tsql row number

1SELECT 
2   ROW_NUMBER() OVER (
3 ORDER BY first_name
4   ) row_num,
5   first_name, 
6   last_name, 
7   city
8FROM 
9   sales.customers;
10

1
2        
3            
4        
5     SELECT 
6   ROW_NUMBER() OVER (
7	ORDER BY first_name
8   ) row_num,
9   first_name, 
10   last_name, 
11   city
12FROM 
13   sales.customers;

1USE AdventureWorks2012;  
2GO  
3WITH OrderedOrders AS  
4(  
5    SELECT SalesOrderID, OrderDate,  
6    ROW_NUMBER() OVER (ORDER BY OrderDate) AS RowNumber  
7    FROM Sales.SalesOrderHeader   
8)   
9SELECT SalesOrderID, OrderDate, RowNumber    
10FROM OrderedOrders   
11WHERE RowNumber BETWEEN 50 AND 60;  
12