SQL Server 2022

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CREATE TABLE Queues (
  "QueueId" INTEGER,
  "ItemName" VARCHAR(6)
);

INSERT INTO Queues
  ("QueueId", "ItemName")
VALUES
  ('1', 'Pencil'),
  ('1', 'Eraser'),
  ('2', 'Pencil'),
  ('2', 'Eraser'),
  ('2', 'Ruler');

CREATE TABLE QueuesMeta (
  "QueuesMetaId" INTEGER,
  "QueueId" INTEGER,
  "Capacity" INTEGER,
  "IsCountMatch" VARCHAR(3)
);

INSERT INTO QueuesMeta
  ("QueuesMetaId", "QueueId", "Capacity", "IsCountMatch")
VALUES
  ('1', '1', '2', 'No'),
  ('2', '2', '3', 'No'),
  ('3', '1', '3', 'No'),
  ('4', '1', '1', 'No');
9 rows affected

UPDATE QM
SET IsCountMatch = 'Yes'
FROM QueuesMeta QM
WHERE EXISTS (SELECT 1
    FROM Queues Q
    WHERE QM.QueueId = Q.QueueId
    -- implicitly group by empty set
    HAVING QM.Capacity = COUNT(*)
)
  AND QM.IsCountMatch = 'No';
2 rows affected

SELECT * FROM QueuesMeta;


QueuesMetaId
QueueId
Capacity
IsCountMatch


1
1
2
Yes

2
2
3
Yes

3
1
3
No

4
1
1
No