PHP选择列表 - 在数据库中插入多个值

Question

I'm trying to insert multiple values in the database using select list. What I got so far:

HTML

<form enctype="multipart/form-data" action="" method="post">
            <select name="cars[]" multiple="multiple" style="width:300px">
            <?php 
            $getcars = mysql_query("SELECT cars_id, cars_name FROM car");
            while ($row = mysql_fetch_assoc($getcars)) {
                $car_id = $row['cars_id'];
                $car_name = $row['cars_name'];
            ?>
            <option value="<?php echo $car_id ?>"><?php echo $car_name ?></option>
            <?php } ?>
            </select><br />
            <input type="submit" name="submit" value="Submit"/><br/>
        </form> 

PHP

        $cars= $_POST['cars'];
        echo $cars;
        for($i = 0; $i < count($cars); $i++){
            echo $cars[$i];
            $carGroups = mysql_query("INSERT INTO car_groups VALUES('$company','$cars[$i]]')"); 
        }

Unfortunately it doesn't work, I tried to print $cars to check the resulted value. It prints "Array", and when I tried to print $cars[$i] it prints nothing.

Does anyone know what the problem is?

Answer 1

There is an extra closing bracket that should be removed. You are not checking if your query was successful or not.

$carGroups = mysql_query("INSERT INTO car_groups VALUES('$company','$cars[$i]]')"); 

should be:

$carGroups = mysql_query("INSERT INTO car_groups VALUES('$company','$cars[$i]')") or die(mysql_error()); 

Since $cars is an array, you can print its content using print_r or var_dump:

print_r($cars);
var_dump($cars);

Useful reading:
How to get useful error messages in PHP?
mysql_* functions are deprecated