I am trying to create a bot for the discord platform that will search a SQL database and return the objects to the chat for people to see.

SQL uses promises and I have been unable to successfully turn the promise it is returning me into something I can return to the chat (a string or array).

This code queries the database:

function spell(name) {
var spellData = sql.get("SELECT * FROM spells WHERE LOWER(name) = '"+ name.toLowerCase() + "'");
spellData.then( value => {
    console.log(spellData)
    return spellData;
  });

}

The table:

CREATE TABLE spells (
    `name` VARCHAR(25),
    `casting_time` VARCHAR(95),
    `ponents` VARCHAR(215),
    `description` VARCHAR(3307),
    `duration` VARCHAR(52),
    `level` INT,
    `range` VARCHAR(28),
    `school` VARCHAR(13)
  );

I'm using node.js, sqlite, and discord.js.

I am trying to create a bot for the discord platform that will search a SQL database and return the objects to the chat for people to see.

SQL uses promises and I have been unable to successfully turn the promise it is returning me into something I can return to the chat (a string or array).

This code queries the database:

function spell(name) {
var spellData = sql.get("SELECT * FROM spells WHERE LOWER(name) = '"+ name.toLowerCase() + "'");
spellData.then( value => {
    console.log(spellData)
    return spellData;
  });

}

The table:

CREATE TABLE spells (
    `name` VARCHAR(25),
    `casting_time` VARCHAR(95),
    `ponents` VARCHAR(215),
    `description` VARCHAR(3307),
    `duration` VARCHAR(52),
    `level` INT,
    `range` VARCHAR(28),
    `school` VARCHAR(13)
  );

I'm using node.js, sqlite, and discord.js.

• javascript
• node.js
• sqlite
• promise
• discord.js

• For a start, use the value (the argument of .then), not the Promise itself – CertainPerformance Commented Aug 15, 2018 at 1:12
• if you do that, @CertainPerformance - that would imply - spellData.then( value => { return value; }); - which is redundant ... and still, spell won't return a thing – Jaromanda X Commented Aug 15, 2018 at 1:15

2 Answers 2

If you want to return the Promise object to the caller, simply do:

function spell(name) {
    return sql.get("SELECT * FROM spells WHERE LOWER(name) = '" + name.toLowerCase() + "'")
}

Then, in your client:

spell('some_name').then(function(result) { console.log(result); })

Or, if you're into awaiting:

let results = await spell('some_name')
console.log(results)

Don't know if you're making use of it or not but "parameterized queries" will guard against SQL injection attacks. Your NPM package of choice should have an adequately managed implementation.

It seems like you may be misunderstanding how promises work. Even after a promise resolves, it's still a promise object. So in your then callback, when you call console.log(spellData) you're just logging the promise object. The data you want is actually passed into the callback as value, so the working code would be

function spell(name) {
var spellData = sql.get("SELECT * FROM spells WHERE LOWER(name) = '"+ name.toLowerCase() + "'");
return spellData.then( value => {
    console.log(value) //log the returned value
    return value; // returning the value from a then function returns a new promise, so the spell function also returns a promise which you can handle similarly 
  });

}