將以前寫的SQL2分查找法通用分頁存儲過程算法改成.net類實現

2019-11-18 16:41:43

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using System;

namespace CountryPark.DAL
...{
    /**//**//**//// <summary>
    /// PageList 的摘要說明。
    /// </summary>
    public sealed class PageList
    ...{
        static PageList()
        ...{
        }

        /**//**//**//// <summary>
        /// 分頁查詢數據記錄總數獲取
        /// </summary>
        /// <param name="_tbName">----要顯示的表或多個表的連接</param>
        /// <param name="_ID">----主表的主鍵</param>
        /// <param name="_strCondition">----查詢條件,不需where</param>
        /// <param name="_Dist">----是否添加查詢字段的 DISTINCT 默認0不添加/1添加</param>
        /// <returns></returns>
        public static string getPageListCounts(string _tbName, string _ID, string _strCondition, int _Dist)
        ...{
            //---存放取得查詢結果總數的查詢語句
            //---對含有DISTINCT的查詢進行SQL構造
            //---對含有DISTINCT的總數查詢進行SQL構造
            string strTmp="", SqlSelect="", SqlCounts="";

            if (_Dist == 0)
            ...{
                SqlSelect = "SELECT ";
                SqlCounts = "COUNT(*)";
            }
            else
            ...{
                SqlSelect = "SELECT DISTINCT ";
                SqlCounts = "COUNT(DISTINCT "+ _ID +")";
            }
            if (_strCondition == string.Empty)
            ...{
                strTmp = SqlSelect +" @Counts="+ SqlCounts +" FROM "+ _tbName;
            }
            else
            ...{
                strTmp = SqlSelect +" @Counts="+ SqlCounts +" FROM "+ " WHERE (1=1) "+ _strCondition;
            }
            return strTmp;
        }

        /**//**//**//// <summary>
        /// 獲取分頁數據查詢SQL
        /// </summary>
        /// <param name="_tbName">----要顯示的表或多個表的連接</param>
        /// <param name="_fldName">----要顯示的字段列表</param>
        /// <param name="_PageSize">----每頁顯示的記錄個數</param>
        /// <param name="_Page">----要顯示那一頁的記錄</param>
        /// <param name="_PageCount">----查詢結果分頁后的總頁數</param>
        /// <param name="_Counts">----查詢到的記錄數</param>
        /// <param name="_fldSort">----排序字段列表或條件(如果是多字段排列Sort指代最后一個排序字段的排列順序(最后一個排序字段不加排序標記)--程序傳參如：' SortA Asc,SortB Desc,SortC ')</param>
        /// <param name="_Sort">----排序方法，0為升序，1為降序</param>
        /// <param name="_strCondition">----查詢條件,不需where</param>
        /// <param name="_ID">----主表的主鍵</param>
        /// <param name="_Dist">----是否添加查詢字段的 DISTINCT 默認0不添加/1添加</param>
        /// <returns></returns>
        public static string getPageListSql(string _tbName, string _fldName, int _PageSize, int _Page, out int _PageCount, int _Counts, string _fldSort, int _Sort, string _strCondition, string _ID, int _Dist)
        ...{
            string strTmp=""; //---strTmp用于返回的SQL語句
            string SqlSelect="", strSortType="", strfsortType="";

            if (_Dist == 0)
            ...{
                SqlSelect = "SELECT ";
            }
            else
            ...{
                SqlSelect = "SELECT DISTINCT ";
            }

            if (_Sort == 0)
            ...{
                strFSortType = " ASC";
                strSortType = " DESC";
            }
            else
            ...{
                strFSortType = " DESC";
                strSortType = " ASC";
            }

