如何完成一個小型工程報價數據庫系統

今天小編給大家分享一下如何完成一個小型工程報價數據庫系統的相關知識點，內容詳細，邏輯清晰，相信大部分人都還太了解這方面的知識，所以分享這篇文章給大家參考一下，希望大家閱讀完這篇文章后有所收獲，下面我們一起來了解一下吧。

功能很簡單，完成基本的增刪改查

• 搭建項目三層結構

• 界面的設計以及美化

• 分層代碼的設計與實現

1.模型層：由于表設計時存在主外鍵關系，故把表映射成對象時添加一個外鍵對象來保存外鍵那張表的相關數據。

// 外鍵實體              private Product _product;              private Project _project;               public Project _Project              {                  get { return _project; }                  set { _project = value; }              }               public Product _Product              {                  get { return _product; }                  set { _product = value; }              }

2.數據訪問層：把數據封裝成Model對象的各層之間傳遞。

我個人不喜歡三層之間傳遞DataSet數據集，我的理解是盡量不在BLL層出現DataSet，所以我在DAL層把所有獲取的數據封裝成IEnumerable集合，然后返回。

protected IEnumerable<ProjectItem> ToModelsByFK(SqlDataReader reader)           {               var list = new List<ProjectItem>();               while (reader.Read())               {                   list.Add(ToModelByFK(reader));               }               return list;           }

public ProjectItem ToModelByFK(SqlDataReader reader)           {               ProjectItem projectItem = new ProjectItem();               projectItem._Product = new Product();               projectItem._Project = new Project();               projectItem.ID = (int)ToModelValue(reader, "ID");               projectItem._Product.ID = (int)ToModelValue(reader, "ProductID");               projectItem._Project.ID = (int)ToModelValue(reader,"projectID");               projectItem._Product.Manufacturer = ToModelValue(reader, "Manufacturer").ToString();               projectItem._Product.Parameters = ToModelValue(reader, "Parameters").ToString();               projectItem._Product.Price = decimal.Parse( ToModelValue(reader, "Price").ToString());               projectItem._Product.ProductName = ToModelValue(reader, "ProductName").ToString();               projectItem._Product.Specification = ToModelValue(reader, "Specification").ToString();               projectItem._Product.Unit = ToModelValue(reader, "Unit").ToString();               projectItem.Count = (int)ToModelValue(reader, "Count");               projectItem.TotalMoney = (decimal)ToModelValue(reader, "TotalMoney");               projectItem.UnitPrice = (decimal)ToModelValue(reader, "UnitPrice");                return projectItem;           }

protected object ToModelValue(SqlDataReader reader,string columnName)          {              if(reader.IsDBNull(reader.GetOrdinal(columnName)))              {                  return null;              }              else             {                  return reader[columnName];              }          }

使用GetProjectByCondition方法返回一個封裝成對象的 IEnumerable集合

public IEnumerable<Model.Project> GetProjectByCondition(string projectName, string customerName, string contract, string tel)          {              StringBuilder sqlWhere = new StringBuilder("select * from Project where 1=1");              List<SqlParameter> listParameters = new List<SqlParameter>();              if (!string.IsNullOrWhiteSpace(projectName))              {                  sqlWhere.AppendLine(" and projectName like @projectName");                  listParameters.Add(new SqlParameter("projectName", "%" + projectName + "%"));              }              if (!string.IsNullOrWhiteSpace(contract))              {                  sqlWhere.AppendLine(" and Contact like @Contact");                  listParameters.Add(new SqlParameter("Contact", "%" + contract + "%"));              }              if (!string.IsNullOrWhiteSpace(customerName))              {                  sqlWhere.AppendLine(" and customer like @customer");                  listParameters.Add(new SqlParameter("customer", "%" + customerName + "%"));              }              if (!string.IsNullOrWhiteSpace(tel))              {                  sqlWhere.AppendLine(" and tel like @tel");                  listParameters.Add(new SqlParameter("tel", "%" + tel + "%"));              }              using (SqlDataReader reader = SqlHelper.ExecuteDataReader(sqlWhere.ToString(), listParameters.ToArray()))              {                  return ToModels(reader);              }           }

