Sequelize insert into join table (many-to-many)

2019+

After Sequelize 5+, findById() is replaced by findByPk()

Ledger.findByPk(22).then(ledger=>{
    ledger.setCoins([1,2]).then(sc=>{
        console.log(sc);
    });
});

Well, I solved the problem with setCoins, above. Apparently it takes id numbers and not objects, so this works:

Ledger.findById(22).then(ledger=>{
    ledger.setCoins([1,2]).then(sc=>{
        console.log(sc);
    });
});

I'd still like to understand includes and associations better, though.