Express application cannot get certain item from my database (Sqlite) - node.js

Question

I am creating an application in which users can create posts and comment on these. Creating, updating and deleting posts works as intended, and so does creating comments.
When the user creates a comment, its accountId is passed to the database.
When deleting a specific comment, the accountId is passed to verify that the user is allowed to delete it.
The problem is, it seems like the accountId isn't fetched from the database, though the query asks for all details from the database table called "comments".
The app is divided into two files, db.js, and app.js.
I have tried modifying the request. In order to troubleshoot, I added a line of code checking if the comment.accountId was fetched, but that is where I get the error.
/* in db.js: */
//get comment by comment id
exports.getCommentById = (id, callback) => {
const query = 'SELECT * FROM comments WHERE id = ?'
const values = [ id ]
db.all(query, values, (error, comment) => {
if (error) {
console.log(error)
callback(['databaseError'])
return
} else if (!comment) {
console.log(error)
callback(['notFound'])
return
} else {
callback([], comment)
}
})
}
/* in app.js */
app.delete('/comments/:commentId', (req, res, next) => {
const commentId = req.params.commentId
db.getCommentById(commentId, (errors, comment) => {
if (errors.length > 0) {
res.status(500).json({
message: 'serverError'
}).end()
return
} else if (!comment) {
res.status(404).json({
message: 'notFound'
}).end()
return
}
const accountId = req.accountId //from my auth middleware
const commAccId = comment.accountId
if(!commAccId) {
console.log(accountId)
console.log(commAccId)
res.status(404).json({
message: 'AccIdNotFound'
}).end()
return
}
- - - - - ^ this is the error checking I inserted, and this is where the error is thrown, so it seems like the id is just not found.
if(!accountId) {
res.status(401).json({
message: 'notAuthenticated'
}).end()
return
} else if (comment.accountId != accountId) {
res.status(401).json({
message: 'notAuthorized'
}).end()
return
}
//plus code for deletion (will insert if it seems relevant, just ask)
})
})
The error message is "AccIdNotFound"
console.log returns 5 (same as the logged in user) and undefined

Answer 1

db.all delivers an array of rows, not just one row. You are assuming the result is a single comment only.
You should check result.length, then pull out result[0].