为 ASP.NET 网站创建 DAL

Posted 2023-02-24

【中文标题】为 ASP.NET 网站创建 DAL

【英文标题】：Creating DAL for ASP.NET website

【发布时间】：2013-02-23 20:58:08

【问题描述】：

我正在使用 Microsoft Visual Studio DAL，我正在使用传统的方法来获取/更新数据，以通过从网站数据库的 ItemDetails 表中检索数据来显示网站所列项目的评论, 用于创建 ItemDetails.aspx 文件。我添加了DropDownList Control 来显示其类别中的所有项目。 从下拉列表中选择类别时，它会显示该类别中的所有项目，并附有一个超链接"Show Details" 以在网格视图中显示详细信息。 我是新手，我不知道为 asp.net 网站创建DAL。需要简单的指南来为 asp.net 网站创建 DAL。帮助将不胜感激。除了SQLadapter，还有什么其他方法可以创建 DAL。

【问题讨论】：

我个人使用实体框架代码优先（我将表定义为具有强类型引用的类）。它动态生成 Db，然后我使用存储库模式进行查询，例如...User user = UserRepo.Single(x=>x.Username=="Bob"); 抛出 UnitOfWork 模式以保存更改，这是一个非常优雅且相对高效的 ORM。请注意，一个主要缺点是批量更新可能很慢 - 当您一次更新数十万条记录时，更容易退回到 Sql 适配器。

我想将它用于有近 15-17 个页面和 60 个数据库表的网站。

这不是一个真正的问题。我在一个有大约 100 个表格和数百个页面的网站上使用过它。批量更新是一个问题的唯一原因是它们没有批量发送到 SQL - 例如它确实 UPDATE A set B=C WHERE Id = 1、UPDATE A set B=C WHERE Id = 2 等而不是 UPDATE A set B=C WHERE Id IN (1,2) 但除非您对数千个执行相同的更新同时行，这不是问题

【参考方案1】：

例如，这里是我之前用于调用 SP 的 DAL。

它允许您执行存储过程并返回数据集、数据表、成功响应等。

实际上，这取决于您打算如何访问数据，您是编写存储过程还是在代码中进行查询。您还可以选择使用实体框架/LINQ。

using System;
using System.Collections.Generic;
using System.Web;
using System.Data;
using System.Data.Sql;
using System.Data.SqlClient;
using System.Configuration;

public class _DataInteraction


    #region "Stored Procedures"

    public static DataTable stdReturnDataTableQuery(string procedureName, string db)
    
        DataTable myDataTable;

        SqlConnection myConnection = new SqlConnection(ConfigurationManager.ConnectionStrings[db].ConnectionString);
        SqlCommand cmd = new SqlCommand();
        SqlDataAdapter myDataAdapter = new SqlDataAdapter();

        cmd.CommandText = procedureName;
        cmd.CommandType = CommandType.Text;
        cmd.Connection = myConnection;


        //-----------------------------------------------------------------------
        // make our datatable to return
        //-----------------------------------------------------------------------
        myDataTable = new DataTable();

        //-----------------------------------------------------------------------
        // fill the datatable with the stored procedure results
        //-----------------------------------------------------------------------
        try
        
            myConnection.Open();
            myDataAdapter.SelectCommand = cmd;
            myDataAdapter.Fill(myDataTable);
        
        catch (Exception ex)
        
            //flag as error happened
            throw ex;
        
        finally
        
            myConnection.Close();
            if ((myDataAdapter != null))
                myDataAdapter.Dispose();
            if ((cmd != null))
                cmd.Dispose();
        

        return myDataTable;
    


    //   Return a datatable from the database
    public static DataTable stdReturnDataTable(string procedureName, List<SqlParameter> myParameters, string db)
    
        SqlConnection myConnection = default(SqlConnection);
        SqlCommand myCommand = default(SqlCommand);
        SqlDataAdapter myDataAdapter = default(SqlDataAdapter);
        DataTable myDataTable = default(DataTable);
        string connString = null;

