Wordpress數據庫自定義查詢來驗證數據

Question

我無法找到自定義查詢的任何語法，使用$ wpdb對我來說是新的，所以任何人都可以幫助我解決這個問題？

if(isset($_POST['submit'])) 
{ 
    global $wpdb; 
    $tablename='wp_form_subscribe'; 

    $myrows = $wpdb->get_results("SELECT * FROM wp_form_subscribe where  email=$wpdb->email"); 
    if($myrows==0) 
    { 
    $data=array(
    'name' => $_POST['fullname'], 
    'age' => $_POST['age'], 
    'email' => $_POST['email']); 
    $wpdb->insert($tablename, $data); 
    } 
    else 
    { 
    $status='User already subscribed'; 
    } 
    $status=''; 
    } 

Answer 1

WordPress的定義了一個名爲wpdb類，它包含了一組用於與數據庫交互功能。

Reference Link for $wpdb

如果要檢查電子郵件您的表wp_form_subscribe

 $status=''; 

if(isset($_POST['submit'])) 
{ 
     global $wpdb; 

     $tablename = 'wp_form_subscribe'; 
     $email = esc_sql($_POST['email']); 

     // Execute the Query 
     $wpdb->get_results("SELECT * FROM wp_form_subscribe where  email = '$email' "); 
     // Check for row exists with the email you provided. 

     $rowCount = $wpdb->num_rows; 

     if($rowCount == 0) 
     { 
     $data=array(
        'name' => $_POST['fullname'], 
        'age' => $_POST['age'], 
        'email' => $_POST['email'] 
        ); 


     $wpdb->insert($tablename, $data); 

     $status='User successfully subscribed'; 

     } 
     else 
     { 
    $status='User already subscribed'; 
     } 
    echo $status; 
}