帮忙看看这一段存储过程的代码，老是报错。
ELSE IF(@topnum> 0)
BEGIN
IF(@type> 0)

SELECT TOP (@topnum)
A.ArticleID,
A.ArticleTitle,
A.ArticleContent,
A.ArticleImg,
PublicDate,
ViewTimes,
A.ArticleType As TypeID,
B.TypeTxt
FROM ArticleInfo A
JOIN TypeInfo B
ON A.ArticleType=B.TypeID
AND A.ArticleType=@type
ORDER BY ArticleID DESC
END
Incorrect syntax near '( '.SELECT TOP (@topnum)指的是这一行

[解决办法]
TOP后只允许使用常数，不能使用变量。

可以使用动态SQL或SET ROWCOUNT
[解决办法]
delcare @sql varchar(300)
set @sql= 'SELECT TOP '+ (@topnum)+ '
A.ArticleID,
A.ArticleTitle,
A.ArticleContent,
A.ArticleImg,
PublicDate,
ViewTimes,
A.ArticleType As TypeID,
B.TypeTxt
FROM ArticleInfo A
JOIN TypeInfo B
ON A.ArticleType=B.TypeID
AND A.ArticleType=@type
ORDER BY ArticleID DESC '

exec (@sql)
[解决办法]
ELSE IF(@topnum> 0)
BEGIN
IF(@type> 0)

exec( 'SELECT TOP '+@topnum+ ' A.ArticleID,A.ArticleTitle,A.ArticleContent,A.ArticleImg,PublicDate,ViewTimes,A.ArticleType As TypeID,B.TypeTxt FROM ArticleInfo A JOIN TypeInfo B ON A.ArticleType=B.TypeID AND A.ArticleType= '+@type+ ' ORDER BY ArticleID DESC ')
END