跨数据库多表联合动态条件查询

一、控制器中方法

[HttpGet]
        public ActionResult Search()
        {
            ViewBag.HeadTitle = "搜索";
            ViewBag.MetaKey = ""123"";
            ViewBag.MetaDes = ""456"";

            string whereText = "";
            if (Security.HtmlHelper.GetQueryString("first", true) != string.Empty)
            {
                whereText += " and a.ParentId='" + StringFilter("first", true)+"'";
            }

            if (Security.HtmlHelper.GetQueryString("second", true) != string.Empty)
                whereText += " and a.categoryId='" + StringFilter("second",true)+"'";

            string valueStr = "";
            if (Security.HtmlHelper.GetQueryString("theme", true) != string.Empty)
                valueStr += StringFilter("theme", true) + ",";
            if (Security.HtmlHelper.GetQueryString("size", true) != string.Empty)
                valueStr += StringFilter("size", true) + ",";
            if (Security.HtmlHelper.GetQueryString("font", true) != string.Empty)
                valueStr += StringFilter("font", true) + ",";
            if (Security.HtmlHelper.GetQueryString("shape", true) != string.Empty)
                valueStr += StringFilter("shape", true) + ",";
            if (Security.HtmlHelper.GetQueryString("technique", true) != string.Empty)
                valueStr += StringFilter("technique", true) + ",";
            if (Security.HtmlHelper.GetQueryString("category", true) != string.Empty)
                valueStr += StringFilter("category", true) + ",";
            if (Security.HtmlHelper.GetQueryString("place", true) != string.Empty)
                valueStr += StringFilter("place", true) + ",";
            if (Security.HtmlHelper.GetQueryString("price", true) != string.Empty)
                valueStr += StringFilter("price", true) + ",";

            if (valueStr != "")
            {
                valueStr=valueStr.Substring(0, valueStr.Length - 1);
                whereText += " and f.valueId in("+valueStr+")";
            }

            if (Security.HtmlHelper.GetQueryString("searchKeys", true) != string.Empty)
                whereText += " and a.SaleTitle like '%'" + StringFilter("searchKes", true) + "'%' or a.SaleDes like '%'" + StringFilter("searchKes", true) + "'%' or a.SaleAuthor like '%'" + StringFilter("searchKes", true) + "'%' or a.KeyWords like '%'" + StringFilter("searchKes", true) + "'%' or g.valueProperty like '%'" + StringFilter("searchKes", true) + "'%'";

            int pageSize = 50;
            int pageIndex = HttpContext.Request.QueryString["pageIndex"].Toint(1);
            List<string> searchInfo = Search(pageIndex, pageSize, whereText, 1);

            if (Security.HtmlHelper.GetQueryString("sort", true) != string.Empty)
            {
                string sort = StringFilter("sort", true);
                switch (sort)
                {
                    case "1":    //综合即默认按照上架时间降序排列即按照id降序
                        searchInfo = Search(pageIndex, pageSize, whereText, 1);
                        break;
                    case"2":    //销量
                        searchInfo = Search(pageIndex, pageSize, whereText,0, "saleTotal");
                        break;
                    case "3":   //收藏
                        searchInfo = Search(pageIndex, pageSize, whereText,0, "favoritesTotal");
                        break;
                    case "4":   //价格升序
                        searchInfo = Search(pageIndex, pageSize, whereText,1);
                        break;
                    case "5":   //价格降序
                        searchInfo = Search(pageIndex, pageSize, whereText,2);
                        break;
                }
            }

            string jsonStr = searchInfo[0];
            ViewData["jsondata"] = jsonStr;
            
            int allCount = Utility.Toint(searchInfo[1], 0);
            ViewBag.AllCount = allCount;
            ViewBag.MaxPages = allCount % pageSize == 0 ? allCount / pageSize : (allCount / pageSize + 1).Toint(1);

            return View();
        }

        [NonAction]
        public List<string> Search(int pageIndex, int pageSize, string whereText, int orderByPrice, string orderBy = "SaleId")
        {
            BLL.Products searchInfoBLL = new BLL.Products();

            List<string> searchInfo = searchInfoBLL.GetSearchInfo(pageIndex, pageSize, whereText, orderByPrice,orderBy);
            return searchInfo;
        }

注：Security.HtmlHelper.GetQueryString(），StringFilter(）为自己封装的方法，用于过滤参数值

二、BLL层方法

using System;
using System.Web;
using System.Web.Caching;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.Common;
using System.Web.Script.Serialization;
using FotosayMall.Model;
using FotosayMall.Common;
using System.Text.RegularExpressions;
using System.IO;
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
using FotosayMall.MVC.Models;

namespace FotosayMall.BLL
{
    public class Products
    {

        private readonly DAL.Products dal = new DAL.Products();

        /// <summary>
        /// 分页查询，检索页数据
        /// </summary>
        /// <param name="pageIndex"></param>
        /// <param name="pageSize"></param>
        /// <param name="orderByPrice">价格排序：0默认，1升序，2降序</param>
        /// <returns></returns>
        public List<string> GetSearchInfo(int pageIndex, int pageSize, string whereText, int orderByPrice, string orderBy = "SaleId")
        { 
            DataSet searchInfoTables = dal.GetSearchInfo(pageIndex, pageSize, whereText);
            //总记录数
            int allCount = Utility.Toint(searchInfoTables.Tables[1].Rows[0]["rowsTotal"], 0);
            var searchInfo = from list in searchInfoTables.Tables[0].AsEnumerable().OrderByDescending(x => x.Table.Columns[orderBy])
                             select new SearchModel
                             {
                                 Url = "/home/products?saleId=" + list.Field<int>("SaleId"),
                                 Author = list.Field<string>("SaleAuthor"),
                                 PhotoFileName = list.Field<string>("PhotoFileName"),
                                 PhotoFilePathFlag = list.Field<int>("PhotoFilePathFlag"),
                                 Province = list.Field<string>("Place").Split(' ').First(),
                                 SalePrice = list.Field<decimal>("SalePrice"),
                                 UsingPrice = list.Field<decimal>("usingPrice"),
                                 Title = list.Field<string>("SaleTitle").Length > 30 ? list.Field<string>("SaleTitle").Substring(0, 30) : list.Field<string>("SaleTitle"),
                                 Year = list.Field<DateTime>("BuildTime").ToString("yyyy") == "1900" ? "" : list.Field<DateTime>("BuildTime").ToString("yyyy年")
                             };

            if (orderByPrice==2)
                searchInfo = searchInfo.OrderByDescending(x => x.Price);
            else if (orderByPrice == 1)
                searchInfo = searchInfo.OrderBy(x => x.Price);

            string jsonStr = JsonConvert.SerializeObject(searchInfo);
            List<string> dataList = new List<string>();
            dataList.Add(jsonStr);
            dataList.Add(allCount.ToString());
            return dataList;
        }
    }
}

注：注意观察由DataTable转换为可枚举的可用于Linq查询的方法方式。

DAL

/// <summary>
        /// 获取检索页数据
        /// </summary>
        /// <param name="pageIndex"></param>
        /// <param name="pageSize"></param>
        /// <returns></returns>
        public DataSet GetSearchInfo(int pageIndex, int pageSize, string whereText)
        {
            StringBuilder sqlText = new StringBuilder();
            sqlText.Append("select * from (");
            sqlText.Append("select a.SaleId,a.PhotoId,SaleTitle,SaleAuthor,a.Status,a.categoryId,c.UserID,c.UserName,b.PhotoFilePathFlag,b.PhotoFileName,coalesce(e.BuildTime,0) BuildTime,c.Place,coalesce(d.usingPrice,0) usingPrice,coalesce(e.SalePrice,0) SalePrice,h.saleTotal,h.favoritesTotal,row_number() over(order by a.saleId) rowsNum ");
            sqlText.Append("from fotosay..Photo_Sale a join fotosay..Photo_Basic b on a.PhotoId = b.PhotoID ");
            sqlText.Append("join fotosay..System_AccountsDescription c on b.UserID = c.UserID ");
            sqlText.Append("left join fotosay..Photo_Sale_Picture d on a.SaleId = d.SaleId ");
            sqlText.Append("left join fotosay..Photo_Sale_Tangible e on a.saleId = e.saleId ");
            sqlText.Append("join FotosayMall..Fotomall_Product_Relation f on f.saleId = a.SaleId ");
            sqlText.Append("join FotosayMall..Fotomall_Product_PropertyValue g on g.categoryId = a.categoryId and g.valueId = f.valueId and g.propertyId = f.propertyId ");
            sqlText.Append("join fotosay..Photo_Sale_Property h on a.saleId = h.saleId ");
            sqlText.Append("where a.Status=1 " + whereText + " "); 
            sqlText.Append("group by a.SaleId,a.PhotoId,SaleTitle,SaleAuthor,a.Status,a.categoryId,c.UserID,c.UserName,b.PhotoFilePathFlag,b.PhotoFileName,e.BuildTime,c.Place,usingPrice,SalePrice,h.saleTotal,h.favoritesTotal ");
            sqlText.Append(") t where rowsNum between @PageSize*(@PageIndex-1)+1 and @PageSize*@PageIndex;");
            sqlText.Append("select count(distinct a.saleId) rowsTotal  from fotosay..Photo_Sale a join (select b1.PhotoFilePathFlag,b1.PhotoFileName,b1.UserID,b1.PhotoID from fotosay..Photo_Basic b1 union select b2.PhotoFilePathFlag,b2.PhotoFileName,b2.UserID,b2.PhotoID from fotosay..Photo_Basic_History b2 ) b on a.PhotoId = b.PhotoID join fotosay..System_AccountsDescription c on b.UserID = c.UserID left join fotosay..Photo_Sale_Picture d on a.SaleId = d.SaleId left join fotosay..Photo_Sale_Tangible e on a.saleId = e.saleId join FotosayMall..Fotomall_Product_Relation f on f.saleId = a.SaleId join FotosayMall..Fotomall_Product_PropertyValue g on g.categoryId = a.categoryId and g.valueId = f.valueId and g.propertyId = f.propertyId join fotosay..Photo_Sale_Property h on a.saleId = h.saleId where a.Status=1 " + whereText + ";");

            DbParameter[] parameters = { 
                                        Fotosay.CreateInDbParameter("@PageIndex", DbType.Int32,pageIndex),
                                        Fotosay.CreateInDbParameter("@PageSize", DbType.Int32,pageSize)
                                       };

            DataSet searchInfoList = Fotosay.ExecuteQuery(CommandType.Text, sqlText.ToString(), parameters);

            //记录条数不够一整页,则查历史库
            if (searchInfoList.Tables[0].Rows.Count < pageSize)
            {
                string sql = "select top(1) a.saleId  from fotosay..Photo_Sale a join fotosay..Photo_Basic_History b on a.PhotoId = b.PhotoID join fotosay..System_AccountsDescription c on b.UserID = c.UserID left join fotosay..Photo_Sale_Picture d on a.SaleId = d.SaleId left join fotosay..Photo_Sale_Tangible e on a.saleId = e.saleId join FotosayMall..Fotomall_Product_Relation f on f.saleId = a.SaleId join FotosayMall..Fotomall_Product_PropertyValue g on g.categoryId = a.categoryId and g.valueId = f.valueId and g.propertyId = f.propertyId join fotosay..Photo_Sale_Property h on a.saleId = h.saleId where a.Status=1 " + whereText + ";";

                DataSet ds = Fotosay.ExecuteQuery(CommandType.Text, sql.ToString(), parameters);

                if (ds != null && ds.Tables[0].Rows.Count > 0)
                {
                    StringBuilder sqlTextMore = new StringBuilder();
                    sqlTextMore.Append("select * from (");
                    sqlTextMore.Append("select a.SaleId,a.PhotoId,SaleTitle,SaleAuthor,a.Status,a.categoryId,c.UserID,c.UserName,b.PhotoFilePathFlag,b.PhotoFileName,coalesce(e.BuildTime,0) BuildTime,c.Place,coalesce(d.usingPrice,0) usingPrice,coalesce(e.SalePrice,0) SalePrice,h.saleTotal,h.favoritesTotal,row_number() over(order by a.saleId) rowsNum ");
                    sqlTextMore.Append("from fotosay..Photo_Sale a ");
                    sqlTextMore.Append("join (select b1.PhotoFilePathFlag,b1.PhotoFileName,b1.UserID,b1.PhotoID from fotosay..Photo_Basic b1 union select b2.PhotoFilePathFlag,b2.PhotoFileName,b2.UserID,b2.PhotoID from fotosay..Photo_Basic_History b2 ) b on a.PhotoId = b.PhotoID join fotosay..System_AccountsDescription c on b.UserID = c.UserID ");
                    sqlTextMore.Append("left join fotosay..Photo_Sale_Picture d on a.SaleId = d.SaleId ");
                    sqlTextMore.Append("left join fotosay..Photo_Sale_Tangible e on a.saleId = e.saleId ");
                    sqlTextMore.Append("join FotosayMall..Fotomall_Product_Relation f on f.saleId = a.SaleId ");
                    sqlTextMore.Append("join FotosayMall..Fotomall_Product_PropertyValue g on g.categoryId = a.categoryId and g.valueId = f.valueId and g.propertyId = f.propertyId ");
                    sqlTextMore.Append("join fotosay..Photo_Sale_Property h on a.saleId = h.saleId ");
                    sqlTextMore.Append("where a.Status=1 " + whereText + " ");
                    sqlTextMore.Append("group by a.SaleId,a.PhotoId,SaleTitle,SaleAuthor,a.Status,a.categoryId,c.UserID,c.UserName,b.PhotoFilePathFlag,b.PhotoFileName,e.BuildTime,c.Place,usingPrice,SalePrice,h.saleTotal,h.favoritesTotal");
                    sqlTextMore.Append(") t where rowsNum between @PageSize*(@PageIndex-1)+1 and @PageSize*@PageIndex;");
                    sqlTextMore.Append("select count(distinct a.saleId) rowsTotal  from fotosay..Photo_Sale a join (select b1.PhotoFilePathFlag,b1.PhotoFileName,b1.UserID,b1.PhotoID from fotosay..Photo_Basic b1 union select b2.PhotoFilePathFlag,b2.PhotoFileName,b2.UserID,b2.PhotoID from fotosay..Photo_Basic_History b2 ) b on a.PhotoId = b.PhotoID join fotosay..System_AccountsDescription c on b.UserID = c.UserID left join fotosay..Photo_Sale_Picture d on a.SaleId = d.SaleId left join fotosay..Photo_Sale_Tangible e on a.saleId = e.saleId join FotosayMall..Fotomall_Product_Relation f on f.saleId = a.SaleId join FotosayMall..Fotomall_Product_PropertyValue g on g.categoryId = a.categoryId and g.valueId = f.valueId and g.propertyId = f.propertyId join fotosay..Photo_Sale_Property h on a.saleId = h.saleId where a.Status=1 " + whereText + ";");

                    searchInfoList = Fotosay.ExecuteQuery(CommandType.Text, sqlTextMore.ToString(), parameters);
                }
            }

            return searchInfoList;
        }

注：注意其中使用的跨数据库查询的方式和union的一种使用方式

Model

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Web;

namespace FotosayMall.MVC.Models
{
    public class SearchModel
    {
        /// <summary>
        /// 原始图片文件夹(用于url地址)
        /// </summary>
        private const string OriginImagesUrlFolder = "userimages/photos_origin";

        /// <summary>
        /// 购买页链接
        /// </summary>
        public string Url { get; set; }

        /// <summary>
        /// 所属域名(1为fotosay，2为img，3为img1)
        /// </summary>
        public int PhotoFilePathFlag { get; set; }

        /// <summary>
        /// 图片名称
        /// </summary>
        public string PhotoFileName { get; set; }

        /// <summary>
        /// 商品名称
        /// </summary>
        public string Title { get; set; }

        /// <summary>
        /// 作者所在省份
        /// </summary>
        public string Province { get; set; }

        /// <summary>
        /// 作者
        /// </summary>
        public string Author { get; set; }

        /// <summary>
        /// 创作年份
        /// </summary>
        public string Year { get; set; }

        /// <summary>
        /// 图片：单次价格
        /// </summary>
        public decimal UsingPrice { get; set; }

        /// <summary>
        /// 实物：定价
        /// </summary>
        public decimal SalePrice { get; set; }

        /// <summary>
        /// 售价
        /// </summary>
        public string Price
        {
            get
            {
                if (this.UsingPrice > 0)
                    return this.UsingPrice.ToString();
                else if (this.SalePrice > 0)
                    return this.SalePrice.ToString();
                else
                    return "议价";
            }
        }

        /// <summary>
        /// 
        /// </summary>
        private string MasterSite
        {
            get { return ConfigurationManager.AppSettings["masterSite"].ToString(); }
        }

        /// <summary>
        /// 图片完整路径
        /// </summary>
        public string Img
        {
            get
            {
                return MasterSite + "/" + OriginImagesUrlFolder + this.PhotoFileName + "b.jpg";
            }
        }
    }
}