        //   -----------------------------------------------------------------------
        //   create instance of connection
        //   -----------------------------------------------------------------------
        connString = ConfigurationManager.ConnectionStrings[db].ConnectionString;
        myConnection = new SqlConnection();
        myConnection.ConnectionString = connString;

        //-----------------------------------------------------------------------
        //   create instance of command and dataadapter
        //-----------------------------------------------------------------------
        myCommand = new SqlCommand(procedureName, myConnection);
        myDataAdapter = new SqlDataAdapter(myCommand);

        //-----------------------------------------------------------------------
        //   say its a stored procedure command
        //-----------------------------------------------------------------------
        myCommand.CommandType = CommandType.StoredProcedure;

        //-----------------------------------------------------------------------
        //   add any parameters?
        //-----------------------------------------------------------------------
        if ((myParameters != null))
        
            foreach (SqlParameter myParm in myParameters)
            
                // add the parameter to the command
                myCommand.Parameters.Add(myParm);
            
        

        //-----------------------------------------------------------------------
        // make our datatable to return
        //-----------------------------------------------------------------------
        myDataTable = new DataTable();

        //-----------------------------------------------------------------------
        // fill the datatable with the stored procedure results
        //-----------------------------------------------------------------------
        try
        
            myConnection.Open();
            myDataAdapter.Fill(myDataTable);
        
        catch (Exception ex)
        
            //flag as error happened
            throw ex;
        
        finally
        
            myConnection.Close();
            if ((myDataAdapter != null))
                myDataAdapter.Dispose();
            if ((myCommand != null))
                myCommand.Dispose();
        

        return myDataTable;
    

    //   Return a dataset from the database
    public static DataSet stdReturnDataset(string procedureName, List<SqlParameter> myParameters, string db)
    
        SqlConnection myConnection = default(SqlConnection);
        SqlCommand myCommand = default(SqlCommand);
        SqlDataAdapter myDataAdapter = default(SqlDataAdapter);
        DataSet ds = new DataSet();
        string connString = null;

        //-----------------------------------------------------------------------
        //   create instance of connection
        //-----------------------------------------------------------------------
        connString = ConfigurationManager.ConnectionStrings[db].ConnectionString;
        myConnection = new SqlConnection();
        myConnection.ConnectionString = connString;

        //-----------------------------------------------------------------------
        //   create instance of command and dataadapter
        //-----------------------------------------------------------------------
        myCommand = new SqlCommand(procedureName, myConnection);
        myDataAdapter = new SqlDataAdapter(myCommand);

        //-----------------------------------------------------------------------
        //   say its a stored procedure command
        //-----------------------------------------------------------------------
        myCommand.CommandType = CommandType.StoredProcedure;

        //-----------------------------------------------------------------------
        //   add any parameters?
        //-----------------------------------------------------------------------
        if ((myParameters != null))
        
            foreach (SqlParameter myParm in myParameters)
            
                // add the parameter to the command
                myCommand.Parameters.Add(myParm);
            
        

        //-----------------------------------------------------------------------
        // fill the datatable with the stored procedure results
        //-----------------------------------------------------------------------
        try
        
            myConnection.Open();
            myDataAdapter.Fill(ds);
        
        catch (Exception ex)
        
            //flag as error happened
            throw ex;
        
        finally
        
            myConnection.Close();
            if ((myDataAdapter != null))
                myDataAdapter.Dispose();
            if ((myCommand != null))
                myCommand.Dispose();
        

        return ds;
    

    //   Return success from a query from the database
    public static bool db_NonQuerySuccessResponse(string strCommandText, List<SqlParameter> myParameters, string db)
    
