Invalid use of group function Error in MariaDB - Update Query and SUM - sql

Question

So im trying to write an update query that either updates the funds of a user based on if they have visa or MasterCard.
What im trying to state here, and which im thinking is what causes the error, is to update the sum if the current balance and wanted withdraw amount is less than 10.000. If that is not the case and the visa balance becomes less than 0, im creating an intentional error so that i can use it later to redirect the user to an error page (i know its not the most PC way to do it).
This is how the code looks:
const connection = require('../models/loginrouters');
function takeMoney(amount, cardnumber) {
// prettier-ignore
console.log("db cardnumber is".cardnumber)
console.log('db amount is', amount);
connection.query(
"UPDATE users.usercards SET Balance = CASE WHEN type = 'visa' AND balance>'" +
amount +
"' THEN Balance - '" +
amount +
"' ELSE CASE WHEN type='mastercard' AND SUM(balance - '" +
amount +
"')<'-10000' THEN Balance - '" +
amount +
"' ELSE 'NEIN CASH' END END WHERE CardNumber = '" +
cardnumber +
"';",
function(err) {
if (err) {
console.log('You too poor');
console.log(err);
} else {
console.log('You got the cash');
}
}
);
}
module.exports = takeMoney;
When this query is run I get the following error:
Error: ER_INVALID_GROUP_FUNC_USE: Invalid use of group function
The query is posted to me as:
sql: 'UPDATE users.usercards SET Balance =
CASE WHEN type = \'visa\' AND balance>\'1000\'
THEN Balance - \'1000\'
ELSE
CASE WHEN type=\'mastercard\' AND SUM(balance - \'1000\')<\'-10000\'
THEN Balance - \'1000\'
ELSE \'NEIN CASH\'
END
END
WHERE CardNumber = \'123456\';'
In advance, thanks for your response!

Answer 1

So as Gordon Linoff stated in a comment, I cannot use SUM in an update query. I just wrapped it in a () and it works perfectly.
TLDR; DONT use SUM in an update query.
connection.query(
"UPDATE users.usercards SET Balance = CASE WHEN type = 'visa' AND balance>'" +
amount +
"' THEN Balance - '" +
amount +
"' ELSE CASE WHEN type='mastercard' AND (balance - '" +
amount +
"')>'-10000' THEN Balance - '" +
amount +
"' ELSE 'NEIN CASH' END END WHERE CardNumber = '" +
cardnumber +
"';",
function(err) {
if (err) {
console.log('You too poor');
} else {
console.log('You got the cash');
}
}
);
}