//            ----取得查詢結果總數量-----
            int tmpCounts = 1;
            if (_Counts != 0)
            ...{
                tmpCounts = _Counts;
            }
//          --取得分頁總數
            _PageCount = (tmpCounts + _PageSize - 1)/_PageSize;
            //    /**//**當前頁大于總頁數取最后一頁**/
            if (_Page > _PageCount)
            ...{
                _Page = _PageCount;
            }
            if (_Page <= 0)
            ...{
                _Page = 1;
            }
//          --/*-----數據分頁2分處理-------*/
            int pageIndex = tmpCounts/_PageSize;
            int lastCount = tmpCounts%_PageSize;
            if (lastCount > 0)
            ...{
                pageIndex = pageIndex + 1;
            }
            else
            ...{
                lastCount = _PageSize;
            }
            if (_strCondition == string.Empty) // --沒有設置顯示條件
            ...{
                if (pageIndex < 2 || _Page <= (pageIndex/2 + pageIndex%2)) //--前半部分數據處理
                ...{
                    if (_Page == 1)
                    ...{
                        strTmp = SqlSelect +" TOP "+ _PageSize +" "+ _fldName +" FROM "+ _tbName +" ORDER BY "+ _fldSort +" "+ strFSortType;
                    }
                    else
                    ...{
                        strTmp = SqlSelect +" TOP "+ _PageSize +" "+ _fldName +" FROM "+ _tbName +" WHERE "+ _ID +" <(SELECT MIN("+ _ID +") FROM ("+ SqlSelect +" TOP "+ _PageSize*(_Page-1) +" "+ _ID +" FROM "+ _tbName +
                            " ORDER BY "+ _fldSort +" "+ strFSortType +") AS TBMinID) ORDER BY "+ _fldSort +" "+ strFSortType;
                    }
                }
                else
                ...{
                    _Page = pageIndex - _Page + 1; //后半部分數據處理
                    if (_Page <= 1) //--最后一頁數據顯示
                    ...{
                        strTmp = SqlSelect +" * FROM ("+ SqlSelect +" TOP "+ lastCount +" "+ _fldName +" FROM "+ _tbName +" ORDER BY "+ _fldSort +" "+ strSortType +") AS TempTB"+ " ORDER BY "+ _fldSort +" "+ strFSortType;
                    }
                    else
                    ...{
                        strTmp = SqlSelect +" * FROM ("+ SqlSelect +" TOP "+ _PageSize +" "+ _fldName +" FROM "+ _tbName +
                            " WHERE "+ _ID +" >(SELECT MAX("+ _ID +") FROM("+ SqlSelect +" TOP "+ (_PageSize*(_Page-2)+lastCount) +" "+ _ID +" FROM "+ _tbName +
                            " ORDER BY "+ _fldSort +" "+ strSortType +") AS TBMaxID) ORDER BY "+ _fldSort +" "+ strSortType +") AS TempTB ORDER BY "+ _fldSort +" "+ strFSortType;
                    }
                }
            }
            else // --有查詢條件
            ...{
                if (pageIndex < 2 || _Page <=(pageIndex/2 + pageIndex%2))//--前半部分數據處理
                ...{
                    if (_Page == 1)
                    ...{
                        strTmp = SqlSelect +" TOP "+ _PageSize +" "+ _fldName +" FROM "+ _tbName +"WHERE 1=1 "+ _strCondition +" ORDER BY "+ _fldSort +" "+ strFSortType;
                    }
                    else
                    ...{
                        strTmp = SqlSelect +" TOP "+ _PageSize +" "+ _fldName +" FROM "+ _tbName +
                            " WHERE "+ _ID +" <(SELECT MIN("+ _ID +") FROM ("+ SqlSelect +" TOP "+ (_PageSize*(_Page-1)) +" "+ _ID +" FROM " +_tbName +
                            " WHERE 1=1 "+ _strCondition +" ORDER BY "+ _fldSort +" "+ strFSortType +") AS TBMaxID) "+ _strCondition +
                            " ORDER BY "+ _fldSort +" "+ strFSortType;
                    }
                }
                else //--后半部分數據處理
                ...{
                    _Page = pageIndex-_Page+1;
                    if (_Page <= 1) //--最后一頁數據顯示
                    ...{
                        strTmp = SqlSelect +" * FROM ("+ SqlSelect +" TOP "+ lastCount +" "+ _fldName +" FROM "+ _tbName +
                            " WHERE 1=1 "+ _strCondition +" ORDER BY "+ _fldSort +" "+ strSortType +") AS TempTB ORDER BY "+ _fldSort +" "+ strFSortType;
                    }
                    else
                    ...{
                        strTmp = SqlSelect +" * FROM ("+ SqlSelect +" TOP "+ _PageSize +" "+ _fldName +" FROM "+ _tbName +
                            " WHERE "+ _ID +" >(SELECT MAX("+ _ID +") FROM("+ SqlSelect +" TOP "+ (_PageSize*(_Page-2)+ lastCount) +" "+ _ID +" FROM "+ _tbName +
                            " WHERE 1=1 "+ _strCondition +" ORDER BY "+ _fldSort +" "+ strSortType +") AS TBMaxID) "+ _strCondition +
                            " ORDER BY "+ _fldSort +" "+ strSortType +") AS TempTB ORDER BY "+ _fldSort +" "+ strFSortType;
                    }
                }
            }

            return strTmp;
        }
    }
}
--以上代碼是針對之前寫的TOP MAX模式的分頁存儲過程修改
--以上分頁算法對SQL SERVER 和 access同樣有效
參見:http://www.49028c.com/hertcloud/archive/2005/12/21/301327.html

//調用函數例子
public IList getParkDataList(string key, int curPage, out int pageCount, int pageSize, int Counts)
        ...{

            IList list = new ArrayList();

            string SECLECT_FIELD = "T_Park.ParkID, T_Park.ParkTitle, T_Park.ParkLetter, T_ParkArea.AreaName, T_ParkType.ParkTypeName ";
            string SECLECT_TABLE = "T_ParkType INNER JOIN (T_ParkArea INNER JOIN T_Park ON T_ParkArea.ParkAreaID = T_Park.ParkAreaID) ON T_ParkType.ParkTypeID = T_Park.ParkTypeID";
            string SECLECT_CONDITION = string.Empty;

            if (key != string.Empty)
            ...{
                SECLECT_CONDITION = " AND T_Park.ParkTitle like '%"+ key +"%'";
            }

            string SELECT_ID = "ParkID";
            string SELECT_FLDSORT = "ParkID";
            int SELECT_SORT = 1;
            int SELECT_DIST = 0;
            string SQL = PageList.getPageListSql(SECLECT_TABLE, SECLECT_FIELD, pageSize, curPage, out pageCount, Counts, SELECT_FLDSORT, SELECT_SORT, SECLECT_CONDITION, SELECT_ID, SELECT_DIST);
            //string strCondition;
            OleDb db = new OleDb();
            ParkBE park;
            using(OleDbDataReader dr = (OleDbDataReader)db.ExecuteReader(CommonFun.GetConnectionString(), CommandType.Text, SQL))
            ...{
                while (dr.Read())
                ...{
                    park = new ParkBE();
                    park.ParkID = Convert.ToInt32(dr[0]);
                    park.ParkTitle = dr[1].ToString();
                    park.ParkLetter = dr[2].ToString();
                    park.ParkAreaName = dr[3].ToString();
                    park.ParkTypeName = dr[4].ToString();
                    list.Add(park);
                }
            }
            return list;
        }
http://blog.csdn.net/todaywlq/archive/2007/01/29/1497418.aspx