#include "loop.h" /* Incluyo el archivo loop.h */

class Arbol{
    private:
        Nodo* Raiz;
        int contador = 0;
        Loop mano; /* El error es este */
    public:
        void MostrarArbol(){
            mano.esperar(0.5); /* La función es de la clase Loop */
            /* El proceso recursivo para mostrar el árbol */
        }
};

#endif

The main.cpp file

#include<iostream>
using namespace std;
#include "loop.h"
int main(){
    Loop l;
    l.loop(); /* Función miembro de la clase Loop que genera todo el programa */
    return 0;
}

What I want is to be able to override the functions of the sum class and replace them with the functions of the loop class. This has to do with Polymorphism.

In this code I explain better the question (see the comment):

#include<iostream>
using namespace std;

class suma{
    public:
        void leer(int &a, int &b, int &c);
        void calculo(int &a, int &b, int &c);
        void escribir(int &a, int &b, int &c);
};
class loop: public suma{
    public:
        void leer(int &a, int &b, int &c);
        void calculo(int &a, int &b, int &c);
        void escribir(int &a, int &b, int &c);
};

main(){
    int a, b, c;

    suma s;
    loop l;



    // Anulación <---- 
    cout << "Se supone que con esto anulo." << endl;
    s = l; // <---- Se supone que así anulo las funciones del objeto s
           //       y le asigno las funciones del objeto l
    s.leer(a, b, c);
    s.calculo(a, b, c);
    s.escribir(a, b, c);
}

void suma::leer(int &a, int &b, int &c){
    cout << "SUMA" << endl;
    cout << "Ingresa numero a: ";
    cin >> a;
    cout << "Ingresa numero b: ";
    cin >> b;
}
void suma::calculo(int &a, int &b, int &c){
    c = a + b;
}
void suma::escribir(int &a, int &b, int &c){
    cout << a << " + " << b << " = " << c << endl;
}

void loop::leer(int &a, int &b, int &c){
    cout << "LOOP" << endl;
    cout << "Ingresa numero a: ";
    cin >> a;
    cout << "Ingresa numero b: ";
    cin >> b;
}
void loop::calculo(int &a, int &b, int &c){
    c = a * b;
}

void loop::escribir(int &a, int &b, int &c){
    cout << a << " * " << b << " = " << c << endl;
}