C#数据访问层的相关知识有哪些

这篇文章给大家分享的是有关C#数据访问层的相关知识有哪些的内容。小编觉得挺实用的，因此分享给大家做个参考，一起跟随小编过来看看吧。

C#数据访问层1.查询数据库中的数据，返回一个datatable

C#数据访问层2.执行一条SQL语句已重载

using System;  using System.Data;  using NUnit.Framework;  using CodeFilemanger.Project;  using System.Data.SqlClient;  using System.Configuration;  namespace OperatorDB  {   ///   /// Class1 的摘要说明。  ///   [NUnit.Framework.TestFixture]  public class OperatorDB   {   private static string strCon = ConfigurationSettings.AppSettings["ConnectionString"] ;   private int ModuleId = 1;  public static string ConnectionString   {   get   {   return strCon;   }   set   {   strCon = value;   }   }    #region "初始化"   [NUnit.Framework.TestFixtureSetUp]  public void Register_Module()  {   string ModuleName = "OperatorDB";  string ModuleAuthor = "MYM";  string ModuleDescribe = "数据访问模块";  string CreateDatetime = "2003-5-30";  ModuleId = Project.InsertModule( ModuleName, ModuleAuthor, ModuleDescribe, CreateDatetime) ;   }  [Test]  public void Register_Method_SelectData()  {  string MethodName = "SelectData";  string MethodAuthor = "MYM";  string MethodCreateDateTime = "2005-3-30";  string MethodParaMeters ="ParaMeters(string SqlCommandText, System.Data.DataTable Dt, bool RowsClearr)";  string MethodReturn = "bool";  string MethodCall = "" ;  string MethodDescribe = "查询数据库中的数据，返回一个datatable";  Project.InsertMethod(MethodName,MethodAuthor,MethodCreateDateTime,MethodParaMeters,MethodReturn,MethodCall,MethodDescribe,ModuleId);   }  [Test]  public void Register_Method_ExecuteSql()  {  string MethodName = "ExecuteSql";  string MethodAuthor = "MYM";  string MethodCreateDateTime = "2005-3-30";  string MethodParaMeters ="ParaMeters(string SqlCommandText)";  string MethodReturn = "int";  string MethodCall = "" ;  string MethodDescribe = "执行一条SQL语句";  Project.InsertMethod(MethodName,MethodAuthor,MethodCreateDateTime,MethodParaMeters,MethodReturn,MethodCall,MethodDescribe,ModuleId);   }  [Test]  public void Register_Method_SerialNumber()  {  string MethodName = "SerialNumber";  string MethodAuthor = "MYM";  string MethodCreateDateTime = "2005-3-30";  string MethodParaMeters ="ParaMeters(int index, System.Data.DataTable dt)";  string MethodReturn = "void";  string MethodCall = "" ;  string MethodDescribe = "给表的指定列添加序号";  Project.InsertMethod(MethodName,MethodAuthor,MethodCreateDateTime,MethodParaMeters,MethodReturn,MethodCall,MethodDescribe,ModuleId);   }   #endregion   public static bool SelectData(string SqlCommandText, System.Data.DataTable Dt, bool RowsClearr)   {   strCon = ConfigurationSettings.AppSettings["ConnectionString"];   bool ret = true;   if (SqlCommandText != "")   {   if (RowsClearr)   {   if (Dt.Rows.Count > 0)  {  Dt.Rows.Clear();   }   }   SqlConnection cn = new SqlConnection(strCon);   SqlDataAdapter da = new SqlDataAdapter(SqlCommandText, cn);   try   {   cn.Open();   da.Fill(Dt);   }   catch (System.Exception ex)   {   ExceptionHand exc = new ExceptionHand(ex);   exc.DisplayErrorMessager("OperatorDB","SelectData",SqlCommandText);   ret = false;   }   if (cn.State == ConnectionState.Open)   {   cn.Close();   }   da.Dispose();   }   else   {   ret = false;   }   return ret;   }   public static int ExecuteSql(string SqlCommandText)   {   int ID = 0;   strCon = ConfigurationSettings.AppSettings["ConnectionString"];   if (SqlCommandText != "")   {   SqlConnection cn = new SqlConnection(strCon);   SqlCommand cm = new SqlCommand(SqlCommandText, cn);   try   {   cn.Open();  ID = Convert.ToInt32(cm.ExecuteScalar());  }   catch (System.Exception ex)   {   cn.Close();  ExceptionHand exc = new ExceptionHand(ex);   exc.DisplayErrorMessager("OperatorDB","ExecuteSql",SqlCommandText);   ID = -1;   }    if (cn.State == ConnectionState.Open)   {   cn.Close();   }   cm.Dispose();   }   return ID;   }   public static int ExecuteSql(SqlCommand Cm)   {   int ID = 0;   strCon = ConfigurationSettings.AppSettings["ConnectionString"];   SqlConnection cn = new SqlConnection(strCon);   try   {   cn.Open();   Cm.Connection = cn;  ID = Convert.ToInt32(Cm.ExecuteScalar());   }   catch (System.Exception ex)   {   cn.Close();  ExceptionHand exc = new ExceptionHand(ex);   exc.DisplayErrorMessager("OperatorDB","ExecuteSql",Cm.CommandText);   ID = -1;   }    if (cn.State == ConnectionState.Open)   {   cn.Close();   }   Cm.Dispose();    return ID;   }   public static void SerialNumber(int index, System.Data.DataTable dt)   {   for (int i = 0; i <= dt.Rows.Count - 1; i++)   {   dt.Rows[i][index] = i + 1;   }   }   public static void SetSqlCommandValues(SqlCommand Com,DataTable Dt,int Index,int StartIndex)  {  int i;  for (i=StartIndex;i{  Com.Parameters.Add("@" + Dt.Columns[i].ColumnName,Dt.Rows[Index][i]);  }  }   }  }

感谢各位的阅读！关于"C#数据访问层的相关知识有哪些"这篇文章就分享到这里了，希望以上内容可以对大家有一定的帮助，让大家可以学到更多知识，如果觉得文章不错，可以把它分享出去让更多的人看到吧！