        SqlConnection SQLConnection = new SqlConnection(ConfigurationManager.ConnectionStrings[db].ConnectionString);
        SqlCommand SQLCommand = new SqlCommand();
        DataSet ds = new DataSet();
        string Value = "";
        bool success = false;

        try
        
            SQLCommand.CommandText = strCommandText;
            SQLCommand.CommandType = CommandType.StoredProcedure;
            SQLCommand.Parameters.Clear();

            if ((myParameters != null))
            
                foreach (SqlParameter myParm in myParameters)
                
                    // add the parameter to the command
                    SQLCommand.Parameters.Add(myParm);
                
            

            SQLCommand.Connection = SQLConnection;
            SQLConnection.Open();
            SQLCommand.ExecuteNonQuery();
            SQLConnection.Close();

            success = true;

        
        catch (Exception ex)
        
            success = false;
            return success;
        

        return success;

    

    //   General non query, no results no success
    public static bool db_NonQuery(string strCommandText, List<SqlParameter> myParameters, string db)
    


        SqlConnection SQLConnection = new SqlConnection(ConfigurationManager.ConnectionStrings[db].ConnectionString);
        SqlCommand SQLCommand = new SqlCommand();
        DataSet ds = new DataSet();

        try
        
            SQLCommand.CommandText = strCommandText;
            SQLCommand.CommandType = CommandType.StoredProcedure;
            SQLCommand.Parameters.Clear();

            if ((myParameters != null))
            
                foreach (SqlParameter myParm in myParameters)
                
                    // add the parameter to the command
                    SQLCommand.Parameters.Add(myParm);
                
            

            SQLCommand.Connection = SQLConnection;
            SQLConnection.Open();
            SQLCommand.ExecuteNonQuery();
            SQLConnection.Close();

        
        catch (Exception ex)
        
            return false;
        

        return true;

    

    ////   Execute scalar on db
    //public static string db_Scalar(string strCommandText, ref List<SqlParameter> myParameters, string db)
    //

    //    SqlConnection SQLConnection = new SqlConnection(ConfigurationManager.ConnectionStrings[db].ConnectionString);
    //    SqlCommand SQLCommand = new SqlCommand();
    //    string Value = "";

    //    SQLCommand.CommandText = strCommandText;
    //    SQLCommand.CommandType = CommandType.StoredProcedure;
    //    SQLCommand.Parameters.Clear();


    //    if ((myParameters != null))
    //    
    //        foreach (SqlParameter myParm in myParameters)
    //        
    //            // add the parameter to the command
    //            SQLCommand.Parameters.Add(myParm);
    //        
    //    

    //    SQLCommand.Connection = SQLConnection;
    //    SQLConnection.Open();
    //    Value = SQLCommand.ExecuteScalar;
    //    SQLConnection.Close();
    //    return Value;
    //

    #endregion

【参考方案2】：

以下是1个样本供参考............

        public List<T> GetRequests(string strNo)
    
        List<T> objlstMapping = null;
        Mapping objMapping = null;
        try
        
            Database objDbInstance = CreateSQLDatabase(DbConnection.MF);

            using (DbCommand objDbCommand = objDbInstance.GetStoredProcCommand(Constants.SP_QUESTS))
            
                DALBase.AddDbParam(objDbInstance, objDbCommand, "@No", DbType.AnsiString, ParameterDirection.Input, strFolioNo);

                objDbCommand.Connection = objDbInstance.CreateConnection();
                objDbCommand.Connection.Open();
                using (DbDataReader dr = objDbCommand.ExecuteReader(CommandBehavior.CloseConnection))
                
                    objMapping = new List<T>();
                    if (dr.HasRows)
                    
                        while (dr.Read())
                        
                            objMapping = new BrokerFolioMapping();
                            objMapping .Brok_Code = SProposedValue(dr, "Code");
                            objMapping .Active = SProposedValue(dr, "Status");
                            objMapping .AccStmt_Active = SProposedValue(dr, "Portfoliostatus");

                            objlstFolioMapping.Add(objMapping );
                        
                    
                
            
        
        catch (Exception ex)
        
                        
        return objlstFolioMapping;