sql执行顺序

SELECT  DrawID,MAX(CASE PropertyTextID
              WHEN 21 THEN Text
              ELSE NULL
            END) AS uName ,
        MAX(CASE PropertyTextID
              WHEN 10 THEN Text
              ELSE NULL
            END) AS uPositon ,
        MAX(CASE PropertyTextID
              WHEN 5 THEN Text
              ELSE NULL
            END) AS uTel
FROM    GaituApp.dbo.TemplateDrawText
GROUP BY DrawID