Mysql - 即使没有匹配也返回所有数据

Question

我已经使用左连接来返回我的 'allinvty3' 表中的所有数据，这是我的主文件，但它不起作用。它只会在我使用INNER时工作加入，但我想返回所有行，即使与我的所有表格都不匹配（ 条形码，adjust_tb，branchtobranch_tb等 。）

  <?php
require_once 'global.php';
if($_POST['type'] == 'item_tb'){
$row_num = $_POST['row_num'];
$result = mysqli_query($conn, "select ite_desc,ecr_desc, pric_cash, uom_lo, t.itemcode  as itemcode ,sum(t.qty) as tqty
            from ( 
            select ite_desc,ecr_desc,  pric_cash,   itemcode, uom_lo, qty   from allinvty3 as bc left JOIN barcode as ait on bc.in_code = ait.itemcode where ait.status='COMPLETE'
            union all
                select ite_desc,ecr_desc,  pric_cash,   itemcode, uom_lo,qty  from allinvty3 as bb left JOIN branchtobranch_tb as ait on bb.in_code = ait.itemcode
            union all
            select ite_desc,ecr_desc,  pric_cash,   itemcode, uom_lo,qty  from allinvty3 as sb left JOIN stockreturn_tb as ait on sb.in_code = ait.itemcode
             union all
            select ite_desc,ecr_desc,    pric_cash, itemcode, uom_lo,qty from allinvty3 as adt left JOIN adjustment_tb as ait1 on adt.in_code = ait1.itemcode where ait1.status='APPROVED'
            union all
                select ite_desc,ecr_desc,  pric_cash,   itemcode, uom_lo, qty  from allinvty3 as nt left JOIN notinclude_tb as ait on nt.in_code = ait.itemcode
          union all
            select ite_desc,ecr_desc,   pric_cash, itemcode, uom_lo, (qty * -1) from allinvty3 as slp left JOIN soldout_pd as ait2 on slp.in_code = ait2.itemcode) as t
           where ecr_desc LIKE '".strtoupper($_POST['name_startsWith'])."%'  group by itemcode        ")  ; 
            $data = array();
            while ($row = mysqli_fetch_assoc($result)) {
                $item =   $row['ecr_desc'].  '|' . $row['ite_desc'].'|'  .$row['itemcode'].  '|'  .$row['tqty'].'|'.  $row_num;
                array_push($data, $item);   
        }
         echo json_encode($data);

}
            ?>