Codeigniter - 仅当数据库中不存在电子邮件时才更新电子邮件

I have an update page for my users where they can edit their name, email and other info.

So far, they can edit everything. Including their email. They can enter an email that already exists in the database without any issue.

I have tried adding this form validation rule

$this->form_validation->set_rules('email', 'Email', 'trim|required|xss_clean|is_unique[users.email]');

But that doesn't help because it will ask the user to enter another email if they click the save button, even if they don't want to change their email.

I just want to make it so that when they click the save button, only update the email if the user has changed it AND check that the email doesn't exist in the database before saving.

I have tried doing this but no luck.

The code that I'm playing with:

$first_name = $this->input->post('first_name');
    $last_name = $this->input->post('last_name');
    $email = $this->input->post('email');
    $uid = $this->session->userdata('uid');

    //$query = $this->db->get('dayone_entries');
    $query = $this->db->query('SELECT uid, email FROM users');


    $sql = "UPDATE users SET first_name = '{$first_name}', last_name = '{$last_name}', email = '{$email}' WHERE uid = $uid LIMIT 1";
    $this->db->query($sql);

    if ($this->db->affected_rows() === 1) {

        return true;
    } else {
        return false;
    }

You can try the following code :

$this->form_validation->set_rules('email', 'lang:email', 'trim|required|valid_email|callback__is_unique_email[email]');

and the callback function should look like this :

public  function _is_unique_email($value, $field){
    $result = $this->db->where('uid !=', $this->session->userdata('uid'))
                    ->where($field, $value)
                    ->get('users')
                    ->row_array();

    if ($result) {
        $this->form_validation->set_message('_is_unique_email', $this->lang->line('_is_unique_'));
        return false;
    }

    return true;
}

use validate library : http://docs.jquery.com/Plugins/Validation/Methods/remote

your javascript :

$("#yourFormId").validate({
        rules: {
            email: {
                required: true,
                email: true,
                remote: {
                    url: "checkmail.php",
                    type: "post"
                 }
            }
        },
        messages: {
            email: {
                required: "Please Enter Email!",
                email: "This is not a valid email!",
                remote: "Email already in use!"
            }
        }
    });

checkmail.php:

<?php
$registeredEmails = array('test1@test.com', 'test2@test.com', 'test3@test.com');

$requestedEmail  = $_POST['email'];

if( in_array($requestedEmail, $registeredEmails) ){
    echo 'false';
}
else{
    echo 'true';
}
?>

if you use codeigniter means use checkmail.php as a controller function.. you can pass your $registeredEmails array values as $registeredEmails[] = "your query result which is in for loop".

Your Javascript file:

$("#form_id").validate({
        rules: {
            email: {
                required: true,
                email: true,
                remote: {
                    type: "post",
                    url: "pathtocontroller/controller.php/checkEmail",
                 }
            }
        },
        messages: {
            email: {
                required: "Please enter Email!",
                email: "Please enter valid Email!",
                remote: "Email already not available!"
            }
        }

Your Controller File:

function checkEmail() {
        $userArr = $this->input->post();
        $id = $this->session->userdata('id');//if you have stored id within session else pass it within remote function
        if (isset($userArr["email"])) {
            if ($id != '') {
                $ext_cond = "id !='" . $id . "'";
            }
            echo $this->your_model_name->getUserValidation('your_email_field_name', $userArr['email'], $ext_cond);
            exit;
        }
        exit;
    }

Your Model:

public function getUserValidation($usertype = '', $value = '', $cond = '') {

        if ($usertype != '' && $value != '') {
            $this->db->select($usertype);
            $this->db->from($this->main_table);
            if ($cond != '') {
                $this->db->where($cond);
            }

            if (is_array($usertype)) {
                foreach ($usertype as $key => $type_value) {
                    $this->db->where($type_value, $value[$key]);
                }
            } else {
                $this->db->where($usertype, $value);
            }

            $user_data = $this->db->get()->result_array();
//            echo $this->db->last_query();exit;
            if (is_array($user_data) && count($user_data) > 0) {
                return "false";
            } else {
                return "true";
            }
        } else {
            return "false";
        }
    }