/// <summary>
/// 将传入SQL语句按PageInfo对象生成Select分页语句。并填充相关信息到PageInfo对象。
/// 注：1 SQL必须是Select语句。
/// 2 必须有Order By子句。
/// </summary>
private static string BuildSelectWithPage(string sql, PageInfo pageinfo, SqlParameter[] cmdParam)
{
int PageSize = pageinfo.PageSize;
int PageNum = pageinfo.CurrentPage;
string OrderBy = sql.Substring(sql.ToLower().IndexOf("order by"));
string SelectSql = sql.Substring(0, sql.ToLower().IndexOf("order by"));
string sb = "select * from ( select row_number() over ({0}) as rowid,* from ({1}) t )t where t.rowid>={2} and t.rowid<={3}";
string ret = string.Format(sb.ToString(), OrderBy, SelectSql, PageSize * (PageNum - 1) + 1, PageNum * PageSize);
//计算分页信息。
string SelectCountSql = SelectSql.Replace("*", "count(*)");
pageinfo.TotalRecords = (int)DbHelperSQL.ExecuteSqlScalar(SelectCountSql, cmdParam);
pageinfo.CalculatePages();
return(ret);
}