create row number in sql

1SELECT t.A, t.B, t.C, ROW_NUMBER() OVER (ORDER BY t.A) as newId
2  FROM dbo.tableZ AS t
3  ORDER BY t.A;

1-- Uses AdventureWorks  
2  
3SELECT ROW_NUMBER() OVER(ORDER BY SUM(SalesAmountQuota) DESC) 
4    AS RowNumber,  
5    FirstName, LastName,   
6    CONVERT(varchar(13), SUM(SalesAmountQuota),1) AS SalesQuota   
7FROM dbo.DimEmployee AS e  
8INNER JOIN dbo.FactSalesQuota AS sq  
9    ON e.EmployeeKey = sq.EmployeeKey  
10WHERE e.SalesPersonFlag = 1  
11GROUP BY LastName, FirstName;  
12

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