SQL Server中order by 字段*1什么意思？sql如下

SELECT * FROM ( 
SELECT TBL.SKU AS SKU ,
LTRIM(S.SYOHINNAME) AS SYOHINNAME, 
TBL.BAIKA AS BAIKA, 
SUM(TBL.SURYO) AS SURYO 
FROM 
( SELECT REPLACE(LTRIM(REPLACE(LEFT(LTRIM(G.SKU),8), '0', ' ')), ' ', '0') AS SKU , 
G.BAIKA AS BAIKA, 
G.SURYO AS SURYO 
FROM GENDAT G
WHERE UPPER(LTRIM(RTRIM(G.AREA))) <> 'Z' 
) TBL 
LEFT OUTER JOIN SYOHINM S ON LTRIM(S.SKU) = TBL.SKU 
GROUP BY TBL.SKU,LTRIM(S.SYOHINNAME),TBL.BAIKA 
) AS TBL 
ORDER BY sku*1

按照第一列排序。。。。。

你看一下表结构，别名为sku的这个字段在表结构是字符串类型的，sku1，就是数字类型的排序；比如100,1000,200,500在数据表中，如果是字符串类型。这几个排序，就是100,1000,200,500；如果你加了1，那么最终的排序就是100,200,500,1000