UpdatePassChecked方法接受一個對象，通過對象的屬性來獲取數據

public int UpdatePassChecked(ProjectItem projectItem)           {               string sql =                   "UPDATE Project " +                   "SET " +               " ProjectName = @ProjectName"                  + ", Customer = @Customer"                  + ", Contact = @Contact"                  + ", Tel = @Tel"                  + ", DeliveryPlace = @DeliveryPlace"                  + ", DeliveryTime = @DeliveryTime"                  + ", TransportCosts = @TransportCosts"                  + ", PaymentTerm = @PaymentTerm"                  + ", Bak = @Bak"               + " WHERE ID = @ID";                 SqlParameter[] para = new SqlParameter[]              {                  new SqlParameter("@ID", projectItem._Project.ID)                      ,new SqlParameter("@ProjectName", ToDBValue(projectItem._Project.ProjectName))                      ,new SqlParameter("@Customer", ToDBValue(projectItem._Project.Customer))                      ,new SqlParameter("@Contact", ToDBValue(projectItem._Project.Contact))                      ,new SqlParameter("@Tel", ToDBValue(projectItem._Project.Tel))                      ,new SqlParameter("@DeliveryPlace", ToDBValue(projectItem._Project.DeliveryPlace))                      ,new SqlParameter("@DeliveryTime", ToDBValue(projectItem._Project.DeliveryTime))                      ,new SqlParameter("@TransportCosts", ToDBValue(projectItem._Project.TransportCosts))                      ,new SqlParameter("@PaymentTerm", ToDBValue(projectItem._Project.PaymentTerm))                      ,new SqlParameter("@Bak", ToDBValue(projectItem._Project.Bak))              };                return SqlHelper.ExecuteNonQuery(sql, para);            }

Add方法傳入一個已經把數據封裝好的對象，然后返回一個新的對象（包含新創建生成的ID）

public Product Add(Product product)          {                  string sql ="INSERT INTO Product (ProductName, Specification, Manufacturer, Parameters, Price, Unit)  output inserted.ID VALUES (@ProductName, @Specification, @Manufacturer, @Parameters, @Price, @Unit)";                  SqlParameter[] para = new SqlParameter[]                      {                          new SqlParameter("@ProductName", ToDBValue(product.ProductName)),                          new SqlParameter("@Specification", ToDBValue(product.Specification)),                          new SqlParameter("@Manufacturer", ToDBValue(product.Manufacturer)),                          new SqlParameter("@Parameters", ToDBValue(product.Parameters)),                          new SqlParameter("@Price", ToDBValue(product.Price)),                          new SqlParameter("@Unit", ToDBValue(product.Unit)),                      };                                        int newId = (int)SqlHelper.ExecuteScalar(sql, para);                  return GetByID(newId);          }

3.業務邏輯層：業務邏輯層是項目的核心，業務邏輯上的代碼通常在這兒實現（一言難盡）。

簡單數據驗證：

public bool UpdateThroughChecked(ProjectItem projectItem)          {              if (string.IsNullOrEmpty(projectItem._Project.ProjectName))              {                  throw new Exception("項目名稱不能為空");              }              //顧客姓名可以為空，但聯系人不能為空，所以數據庫里就應該設計好              if (string.IsNullOrEmpty(projectItem._Project.Contact))              {                  throw new Exception("聯系人姓名不能為空");              }              if (string.IsNullOrEmpty(projectItem._Project.Tel))              {                  throw new Exception("聯系電話不能為空");              }              if (string.IsNullOrEmpty(projectItem._Project.DeliveryPlace))              {                  throw new Exception("交貨地點不能為空");              }              if (string.IsNullOrEmpty(projectItem._Project.DeliveryTime))              {                  throw new Exception("交貨時間不能為空");              }              if (projectItem._Project.TransportCosts<00)              {                  throw new Exception("運輸費用不能為負數");              }              return new DAL.ProjectItemService().UpdatePassChecked(projectItem) > 0;           }

計算總金額：

public decimal GetProductTotalMoney(int projectID)          {              var list = new DAL.ProjectItemService().GetProductTotalMoney(projectID);              decimal  totalMoney = 0.00M;              foreach (var model in list)              {                  totalMoney+=model.TotalMoney.Value;              }              return totalMoney;          }

