我正在编辑一个插件的代码，以添加我需要的一个小功能。我几乎成功了，但我真的很挣扎，不明白为什么

$user_id_for_um_groups = get_user_by( \'email\', $email );

我在数据库的user\\u id2列中获得0（我需要获得用户ID）。

我在下面粘贴了完整的代码，我添加的代码被注释为“添加的代码”。

我将非常感谢您的帮助，因为我已经花了几天时间试图理解为什么它不起作用。谢谢；-）

<?php
public function bulk_add_users() {
    if ( isset( $_GET[\'action\'] ) && \'bulk-add-users\' === $_GET[\'action\'] && isset( $_GET[\'group-id\'] ) ) {
        $group_id       = absint( $_GET[\'group-id\'] );
        $first_names    = $_REQUEST[\'first_name\'];
        $last_names     = $_REQUEST[\'last_name\'];
        $emails         = $_REQUEST[\'email\'];
        $error_results  = [];
        $insert_results = [];
        if ( $emails ) {
            $role = apply_filters( \'uo-groups-user-role\', get_option( \'default_role\', \'subscriber\' ) );
            foreach ( $emails as $k => $email ) {
                if ( ! empty( $email ) ) {
                    if ( is_email( $email ) ) {
                        $first       = $first_names[ $k ];
                        $last        = $last_names[ $k ];
                        $email       = sanitize_email( $email );
                        $is_existing = email_exists( $email );

                        if ( is_numeric( $is_existing ) ) {
                            $user_id     = $is_existing;
                            $user_groups = learndash_get_users_group_ids( $user_id, true );
                            if ( in_array( $group_id, $user_groups ) ) {
                                $error_results[] = sprintf( __( \'Line #%d: %s is existing user of group.\', \'uncanny-learndash-groups\' ), $k + 1, $email );
                                continue;
                            }
                            $user_data = array(
                                \'user_email\' => $email,
                                \'user_id\'    => $user_id,
                                \'first_name\' => $first,
                                \'last_name\'  => $last,
                                \'role\'       => $role,
                            );

                            if ( isset( $user_data[\'first_name\'] ) && ! $is_existing ) {
                                update_user_meta( $user_id, \'first_name\', $user_data[\'first_name\'] );
                            }

                            if ( isset( $user_data[\'last_name\'] ) && ! $is_existing ) {
                                update_user_meta( $user_id, \'last_name\', $user_data[\'last_name\'] );
                            }

                            $restApi = new RestApiEndPoints();
                            $restApi->add_existing_user( $user_data, false, $group_id, 0, \'not redeemed\', false );

                        } else {
                            $user_data = array(
                                \'user_login\' => $email,
                                \'user_email\' => $email,
                                \'first_name\' => $first,
                                \'last_name\'  => $last,
                                \'role\'       => $role,
                                \'group_id\'   => $group_id,
                            );
                            $restApi   = new RestApiEndPoints();
                            $restApi->add_invite_user( $user_data, false, false, false );

                        }
                        $insert_results[] = sprintf( __( \'%s added & invited successfully.\', \'uncanny-learndash-groups\' ), $email );

                    //ADDED CODE
                     global $wpdb;

                     $user_id_for_um_groups = get_user_by( \'email\', $email );

                     $current_group_id_for_um_groups = $wpdb->get_var("SELECT ID FROM wpso_posts WHERE post_excerpt = $group_id");
                     $current_user_id_for_um_groups = get_current_user_id();
                     $wpdb->insert( \'wpso_um_groups_members\', array( 
                     \'group_id\' => $current_group_id_for_um_groups,
                     \'user_id1\' => $user_id_for_um_groups,
                     \'user_id2\' => $current_user_id_for_um_groups,
                     \'status\' => \'approved\',
                     \'role\' => \'member\') );
                    //END OF ADDED CODE

                    } else {
                        $error_results[] = sprintf( __( \'Line #%d: Email (%s) not correct.\', \'uncanny-learndash-groups\' ), $k + 1, $email );
                    }
                } else {
                    if ( ! empty( $first_names[ $k ] ) || ! empty( $last_names[ $k ] ) ) {
                        $error_results[] = sprintf( __( \'Line #%d: Email field is empty.\', \'uncanny-learndash-groups\' ), $k + 1 );
                    }
                }
            }
        }
        $url = SharedFunctions::get_group_management_page_id( true );
        $url .= \'?group-id=\' . $group_id;
        $url .= \'&bulk=1\';
        if ( ! empty( $error_results ) ) {
            $url .= \'&bulk-errors=\' . urlencode( join( \'<br /> \', $error_results ) );
        }
        if ( ! empty( $insert_results ) ) {
            $url .= \'&success-invited=\' . urlencode( join( \'<br /> \', $insert_results ) );
        }

        wp_safe_redirect( $url );
        exit;
    }
}