收到“您的SQL语法有错误”错误-PHP，MySQL

Question

I am writing an "Edit" page that gets the information from the database and show it in a form, and lets the user modify it by click Edit. However, I am getting this error:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 's notes ...' WHERE id = 2' at line 5

I've checked my code a lot in order to figure it out, but had no luck. Here's my code :

<?php
    if (isset($_POST["submit"])) {
        $ind_name = $_POST["ind_name"];
        $age = $_POST["age"];
        $gender = $_POST["gender"];
        $notes = $_POST["notes"];
        $query = "UPDATE individual SET 
                    ind_name = '{$ind_name}',
                    age = {$age},
                    gender = '{$gender}',
                    notes = '{$notes}'
                    WHERE id = {$_GET["ind"]} ";
        $result = mysql_query($query);
        if (mysql_affected_rows () == 1) {
            header("Location: edit_ind.php?ind={$_GET["ind"]}");
        } else {
            echo "ERROR : " . mysql_error();
        }
    }
?>

And here's my html form code:

<form action="edit_ind.php?ind=<?php echo $_GET["ind"]; ?>" method ="post" >
    <div id="formWrapper_ind">
        <label for="ind_name">Individual Name : </label>
        <?php $ind_name_form = get_ind_info_ind("ind_name"); ?>
        <input type="text" placeholder="Individual Name" name="ind_name" value="<?php echo $ind_name_form; ?>" required>
        <br/>

        <label for="age">Age : </label>
        <?php $ind_age_form = get_ind_info_ind("age"); ?>
        <input type="text" name="age" placeholder="Age" value="<?php echo $ind_age_form; ?>" required>
        <br/>

        <label for="gender">Gender : </label>
        <div id="radios">
            <?php $ind_gender_form = get_ind_info_ind("gender"); ?>
            <p><input type="radio" name="gender" value="Male" <?php if ($ind_gender_form== 'Male') {echo "checked"; } ?>>  Male
            <input type="radio" name="gender" value="Female" <?php if ($ind_gender_form == 'Female') {echo "checked"; } ?>>  Female</p>
        </div>
        <br/>

        <label for="notes">Notes : </label>
        <?php $ind_notes_form = get_ind_info_ind("notes"); ?>
        <textarea placeholder="Individual Notes..." name="notes"><?php echo $ind_notes_form; ?></textarea>
        <div id="buttons">
            <input type="reset" value="Reset">
            <input type="submit" name="submit" value="Done">
        </div>
    </div>
</form>

I can't find the syntactic error in my SQL code, please take a look at it. Thanks in advance.

Answer 1

You need to escape all the variables used in the query:

$ind_name = mysql_real_escape_string($_POST["ind_name"]);
$age = intval($_POST["age"]);
$gender = mysql_real_escape_string($_POST["gender"]);
$notes = mysql_real_escape_string($_POST["notes"]);
$ind = intval($_GET["ind"]);

$query = "UPDATE individual SET 
            ind_name = '$ind_name',
            age = $age,
            gender = '$gender',
            notes = '$notes'
            WHERE id = $ind";

Answer 2

您可以从输出查询开始。

Answer 3

您确定$_GET["ind"]}是整数吗？

Answer 4

Change WHERE id = {$_GET["ind"]} "; to this:

WHERE id = ". $_GET["ind"];

Please note that it's open for SQL injections!!

Answer 5

Here is your problem:

WHERE id = {$_GET["ind"]} ";

You're using doublequotes.

Answer 6

You really shouldn't be playing with $_GET this way:

$query = "UPDATE individual SET 
                ind_name = '{$ind_name}',
                age = {$age},
                gender = '{$gender}',
                notes = '{$notes}'
                WHERE id = {$_GET["ind"]} ";

I strongly suggest you to concat it like WHERE id = " . $_GET['ind'] . "";

SQL injection

You should be really careful with the code you just posted because it can easily be injected with malicious code. Always sanitze your variables . Any input the user gives you assume it's BAD and they want to use it against your app.