新人来问，字符串里面是SQL语句，在字符串前加@时表示？？？？
例如：
string FindListSql = @" SELECT * FROM S_SYS_UNIVERSITY"

string InsertSql = @"INSERT INTO S_SYS_UNIVERSITY(
                ID
                , PARENTID
                , NAME
                , ADDRESS
                , WEBSITEURL
                , FAX
                , TEL
                , EMAIL
                , REMARK
                , ENABLED
                , ORDERNUMBER
                , ISDELETED
                , CREATEUSER
                , CREATEDATE
                , CREATETIME
                , MODIFYUSER
                , MODIFYDATE
                , MODIFYTIME
            ) VALUES (
                : ID
                , :PARENTID
                , :NAME
                , :ADDRESS
                , :WEBSITEURL
                , :FAX
                , :TEL
                , :EMAIL
                , :REMARK
                , :ENABLED
                , :ORDERNUMBER
                , :ISDELETED
                , :CREATEUSER
     &nbs