ka215

<?php
// As a prerequisite, there are stored each user ID to the "user_id" column (as numric type) in the "your_table_name" as target table. 
// (対象テーブル「your_table_name」には「user_id」カラム（数値型）にユーザーIDが格納されているという前提)

function custom_filter_get_data_sql( $sql, $table_name, $sql_clauses ) {
  if ( ! is_admin() && "your_table_name" === $table_name ) {
    $_current_user_id = 0; // For guest user
    if ( is_user_logged_in() ) {
      $current_user = wp_get_current_user();
      $_current_user_id = $current_user->ID;