Question

这似乎很容易，但我被困在某个地方。我试图查看用户何时注册该电子邮件是否已经在数据库中，简单。

HTML：

        <form class="reg-page" name="register" action="<?php qsmp_register( $_POST['qsmp_name'],
                                                                            $_POST['qsmp_email3'],
                                                                            $_POST['qsmp_password3'],
                                                                            $_POST['qsmp_terms'],
                                                                            $_POST['qsmp_newsletter']) ?>" method="post">
            <div class="reg-header">
                <h2>Register a new account</h2>                  
            </div>

            <label>Name <span class="color-red">*</span></label>
            <input type="text" class="form-control margin-bottom-20" size="100" name="qsmp_name" required>

            <label>Email Address <span class="color-red">*</span></label>
            <input type="email" class="form-control margin-bottom-20" name="qsmp_email3" required>

            <div class="row">
                <div class="col-sm-6">
                    <label>Password <span class="color-red">*</span></label>
                    <input size="20" type="password" class="form-control margin-bottom-20" name="qsmp_password3" required>
                </div>
                <div class="col-sm-6">
                    <label>Confirm Password <span class="color-red">*</span></label>
                    <input size="20" type="password" class="form-control margin-bottom-20" required>
                </div>
            </div>

            <hr>

            <div class="row">
                <div class="col-lg-6">
                    <label class="checkbox">
                        <input type="checkbox" name="qsmp_terms" required> 
                        I read <a href="http://www.braziliansocialdance.co.uk/terms/" class="color-green">Terms and Conditions</a>
                    </label>    
                    <label class="checkbox">
                        <input type="checkbox" checked="true" name="qsmp_newsletter"> 
                         Sign up newsletter
                    </label>                        
                </div>
                <div class="col-lg-6 text-right">
                    <button class="btn-u" type="submit" name="register">Register</button>                        
                </div>
            </div>
        </form>

PHP（在fucntions.php中）：

$table_name = $wpdb->prefix . 'qsmp_mails';

$query = $wpdb->prepare( "SELECT COUNT(*) FROM %s WHERE email = %s ", $table_name, $mail );

echo $query;

$cEMAIL = $wpdb->get_var( $query );
echo $cEMAIL ;
if ($cEMAIL < 1 && !empty($mail))
{

但它不起作用，任何人都知道为什么？提前谢谢！

Answer 1

永远不应该直接调用wpdb（）类中的方法。您需要首先使用全局$ wpdb对象（有关更多信息，请阅读Class Reference/wpdb）。

在你的functions.php中试试这样的事情：

global $wpdb;
$query->query_where .= $wpdb->prepare( " AND $wpdb->users.email = %s", $mail ); // where $mail should be the user email you are looking for
echo $query;
$cEMAIL = $wpdb->get_var($query);
echo $cEMAIL ;

wordpress select count不返回值

1 个答案: