public function pledgePaymentResult(){

/*

원하는 sql문

SELECT A.price, A.extra_price, A.payment_date, C.member_name, C.login_chFROM payment as ALEFT JOIN project as BON A.project_id = B.project_idLEFT JOIN member as CON C.member_id = A.member_id

union

SELECT D.member_id, D.register_date, D.register_ip, D.sns , E.member_nameFROM pledge as DLEFT JOIN member as EON D.member_id = E.member_id\

*/

 $this->db->select('payment.price, payment.extra_price, payment.payment_date, member.member_name, member.login_ch');        

$this->db->from('payment');      

$this->db->join('project', 'payment.project_id=project.project_id', 'LEFT');        

$this->db->join('member', 'payment.member_id=member.member_id', 'LEFT');        

$this->db->get();        

$subquery1 = $this->db->last_query();

$this->db->select('pledge.member_id, pledge.register_date, pledge.register_ip, pledge.sns , member.member_name');        

$this->db->from('pledge');        

$this->db->join('member', 'pledge.member_id=member.member_id', 'LEFT');        

$this->db->get();      

 $subquery2 = $this->db->last_query();        

//$this->db->query('($subquery1) UNION ALL ($subquery2)');        

$query = $this->db->query($subquery1." UNION ".$subquery2);        

$pledgePayment_list = $this->db->get()->result_array();      

 print_r2($pledgePayment_list);    

}

이렇게 하면 

Error Number: 1096

No tables used

SELECT *

Filename: D:/xampp/htdocs/kim_sys/database/DB_driver.php

Line Number: 691

이렇게 나오네요 ㅠ,ㅠ

이거 원인이 무엇인가요? 

$subquery1 

$subquery2

각각 찍어보면 정상적으로 출력이 되는데요.

문제 해결 부탁드립니다 ㅠ,ㅠ