WooCommerce自定义字段未保存在数据库中

Question

我在主题functions.php文件的woocommerce注册页面中添加了一些自定义字段first_name，last_name，address，phone，但是该数据未保存在数据库中，该数据库假定要保存在wp_usermeta表中。我尝试了所有方法，但对我没有用。请找到下面的代码。

    //Add custom fields

function wooc_extra_register_fields() {?>
       <p class="form-row form-row-first">
       <label for="reg_billing_first_name"><?php _e( 'First name', 'woocommerce' ); ?><span class="required">*</span></label>
       <input type="text" class="input-text" name="billing_first_name" id="reg_billing_first_name" value="<?php if ( ! empty( $_POST['billing_first_name'] ) ) esc_attr_e( $_POST['billing_first_name'] ); ?>" />
       </p>
       <p class="form-row form-row-last">
       <label for="reg_billing_last_name"><?php _e( 'Last name', 'woocommerce' ); ?><span class="required">*</span></label>
       <input type="text" class="input-text" name="billing_last_name" id="reg_billing_last_name" value="<?php if ( ! empty( $_POST['billing_last_name'] ) ) esc_attr_e( $_POST['billing_last_name'] ); ?>" />
       </p>
        <p class="form-row form-row-wide">
       <label for="reg_billing_address"><?php _e( 'Address', 'woocommerce' ); ?></label>
       <input type="text" class="input-text" name="billing_address" id="reg_billing_address" value="<?php esc_attr_e( $_POST['billing_address'] ); ?>" />
       </p>
        <p class="form-row form-row-wide">
       <label for="reg_billing_phone"><?php _e( 'Phone', 'woocommerce' ); ?></label>
       <input type="text" class="input-text" name="billing_phone" id="reg_billing_phone" value="<?php esc_attr_e( $_POST['billing_phone'] ); ?>" />
       </p>
       <div class="clear"></div>
       <?php
 }
 add_action( 'woocommerce_register_form_start', 'wooc_extra_register_fields' );



// Validate fields

function wooc_validate_extra_register_fields( $username, $email, $validation_errors ) {
        if(isset($_POST['billing_first_name']) && empty($_POST['billing_first_name'])){
            $validation_errors->add('billing_first_name_error', __('First name is required','woocommerce'));
        }

        if(isset($_POST['billing_last_name']) && empty($_POST['billing_last_name'])){
            $validation_errors->add('billing_last_name_error', __('Last name is required!.', 'woocommerce'));
        }
        if(isset($_POST['billing_address']) && empty($_POST['billing_address'])){
            $validation_errors->add('billing_address_error', __('Address is required!.', 'woocommerce'));
        }

        if(isset($_POST['billing_phone']) && empty($_POST['billing_phone'])){
            $validation_errors->add('billing_phone_error', __('Phone is required!.', 'woocommerce'));
        }

         return $validation_errors;
}

add_action( 'woocommerce_register_post', 'wooc_validate_extra_register_fields', 10, 3 );


//save in database

function wooc_save_extra_register_fields( $customer_id ) {
    if ( isset( $_POST['billing_phone'] ) ) {
                 // Phone input filed which is used in WooCommerce
                 update_user_meta( $customer_id, 'billing_phone', sanitize_text_field( $_POST['billing_phone'] ) );
          }
      if ( isset( $_POST['billing_first_name'] ) ) {
             //First name field which is by default
             update_user_meta( $customer_id, 'first_name', sanitize_text_field( $_POST['billing_first_name'] ) );
             // First name field which is used in WooCommerce
             update_user_meta( $customer_id, 'billing_first_name', sanitize_text_field( $_POST['billing_first_name'] ) );
      }
      if ( isset( $_POST['billing_last_name'] ) ) {
             // Last name field which is by default
             update_user_meta( $customer_id, 'last_name', sanitize_text_field( $_POST['billing_last_name'] ) );
             // Last name field which is used in WooCommerce
             update_user_meta( $customer_id, 'billing_last_name', sanitize_text_field( $_POST['billing_last_name'] ) );
      }

}
add_action( 'woocommerce_created_customer', 'wooc_save_extra_register_fields' );