如何在CASE表达式后插入T-SQL代码？

SELECT 
    CustomerID, 
    FirstName, 
    LastName, 
    CASE 
        WHEN TotalOrders > 10 THEN '高订单量'
        WHEN TotalOrders BETWEEN 5 AND 10 THEN '中等订单量'
        ELSE '低订单量'
    END AS OrderCategory
FROM Customers;

SELECT 
    CustomerID, 
    FirstName, 
    LastName, 
    CASE 
        WHEN TotalOrders > 10 THEN (SELECT SomeColumn FROM AnotherTable WHERE Condition)
        ELSE '低订单量'
    END AS SomeResult
FROM Customers;

WITH OrderCategories AS (
    SELECT CustomerID, 
           CASE 
               WHEN TotalOrders > 10 THEN '高订单量'
               WHEN TotalOrders BETWEEN 5 AND 10 THEN '中等订单量'
               ELSE '低订单量'
           END AS OrderCategory
    FROM Customers
)
SELECT * FROM OrderCategories WHERE OrderCategory = '高订单量';