Alias cann't be used in the SELECT / WHERE statement

SELECT CaseNo,InCharge,XprCompany1,XprCompany2,XprCompany1+XprCompany2 'xpr' FROM ut_ForeignXpr
WHERE Xpr='DHLTNT'

錯誤訊息：無效的資料行名稱

http://msdn.microsoft.com/zh-tw/library/ms189499.aspx

SELECT 陳述式的邏輯處理順序
01. FROM
02. ON
03. JOIN
04. WHERE
05. GROUP BY
06. WITH CUBE 或 WITH ROLLUP
07. HAVING
08. SELECT
09. DISTINCT
10. ORDER BY
11. TOP