sql中的分頁實現

1.兩種方式

  1.1：row_number() over()函數

  1.2：OFFSET ....FETCH 

        OFFSET { integer_constant | offset_row_count_expression } { ROW | ROWS }

        指定在從查詢表達式中開始返回行之前，將跳過的行數。OFFSET 子句的參數可以是大於或等於零的整數或表達式。ROW 和 ROWS 可以互換使用。

        FETCH { FIRST|NEXT } <行計數表達式> { ROW|ROWS } ONLY

      指定在處理 OFFSET 子句後，將返回的行數。FETCH 子句的參數可以是大於或等於 1 的整數或表達式。ROW 和 ROWS 可以互換使用。同樣，FIRST 和 NEXT 可以互換使用。

每頁10條，查詢第10頁的數據

select * from (select row_number() over(order by U_sortNo) as Rm,* from A01 where u_areacode='130000') as t where 100<Rm and Rm<=110

SELECT A0100,COUNT(1) OVER() AS total
FROM A01
where u_areacode='130000'
ORDER BY U_sortNo
OFFSET 100 ROWS FETCH NEXT 10 ROWS ONLY

說明跳過100行不包括第100條數據，並查出來之後的10的數據，也就是101-110中的十條數據

        /// 分頁
        /// </summary>
        /// <param name="pageIndex">獲取當前頁碼預設為1</param>
        /// <param name="pageSize">獲取每頁顯示多少條記錄</param>
        public string GetUserList(int pageIndex, int pageSize,string orderField, string orderType)
        {
            int count;
            string sql = @"select a.*,b.Title,b.Content from Power_user a
left join Knowledge b on a.ID = b.CreateUserID";
            string strsql = string.Format("select * from ({0}) T_TT  where 1=1 ", sql);
            StringBuilder stringBuilder = new StringBuilder();
            int num = (pageIndex-1) * pageSize;
            int num2 = pageIndex * pageSize;
            string str;
            if (!string.IsNullOrEmpty(orderField))
            {
                str = "Order By " + orderField + " " + orderType;
            }
            else
            {
                str = "order by (select 0)";
            }
            stringBuilder.Append("Select * From (Select ROW_NUMBER() Over (" + str + ")");
            stringBuilder.Append(string.Concat(new object[]
            {
                " As rowNum, * From (",
                strsql,
                ") As T ) As N Where rowNum > ",
                num,
                " And rowNum <= ",
                num2
            }));
            count = System.Convert.ToInt32(SqlHelper.ExecuteScalar(SqlHelper.ConnectionString, CommandType.Text, "Select Count(1) From (" + strsql + ") As t", null)); ;
            DataTable dt = SqlHelper.ExecuteDataTable(SqlHelper.ConnectionString, CommandType.Text, stringBuilder.ToString(), null);
            string Json = JsonConvert.SerializeObject(dt);
             List<Power_User> userModel = SqlHelper.ExecuteClass<Power_User>(SqlHelper.ConnectionString, strsql, null);
            //string b = JsonConvert.SerializeObject(userModel);
            return Json;
        }