Never apply fixes directly to production. Create a staging environment:

mysqlcheck -u root -p --auto-repair --all-databases

// Replace floating-point calculation with integer math (store in cents) class TaxCalculator public function calculateTax($subtotal_cents, $tax_rate) // Convert to integer to avoid floating point errors $tax_cents = (int)round($subtotal_cents * ($tax_rate / 100)); return $tax_cents;