SQL Server 2017

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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);
11 rows affected

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 >= '20180101' -- IS IT A TEXT OR A DATE FIELD?
            ) P
WHERE     PAWHLO = 'h550'
AND       PAANTX > 0
ORDER BY  PAANUM, PLANNED DESC


SKU
ON_STOCK
PLANNED


1
100
75

1
100
75

1
100
60

1
100
50

3
50
50


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 >= '20180101' -- IS IT A TEXT OR A DATE FIELD?
           GROUP BY P1MTRL) P
ON        P.P1MTRL = PAANUM
WHERE     PAWHLO = 'h550'
AND       PAANTX > 0
ORDER BY  PAANUM;


SKU
ON_STOCK
PLANNED


1
100
260

3
50
50