MySQL 8.0

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CREATE TABLE managers (
  `clientId` INTEGER,
  `managerId` INTEGER
);

INSERT INTO managers
  (`clientId`, `managerId`)
VALUES
  ('1', '1'),
  ('2', '2'),
  ('3', '3');
CREATE TABLE Clients (
  `Id` INTEGER,
  `Client` VARCHAR(1),
  `Status` VARCHAR(8)
);

INSERT INTO Clients
  (`Id`, `Client`, `Status`)
VALUES
  ('1', 'A', 'Active'),
  ('2', 'B', 'Active'),
  ('3', 'C', 'Inactive');
CREATE TABLE users (
  `id` INTEGER,
  `firstName` VARCHAR(7)
);

INSERT INTO users
  (`id`, `firstName`)
VALUES
  ('1', 'Carrera'),
  ('2', 'Taylor'),
  ('3', 'Diaz');
SELECT c.`Id` as ClientId ,u.id as ManagerId  FROM users u CROSS JOIN Clients c
WHERE c.`Status` = 'Active' AND (u.id,c.`Id`) NOT IN (SELECT `clientId`, `managerId` FROM managers)
ORDER By ClientId,ManagerId


ClientId
ManagerId


1
2

1
3

2
1

2
3