根據查詢條件獲取數據集合：

/// <summary>          /// 根據查詢條件獲取數據集合          /// </summary>          /// <param name="condition"></param>          /// <returns></returns>          public IEnumerable<Model.Product> GetProductsByCondition(string condition)          {             return new DAL.ProductService().GetProductsByCondition(condition);                   }

根據ProjectItemID獲取一條記錄（封裝成對象）

public Model.ProjectItem GetOneProjectItemByID(int ProjectItemID)          {              return new DAL.ProjectItemService().GetOneProjectItemByID(ProjectItemID);          }

增加一條記錄：

/// <summary>          /// 新增一條記錄 根據條件          /// </summary>          /// <param name="modelProject"></param>          /// <returns></returns>          public Model.Project AddPassCheckd(Model.Project modelProject)          {               if (string.IsNullOrEmpty(modelProject.ProjectName))              {                  throw new Exception("項目名稱不能為空");              }              if (string.IsNullOrEmpty(modelProject.Customer))              {                  throw new Exception("顧客名稱不能為空");              }              if (string.IsNullOrEmpty(modelProject.Tel))              {                  throw new Exception("聯系電話不能為空");              }              if (modelProject.TransportCosts <= 0)              {                  throw new Exception("運輸費用不能為負數:(");              }              return new DAL.ProjectService().Add(modelProject);                       }

刪除一個項目：

/// <summary>          /// 刪除一個項目          /// </summary>          /// <param name="projectID"></param>          /// <returns></returns>          public bool DeleteProject(int projectID)          {               bool isSucceed=  new BLL.ProjectItemManager().DeleteProjectItemsByProjectID(projectID);               isSucceed = new DAL.ProjectService().DeleteByID(projectID) > 0 && isSucceed;               return isSucceed;          }

4.表現層（UI）

簡單的窗體里嵌套窗體：

public void LoadProjectListForm()          {              projectListForm = null;              if (projectListForm==null)              {                  projectListForm = new ProjectListForm();              }              //去掉邊框              projectListForm.FormBorderStyle = FormBorderStyle.None;              projectListForm.TopLevel = false;//窗體是否是頂級窗體              projectListForm.Dock = DockStyle.Fill;//填充              projectListForm.Show();//不寫看不到              panelContainer.Controls.Clear();//清空              panelContainer.Controls.Add(projectListForm);          }

綁定數據：

void LoadData()          {              var list = new BLL.ProjectItemManager().GetAllProducts(projectID);              //dataGridViewProjectItems.DataSource = list;//當控件被綁定時無法向其添加Row              dataGridViewProjectItems.Rows.Clear();              foreach (var model in list)              {                  int i = dataGridViewProjectItems.Rows.Add();                  dataGridViewProjectItems.Rows[i].Cells["idColumn"].Value = model.ID;                  dataGridViewProjectItems.Rows[i].Cells["specificationColumn"].Value = model._Product.Specification;                  dataGridViewProjectItems.Rows[i].Cells["productNameColumn"].Value = model._Product.ProductName;                  dataGridViewProjectItems.Rows[i].Cells["manufacturerColumn"].Value = model._Product.Manufacturer;                  dataGridViewProjectItems.Rows[i].Cells["parametersColumn"].Value = model._Product.Parameters;                  dataGridViewProjectItems.Rows[i].Cells["productIDColumn"].Value = model._Product.ID;                  dataGridViewProjectItems.Rows[i].Cells["totalMoneyColumn"].Value = model.TotalMoney;                  dataGridViewProjectItems.Rows[i].Cells["countColumn"].Value = model.Count;                  dataGridViewProjectItems.Rows[i].Cells["unitPriceColumn"].Value = model.UnitPrice;                  dataGridViewProjectItems.Rows[i].Cells["projectIDColumn"].Value = model._Project.ID;              }

以上就是“如何完成一個小型工程報價數據庫系統”這篇文章的所有內容，感謝各位的閱讀！相信大家閱讀完這篇文章都有很大的收獲，小編每天都會為大家更新不同的知識，如果還想學習更多的知識，請關注億速云行業資訊頻道。