SELECT       o.OrderNo,         o.OrderDate,
             SUM(oi.Amount) AS  TotalOrderAmount
FROM         Orders         AS  o
INNER JOIN   OrderItems     AS  oi
      ON     oi.OrderNo      =  o.OrderNo
WHERE        o.CustomerNo    =  @CustomerNo
GROUP BY     o.OrderNo,         o.OrderDate
HAVING NOT EXISTS
 (SELECT     *
  FROM       Orders         AS  o2
  INNER JOIN OrderItems     AS  oi2
        ON   oi2.OrderNo     =  o2.OrderNo
  WHERE      o2.OrderNo     <>  o.OrderNo
  AND        o2.OrderDate    =  o.OrderDate
  GROUP BY   o2.OrderNo
  HAVING     COUNT(oi2.ItemCode) <> COUNT(oi.ItemCode));

HAVING       COUNT(oi.ItemCode) <> ALL
 (SELECT     COUNT(oi2.ItemCode)
  FROM       Orders         AS  o2
  INNER JOIN OrderItems     AS  oi2
        ON   oi2.OrderNo     =  o2.OrderNo
  WHERE      o2.OrderNo     <>  o.OrderNo
  AND        o2.OrderDate    =  o.OrderDate
  GROUP BY   o2.OrderNo);

SELECT a.GroupName, MAX(a.TheValue)
FROM QotD AS a
GROUP BY a.GroupName, a.TheValue

CREATE TABLE QotD 
  (GroupName varchar(20) NOT NULL,
   TheValue int NOT NULL,
   PRIMARY KEY (GroupName, TheValue)
  );
go
INSERT INTO QotD (GroupName, TheValue)
SELECT 'Group 1', 1 UNION ALL
SELECT 'Group 1', 2 UNION ALL
SELECT 'Group 1', 3 UNION ALL
SELECT 'Group 2', 1 UNION ALL
SELECT 'Group 2', 2 UNION ALL
SELECT 'Group 3', 1 UNION ALL
SELECT 'Group 3', 3 UNION ALL
SELECT 'Group 4', 2 UNION ALL
SELECT 'Group 4', 3 UNION ALL
SELECT 'Group 5', 1 UNION ALL
SELECT 'Group 6', 2 UNION ALL
SELECT 'Group 7', 3;
go
SELECT   a.GroupName --, MAX(a.TheValue)
FROM     QotD AS a
GROUP BY a.GroupName
HAVING EXISTS (SELECT *
               FROM   QotD AS b
               WHERE  b.TheValue > MAX(a.TheValue));
go
DROP TABLE QotD;
go

CREATE TABLE Orders(OrderNo INT,OrderDate DATETIME,CustomerNo INT)
CREATE TABLE OrderItems(OrderNo INT,Amount INT, ItemCode VARCHAR(10))
	
INSERT Orders
VALUES(100,'9-8-10',1),(101,'9-8-10',2),(102,'9-8-10',3)

INSERT OrderItems
VALUES(100,1,'Bike'),(100,2,'Tire'),(101,2,'Spokes'),(102,3,'Pedal')

DECLARE @CustomerNo AS INT = 1

SELECT       o.OrderNo,         o.OrderDate,
             SUM(oi.Amount) AS  TotalOrderAmount
FROM         Orders         AS  o
INNER JOIN   OrderItems     AS  oi
      ON     oi.OrderNo      =  o.OrderNo
WHERE        o.CustomerNo    =  @CustomerNo
GROUP BY     o.OrderNo,         o.OrderDate
HAVING NOT EXISTS
 (SELECT     *
  FROM       Orders         AS  o2
  INNER JOIN OrderItems     AS  oi2
        ON   oi2.OrderNo     =  o2.OrderNo
  WHERE      o2.OrderNo     <>  o.OrderNo
  AND        o2.OrderDate    =  o.OrderDate
  GROUP BY   o2.OrderNo
  HAVING     COUNT(oi2.ItemCode) = COUNT(oi.ItemCode)); -- Changed the <> to =
  
SELECT       o.OrderNo,         o.OrderDate,
             SUM(oi.Amount) AS  TotalOrderAmount
FROM         Orders         AS  o
INNER JOIN   OrderItems     AS  oi
      ON     oi.OrderNo      =  o.OrderNo
WHERE        o.CustomerNo    =  @CustomerNo
GROUP BY     o.OrderNo,         o.OrderDate
  HAVING       COUNT(oi.ItemCode) <> ALL
 (SELECT     COUNT(oi2.ItemCode)
  FROM       Orders         AS  o2
  INNER JOIN OrderItems     AS  oi2
        ON   oi2.OrderNo     =  o2.OrderNo
  WHERE      o2.OrderNo     <>  o.OrderNo
  AND        o2.OrderDate    =  o.OrderDate
  GROUP BY   o2.OrderNo);
  
DROP TABLE Orders
DROP TABLE OrderItems