Joining two processed tables without Primary Key
I'm not sure if this is what are you looking for.

I've set up next example:




CREATE TABLE INDIVID (PAANUM INT, PAWHLO VARCHAR(10), PAANTX INT);
INSERT INTO INDIVID VALUES (1, 'h550', 100),(2, 'h560', 300),(3, 'h550', 50);

CREATE TABLE PORDHV (P1MTRL INT, P1STAT CHAR(1), P1PTF VARCHAR(10), P1UPL1 INT);
INSERT INTO PORDHV VALUES 
(1, 'A', '20180301', 50),
(1, 'T', '20180401', 50),
(1, 'A', '20180401', 75),
(1, 'A', '20180501', 60),
(2, 'A', '20180301', 50),
(2, 'A', '20180401', 75),
(3, 'A', '20180301', 50),
(1, 'A', '20180401', 75);
GO



If you're trying to get all orders, order by quantity you can use a CROSS APPLY solution:




SELECT    PAANUM AS SKU,
          PAANTX AS ON_STOCK,
          P.PLANNED
FROM      INDIVID
CROSS APPLY (SELECT P1UPL1 AS PLANNED
             FROM   PORDHV
             WHERE  P1MTRL = INDIVID.PAANUM
             AND    P1STAT NOT IN ('E','T','P','R')
             AND    PORDHV.P1PTF &gt;= '20180101' -- IS IT A TEXT OR A DATE FIELD?
            ) P
WHERE     PAWHLO = 'h550'
AND       PAANTX &gt; 0
ORDER BY  PAANUM, PLANNED DESC
GO



SKU | ON_STOCK | PLANNED
--: | -------: | ------:
  1 |      100 |      75
  1 |      100 |      75
  1 |      100 |      60
  1 |      100 |      50
  3 |       50 |      50



But it you want the sum of all orders by SKU you can sum all orders of each SKU and then LEFT JOIN with INDIVID table.




SELECT    PAANUM AS SKU,
          PAANTX AS ON_STOCK,
          P.PLANNED
FROM      INDIVID
LEFT JOIN (SELECT   P1MTRL, SUM(P1UPL1) AS PLANNED
           FROM     PORDHV
           WHERE    P1STAT NOT IN ('E','T','P','R')
           AND      PORDHV.P1PTF &gt;= '20180101' -- IS IT A TEXT OR A DATE FIELD?
           GROUP BY P1MTRL) P
ON        P.P1MTRL = PAANUM
WHERE     PAWHLO = 'h550'
AND       PAANTX &gt; 0
ORDER BY  PAANUM;
GO



SKU | ON_STOCK | PLANNED
--: | -------: | ------:
  1 |      100 |     260
  3 |       50 |      50



dbfiddle here