Pablo Lozano's questions

I am grouping records (tasks) that have an identifier code.

The code is unique, but there are tasks that are a continuation of others and this is reflected in its code. For example:

• 12345: Original record
• 12345A: New version of register 12345
• 12345B: Another version of register 12345
• 12345C: Third version of register 12345

And here comes my problem:

• 12345CONT: Continuation (of the active version) of 12345 (it does not matter if the active one is the original or A, B or C)
• 12345CONT2: Second continuation of 12345
• 12345PF: Final Information
• ... (other endings, always more than one letter

I want to capture the following groups:

ID - Versión (A,B,C,D -opcional-) - Tipo de tarea (CONT<n>, PF<n>, ...)

My regex is currently the following:

(\d+)[ABCD]?(CONT\d?|PF\d?|REV|REP)?

But it has the problem that 12345CONTit captures 12345 - Cme and discards the ONT. I'm looking at "look-ahead" options, but I haven't quite found the solution.

How to capture CONT and C separately?

I have a project in a git repository with the code of an application ( App1 onwards).

I have been asked to create a second very similar application. In fact, it's almost a second instance of App1, so I've done the obvious: create a fork of the repository and start modifying what's going to be different. So far no problems.

What I don't know how to solve is the tag issue: every time I deploy a new version, using semver , I create a tag: v1.0.0, v1.1.0, v2.0.0...etc. The problem is that in the new project I wanted to name the first production deployment App2 v1.0.0, but the tag v1.0.0 (and a couple of dozen others) is already used.

Can I easily delete all the tags on my fork? Can it have any unexpected consequences?

If I have a form and I assign a function to the submit event like so:

$('#miForm').on('submit',hazAlgo);

function hazAlgo(evento) {
  console.log('Me han pulsado');
  // ... 
  return false; //evito el submit
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

<form id="miForm" action="#">

  <button>Púlsame</button>
</form>

I have seen that there are several ways to prevent the submit from happening:

1. Let the doSomething function return false.
2. Let the doSomething function call evento.preventDefault().
3. Let the doSomething function call evento.stopImmediatePropagation().

What are the differences between these three? o When should each be called?

When we program with Typescript, we have a concept that doesn't exist in Javascript: interfaces. In ES6 there are classes, which are syntactic sugar for classical prototyping, but no variable typing and nothing resembling an interface.

One may think that interfaces are the same as in Java or C#, but I have come across this:

class MiClase {

  constructor( public atributoA: string) {}

  metodoA() {
    //hace algo
  }
}

interface MiInterfaz extends MiClase {
    algo: any;
}

function miFuncion(attr: MiClase) {
  console.log(attr instanceof MiClase);
}

function miFuncion2(attr: MiInterfaz) {
  console.log(attr instanceof MiClase);
}

let a = {
    atributoA: 'hola',
    atributoB: 6,
    metodoA: function () { },
};


miFuncion(a); //false
miFuncion2(a);//false

let b = new MiClase('Una auténtica instancia de MiClase');

miFuncion(b); //true
miFuncion2(b);//compilador marca error, no cumple la interfaz

What's going on here?

• Why does ait not give an error miFuncionwhen it is clearly not of the class MiClase?
• Why are they interchangeable? The interface extends a class and doesn't give an error!

The following code fails:

let obj1,obj2;
obj2 = {
  atributo: 'texto'
};

console.log(obj1.atributo);

Showing in console the message:

Uncaught TypeError: Cannot read properties of undefined (reading 'attribute')

In Firefox (v96) the message is:

Uncaught TypeError: obj1 is undefined

What does it mean and how can I fix it?

The terms JSON and object (and even JSON object ) are often used interchangeably when talking about a data structure, especially in AJAX-related contexts.

• What is the difference between both?
• Is a JSON a Javascript object or is it something else?

I have to obtain a list of the company's clients to whom we have invoiced something during the current year, indicating how much we have invoiced each month.

I have two tables: the customer table (customer) and the invoice table (invoice). The relationship is obvious: a customer can have many invoices, and each invoice is related to a single customer.

The only thing that came to my mind is the following:

select id, 
name as "Nombre",
identity_number as "CIF", 
(select sum(total) 
    from invoice 
    where payment_date between '2017-01-01' and '2017-02-01' and customer_id=c.id group by customer_id) as "Enero",
(select sum(total) 
    from invoice 
    where payment_date between '2017-02-01' and '2017-03-01' and customer_id=c.id group by customer_id) as "Febrero",
(select sum(total) 
    from invoice 
    where payment_date between '2017-03-01' and '2017-04-01' and customer_id=c.id group by customer_id) as "Marzo",
(select sum(total) 
    from invoice 
    where payment_date between '2017-04-01' and '2017-05-01' and customer_id=c.id group by customer_id) as "Abril",
(select sum(total) 
    from invoice 
    where payment_date between '2017-05-01' and '2017-06-01' and customer_id=c.id group by customer_id) as "Mayo",
(select sum(total) 
    from invoice 
    where payment_date between '2017-06-01' and '2017-07-01' and customer_id=c.id group by customer_id) as "Junio",
(select sum(total) 
    from invoice 
    where payment_date between '2017-07-01' and '2017-08-01' and customer_id=c.id group by customer_id) as "Julio",
(select sum(total) 
    from invoice 
    where payment_date between '2017-08-01' and '2017-09-01' and customer_id=c.id group by customer_id) as "Agosto",
(select sum(total) 
    from invoice 
    where payment_date between '2017-09-01' and '2017-10-01' and customer_id=c.id group by customer_id) as "Septiembre",
(select sum(total) 
    from invoice 
    where payment_date between '2017-10-01' and '2017-11-01' and customer_id=c.id group by customer_id) as "Octubre",
(select sum(total) 
    from invoice 
    where payment_date between '2017-11-01' and '2017-12-01' and customer_id=c.id group by customer_id) as "Noviembre",
(select sum(total) 
    from invoice 
    where payment_date between '2017-12-01' and '2017-12-31' and customer_id=c.id group by customer_id) as "Diciembre"
from customer c
where c.branding_id=1 and (select sum(total) 
    from invoice 
    where payment_date between '2017-01-01' and '2017-12-31' and customer_id=c.id group by customer_id) > 0

This works, but I find it extremely inefficient (there are 13 subqueries, if we include the one in the WHERE). Is there any way to simplify this query or is it the best way to get the data?