아래 코드가 도움이 되실지...

// 모든 게시판 정보 가져오기
$board_query = "SELECT bo_table FROM {$g5['board_table']} WHERE bo_use_search = '1'";
$board_result = sql_query($board_query);

$data = array();
while ($board = sql_fetch_array($board_result)) {
    $bo_table = $board['bo_table'];
    
    // 각 게시판의 wr_1 필드 조회
    $query = "SELECT '{$bo_table}' as bo_table, wr_id, wr_subject, wr_1 
              FROM {$g5['write_prefix']}{$bo_table} 
              WHERE wr_1 IS NOT NULL AND wr_1 != '' AND wr_is_comment = 0";
    
    $result = sql_query($query);
    while ($row = sql_fetch_array($result)) {
        $data[] = $row;
    }
}

//특정게시글

SELECT 'notice' as bo_table, wr_id, wr_subject, wr_1 FROM g5_write_notice WHERE wr_1 IS NOT NULL AND wr_1 != ''
UNION ALL
SELECT 'free' as bo_table, wr_id, wr_subject, wr_1 FROM g5_write_free WHERE wr_1 IS NOT NULL AND wr_1 != ''
UNION ALL
SELECT 'gallery' as bo_table, wr_id, wr_subject, wr_1 FROM g5_write_gallery WHERE wr_1 IS NOT NULL AND wr_1 != '';