mysql- storing large dollar amounts

Short, practical notes tied to the replies here.

As @fuston05 discovered, the root cause is applying display formatting before the insert. Thousands separators or currency symbols turn the input into a non‑pure numeric string; MySQL will stop parsing at the first non‑numeric character, so you get wrong/truncated values. @smantscheff’s idea of replacing separators can work, but it’s safer and more predictable to sanitize in the application layer and keep formatting strictly for presentation.

Use a fixed‑point column for money (not FLOAT). Pick precision to cover your largest amounts; M is total digits and D is decimals, so DECIMAL(M,2) gives you M−2 integer digits plus two cents. Example schema:

amount DECIMAL(12,2) NOT NULL DEFAULT '0.00'

Sanitize input before sending to SQL and bind parameters (avoid calling number_format() before storage). Example PHP flow (illustrative):

$raw = $_POST['amount'];      // e.g. "$1,234.56"
$clean = preg_replace('/[^\d\.\-]/', '', $raw); // "1234.56"
$clean = preg_replace('/(\..*)\./', '$1', $clean); // remove extra dots
$stmt = $pdo->prepare("INSERT INTO payments (amount) VALUES (:amount)");
$stmt->execute([':amount' => $clean]);

Alternative: store amounts as integer cents to avoid any decimal handling:

$cents = (int) round((float)$clean * 100);
INSERT INTO payments (amount_cents) VALUES (?);

Quick troubleshooting checklist: confirm the bound value (log it) before execute, verify the column type is DECIMAL (or integer cents), and keep number_format() or locale formatting for display code only. This approach prevents the comma/thousands‑separator issue and keeps values accurate over time.