Insert session data into postgres database in Nodejs Expess app - sql

Question

I have an Nodejs express function where I am trying to insert data that is stored in the browser session into my postgres database. When I have the insert statement like this, the insert works but the session-stored customer_id isn't inserted and is just left null.
On the line with "var sql = INSERT INTO journal....", the values $1 and $2 are from user input and work correctly.
How can I get value 3 of the customer_id stored in the session to insert correctly? I would appreciate any advice or greater understanding.
app.post("/addJournalEntry", addJournalEntry);
function addJournalEntry(req, res) {
console.log("Posting data");
// var id = req.query.id;
//body is for post, query is for get
const customer_id = req.session.customer_id;
const journal_entry_date = req.body.journal_entry_date;
const journal_entry = req.body.journal_entry;
const params = [journal_entry, journal_entry_date, customer_id];
addEntryFromDataLayer(params, function (error, addEntry) {
console.log("Back From the addEntryFromDataLayer:", addEntry);
if (error || addEntry == null) {
res.status(500).json({
success: false,
data: error
});
}
else {
// res.json(result);
res.status(200).json(addEntry);
}
});
}
function addEntryFromDataLayer(params, callback) {
console.log("addEntryFromDataLayer called with id");
var sql = "INSERT INTO journal (journal_entry, journal_entry_date, customer_id) VALUES($1::text, $2::text, $3)";
// var params = [id];
pool.query(sql, params, function (err, addEntry) {
if (err) {
console.log("error in database connection");
console.log(err);
callback(err, null);
}
console.log("Found DB result:" + JSON.stringify(addEntry));
callback(null, addEntry);
});
}