PDOStatement :: execute（）：SQLSTATE [HY093]错误[关闭]

I see this error. Would you help me? Thanks

Warning: PDOStatement::execute(): SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens in C:\xampp\htdocs\add.php on line 13

add.php

<?php
require_once 'connect.php';
if (isset($_POST['date'], $_POST['name'])) {
    $date = $_POST['date'];
    $name = $_POST['name'];
    $cac = $_POST['cac'];
    $caa = $_POST['caa'];
    $cc = $_POST['cc'];
    $dac = $_POST['dac'];
    $daa = $_POST['daa'];
    $dc = $_POST['dc'];
    $query = $db->prepare("INSERT INTO transaction SET date = ?, name = ?, cac = ?, caa = ?, cc =, dac = ?, daa = ?, dc = ?"); 
    $insert = $query->execute(array( $date, $name, $cac, $caa, $cc, $dac, $daa, $dc));
    header("refresh:11;url=index.php");
}
else {echo "We have a problem";
    header("refresh:1;url=index.php");
    }
?>

INSERT INTO transaction SET date = ?, name = ?, cac = ?, caa = ?, cc = ?, dac = ?, daa = ?, dc = ?
-----------------------------------------------------------------------^

miss a ? after cc =