How to get from a select the result?

[Gabriel Espósito]

Hello.. I need to do something like:

item = db.getSchema().table("Employees");

employee = db.select(item.surname).

                   from(item).

                   where(item.name.eq(req['data']['Name'])). // req has the name

                   exec().then(function(rows){

                       return rows[0]['surname'];

                   });

                   console.log(employee); // I need the Surname of a given name outside the scope

But I get a Promise and I don't know how to extract the data... 

inside, very deep in the promise, there IS the correct data

Would you help me?

[Arthur Hsu]

Whenever you see a then() function, that means the object on its left-hand-side is likely a promise.

So it's perfectly reasonable employee is a promise (since query execution returns promise).

Lovefield's transaction execution returns promise and run asynchronously. A query execution started an implicit transaction.

[Gabriel Espósito]

Thanks Arthur. The fact is that I don't know how to extract data out of the scope of the "then()" from the promise... would you tell me how?

[Arthur Hsu]

That you need to accomodate Promise into your design. See https://developers.google.com/web/fundamentals/primers/promises/?hl=en to learn about how to use it.

[Gabriel Espósito]

Thanks Arthur for the information... I can not get the variable out the scope of the then... About the promise already can retrieve the info but can not out from the scope of the then()....

[dpa...@chromium.org]

I think that you are not fully understanding how Promises work. Your desire to "get the variable out of the scope" is invalid. Code inside a Promise callback is asynchronous (executes sometime later). You are asking how to get that information synchronously which is not possible. Try the following in your dev console

Promise.resolve().then(function() {console.log('executes later');});
console.log('executes first');

By the time the 2nd line executes, the Promise callback has not been executed yet. As previous comment suggests your design needs to accommodate asynchronous code.

[drdr...@gmail.com]

So annoying that people don't answer your question.

They know exactly what you mean but like to make it difficult.

I am also trying Lovefield but it's hard to learn.

Op maandag 30 mei 2016 05:22:33 UTC+2 schreef Gabriel Espósito: