在界面层中的代码：
List<SearchModel> ss = new List<SearchModel>(); if (!string.IsNullOrEmpty(Request.Form["txtName"]))//如果用户在名字框中输入了文字 { SearchModel model = new SearchModel(); model.Name = "BookName";//要操作的字段为书名 model.Value = Request.Form["txtName"];//对应的值为用户输入的文字 model.Action = Action.Like;//操作为like ss.Add(model); }//以下类似 if (!string.IsNullOrEmpty(Request.Form["txtAuthor"])) { SearchModel model = new SearchModel(); model.Name = "Author"; model.Value = Request.Form["txtAuthor"]; model.Action = Action.Like; ss.Add(model); } if (!string.IsNullOrEmpty(Request.Form["categoryId"])) { SearchModel model = new SearchModel(); model.Name = "CategoryId"; model.Value = Request.Form["categoryId"]; model.Action = Action.Equart; ss.Add(model); } if (!string.IsNullOrEmpty(Request.Form["publisherId"])) { SearchModel model = new SearchModel(); model.Name = "PublisherId"; model.Value = Request.Form["publisherId"]; model.Action = Action.Equart; ss.Add(model); } if (!string.IsNullOrEmpty(Request.Form["txtISBN"])) { SearchModel model = new SearchModel(); model.Name = "ISBN"; model.Value = Request.Form["txtISBN"]; model.Action = Action.Like; ss.Add(model); } if (!string.IsNullOrEmpty(Request.Form["isDiscount"])) { SearchModel model = new SearchModel(); model.Name = "Discount"; model.Value = "1"; model.Action = Action.Equart; ss.Add(model); } List<T_Books> books = searchBll.Searc(ss);//这里调用Bll进行操作 |
Bll就先不说，主要是Dal层的sql拼接
public List<T_Books> Search(List<SearchModel> ss)//接收传进来的条件模型类集合，并对其进行遍历 { string sql = "select * from T_Books where IsDelete=0 and ";//开始拼接sql语句 for (int i = 0; i < ss.Count; i++) { if (ss[i].Action == Action.Like) { sql += ss[i].Name + " like '%" + ss[i].Value + "%'"; } if (ss[i].Action == Action.Equart) { sql += ss[i].Name + " = " + ss[i].Value; } if (ss[i].Action == Action.Greatthan) { sql += ss[i].Name + " > " + ss[i].Value; } if (ss[i].Action == Action.Lessthan) { sql += ss[i].Name + " < " + ss[i].Value; } if (i != ss.Count - 1) { sql += " and "; } } List<T_Books> list = new List<T_Books>(); DataTable table = SqlHelper.ExecuteDataTable(sql, CommandType.Text);//将拼接好的sql语句传入，开始查询数据库 foreach (DataRow row in table.Rows) { T_Books book = GetModelByDataRow.GetBooks(row); list.Add(book); } return list;//返回符合条件的图书集合，完成 } |
假设用户输入下图的条件：
最后贴上测试拼接的sql语句，如下
select * from T_Books where IsDelete=0 and BookName like '%C++%' and Author like '%JChubby%' and CategoryId = 15 and PublisherId = 16 and ISBN like '%1111%' and Discount = 1
大功告成~！
