INSERT查询在php中使用mysql返回false。 使用msqli_query（$ dbcon，query）

Question

I am trying to INSERT data into a table and I am using mysqli API executing query.

$insert = "INSERT INTO pdhp_patient 
                   (username, password, email, first_name,     
                    last_name, dob, gender, s_s_n, i_n) 
            VALUES ('$username', '$password', '$email', '$first_name', 
                    '$last_name', '$dob', '$gender', '$s_s_n', '$i_n');";

This is the query I am trying to execute.

mysqli_query($connection, $insert); 

The previous line of code is for executing the query. This time the query returns false. I am unable to understand what the mistake is I Have even tried without the single quotes in the query. This however does not work.

Editted:

$username = $_POST['username'];
$password = $_POST['password'];
$email = $_POST['email'];
$first_name = $_POST['first_name'];
$last_name = $_POST['last_name'];
$dob = $_POST['dob'];
$dob = date("m-d-Y", strtotime($dob));
$gender = $_POST['gender'];
$cid = $_POST['country'];
$sid = $_POST['city'];
$s_s_n = $_POST['s_s_n'];
$i_n = $_POST['i_n'];

global $connection;




if(isset($_POST['type']) && $_POST['type']==="patient"){
    $insert = "INSERT INTO pdhp_patient (username, password, email, first_name, last_name, dob, gender, s_s_n, i_n) VALUES ('$username', '$password', '$email', '$first_name', '$last_name', '$dob', '$gender', '$s_s_n', '$i_n');";

    $insert = mysql_prep($insert);

        $result = mysqli_query($connection, $insert); 
if ( $result === false ) {
echo mysqli_error($connection);
exit;
}
        if($val){
        echo "This must be working";
    }else{
        echo "This was not working";
    }
}elseif(isset($_POST['type']) && $_POST['type']==="doctor"){
    $insert = "INSERT INTO pdhp_doctor (username, password, email, first_name, last_name, dob, gender, s_s_n, i_n) VALUES ($username, $password, $email, $first_name, $last_name, $dob, $gender, $s_s_n, $i_n);";
    $insert = mysql_prep($insert);
    mysqli_query($connection, $insert);
}elseif(isset($_POST['environment_radio']) && $_POST['type']==="environment"){
    $insert = "INSERT INTO pdhp_environmentalist (username, password, email, first_name, last_name, dob, gender, s_s_n, i_n) VALUES ($username, $password, $email, $first_name, $last_name, $dob, $gender, $s_s_n, $i_n);";
    $insert = mysql_prep($insert);
    mysqli_query($connection, $insert);
}

Some more code for proper info. This code chunk is what I wanna achieve. this is the full code. Thanks.

Answer 1

Give a man a fish, he eats today. Teach a man to fish, he eats everyday

Add some error checking

$insert = "INSERT INTO pdhp_patient 
                   (username, password, email, first_name,     
                    last_name, dob, gender, s_s_n, i_n) 
            VALUES ('$username', '$password', '$email', '$first_name', 
                    '$last_name', '$dob', '$gender', '$s_s_n', '$i_n');";


$result = mysqli_query($connection, $insert); 
if ( $result === false ) {
    echo mysqli_error($connection);
    exit;
}

Then you can probably fix your own errors