.sum on an empty matching set results in NaN

What you are doing?

I’m trying to use the SUM aggregate on an empty matching set

//imagine we have Payments table empty yet
Payment.sum('amount').then(console.log)
//logs NaN

What do you expect to happen?

I’d like the value in this case to be 0 since by definition, a sum is a number, not a NaN.

Why this happens?

I’ve quickly found that this happens due to this:

//node_modules/sequelize/lib/query-interface.js:702
//result contains null as we don't have any matching records
result = parseFloat(result);

What could be done?

since the dataType requested is dataType instanceof DataTypes.DECIMAL || dataType instanceof DataTypes.FLOAT as stated in node_modules/sequelize/lib/query-interface.js:701, we can additionally check whether the result variable contains null and in this case return 0. I can submit a PR with this fix easily though I’d first like to ensure that I’m not the only one expecting 0 in this case rather than NaN.

__Dialect: postgres __Database version: 9.5.3 __Sequelize version: 3.19.3

[bminer]

This is silly IMHO. sum should return null or 0. Not NaN.

[janudewangga]

Is it fixed yet? I just had a same problem in 4.36.1