Provides a way to use multiple fields to match a record in the database when importing or adding new records in Participants Database

pdb-match-multiple-fields.php

<?php
/**
 * Plugin Name: PDB Multiple Field Match Check
 * Description: checks a new Participants Database submission against the database for a matching record using multiple fields
 * Version: 2.1
 * 
 * requires PDB version 1.9.4.2 or later
 */
add_action( 'pdb-incoming_record_match_object', 'xnau_check_for_match' );
  
// set up our custom feedback message
add_filter( 'pdb-validation_error_messages', 'xnau_check_for_match_feedback' );

/**
 * checks the incoming submission for a match in the database
 *
 * @global wpdb $wpdb
 * @param \PDb_submission\incoming_record_match $record_match the record match object
 */
function xnau_check_for_match( $record_match )
{ 
  // edit this array to set up your match fields
  $check_fields = array( 'first_name', 'last_name' );
  
  $match_status = false; // assume no match
  
  $post = $record_match->post;
  
  $where = array();
  $values = array();
  
  $exception = '';
  
  /* 
   * don't include the record id to prevent attempting to add a new record with 
   * the same id as an existing record
   * 
   */
  if ( isset( $post['id'] ) ) {
    unset( $post['id'] );
  } 
  
  // put together the list of match fields and values
  foreach ($check_fields as $field) {
    if ( isset( $post[$field] ) ) {
      $where[] = '`' . $field . '` LIKE "%s"';
      $values[] = trim( $post[$field] );
    }
  }
  
  if ( count( $where ) === 0 ) {
    //nothing to check
    return false;
  }
  
  // build the query to find our match
  $sql = 'SELECT id FROM ' . Participants_Db::$participants_table . ' WHERE ' . $exception . '(' . implode( ' AND ', $where ) . ')';
  global $wpdb;
  $result = intval( $wpdb->get_var( $wpdb->prepare( $sql, $values ) ) );
  
  // log the query and results if debugging
  if (PDB_DEBUG) {
    ob_start();
    var_dump($result);
    Participants_Db::debug_log(__FUNCTION__.' match mode: '.$record_match->match_mode().' 
query: '. $wpdb->last_query . ' 
result: '. ob_get_clean() );
  }
  
  /*
   * the $result will be the id of the matched record or 0 if no match
   */
  if ( $result > 0 ) {
    
    // provide the ID of the matched record to the object
    $record_match->set_record_id( $result );
    
    // we found a match set status to true
    $match_status = true;
  }
  
  // set the match status in the match object
  $record_match->set_match_status( $match_status );
}

/**
 * adds a feedback message for signup submissions
 * 
 * this message will be shown if the signup is rejected because it matches an 
 * existing record
 * 
 * @param array $messages
 * @return array
 */
function xnau_check_for_match_feedback( $messages )
{
  // clear the error CSS so the wrong field does not get highlighted
  add_filter( 'pdb-error_css', function ($css) {
    return '';
  } );
  
  // set the feedback message
  $messages['duplicate'] = 'You must choose a different First Name or Last Name, the name you submitted matches an existing record.';
  
  return $messages;
}