.net用工厂模式开发多数据库连接类

.net用工厂模式开发多数据库连接类 http://www.diybl.com/　

http://www.cublog.cn/u1/38200/showart_1982199.html

用工厂模式开发多数据库连接类，是工厂模式最好的应用方式，也是很多初级使用设计模式的程序员都会涉及到的，下面是具体代码：
A、创建一个类库，里面有如下这些类
一、设计一个抽象类

   
     

    
      using
    
       System;

    
      using
    
       System.Collections.Generic;

    
      using
    
       System.Text;

    
      using
    
       System.Data;

    
      using
    
       System.Configuration;


    
      //
    
      工厂模式连接数据库
    
      

    
      namespace
    
       DBAccess
...{
 
    
      //
    
      数据连接的工厂模式抽象类
    
      

    
       
    
      public
    
       
    
      abstract
    
       
    
      class
    
       DBabstract
 ...{
 
    
      //
    
      构造函数
    
      

    
       
    
      public
    
       DBabstract()
 ...{ 
 }

 
    
      //
    
      打开一个连接
    
      

    
       
    
      public
    
       
    
      abstract
    
       
    
      void
    
       Open();

 
    
      //
    
      关闭一个连接
    
      

    
       
    
      public
    
       
    
      abstract
    
       
    
      void
    
       Close();

 
    
      //
    
      数据读取的公共数
    
      

    
       
    
      public
    
       
    
      abstract
    
       
    
      void
    
       PublicClass(
    
      string
    
       procname, 
    
      object
    
      [] parmas);

 
    
      //
    
      执行无返回DataSet的函数
    
      

    
       
    
      public
    
       
    
      abstract
    
       
    
      string
    
       Execsql(
    
      string
    
       procname, 
    
      object
    
      [] parmas);

 
    
      //
    
      执行有返回DataSet的函数
    
      

    
       
    
      public
    
       
    
      abstract
    
       DataSet ExecSqlReturnDataSet(
    
      string
    
       tablename, 
    
      string
    
       procname, 
    
      object
    
      [] parmas);

 }
}
二、定义一个Oracle连接类



    
      using
    
       System;

    
      using
    
       System.Collections.Generic;

    
      using
    
       System.Text;

    
      using
    
       System.Data;

    
      using
    
       System.Data.OracleClient;

    
      using
    
       System.Configuration;


    
      //
    
      工厂模式连接数据库中的ORACLE数据库连接
    
      

    
      namespace
    
       DBAccess
...{
 
    
      //
    
      数据连接的工厂模式ORACLE连接类
    
      

    
       
    
      internal
    
       
    
      class
    
       DBOracle : DBabstract
 ...{
 
    
      private
    
       OracleConnection conn 
    
      =
    
       
    
      null
    
      ; 
    
      //
    
      数据连接
    
      

    
       
    
      private
    
       OracleCommand cmd 
    
      =
    
       
    
      null
    
      ; 
    
      //
    
      连接命令

 
    
      //
    
      构造函数
    
      

    
       
    
      public
    
       DBOracle(
    
      string
    
       constring)
 ...{
 
    
      this
    
      .conn 
    
      =
    
       
    
      new
    
       OracleConnection(constring);
 }

 
    
      //
    
      打开一个连接
    
      

    
       
    
      public
    
       
    
      override
    
       
    
      void
    
       Open()
 ...{
 
    
      if
    
       (
    
      this
    
      .conn 
    
      !=
    
       
    
      null
    
       
    
      &&
    
       
    
      this
    
      .conn.State 
    
      ==
    
       ConnectionState.Closed)
 ...{
 
    
      this
    
      .conn.Open();
 }
 }

 
    
      //
    
      关闭一个连接
    
      

    
       
    
      public
    
       
    
      override
    
       
    
      void
    
       Close()
 ...{
 
    
      if
    
       (
    
      this
    
      .conn 
    
      !=
    
       
    
      null
    
       
    
      &&
    
       
    
      this
    
      .conn.State 
    
      ==
    
       ConnectionState.Open)
 ...{
 
    
      this
    
      .conn.Close();
 }
 }

 
    
      //
    
      数据读取的公共数
    
      

    
       
    
      public
    
       
    
      override
    
       
    
      void
    
       PublicClass(
    
      string
    
       procname, 
    
      object
    
      [] parmas)
 ...{
 OracleParameter[] Oracleparmas 
    
      =
    
       (OracleParameter[])parmas;
 
    
      this
    
      .cmd 
    
      =
    
       
    
      new
    
       OracleCommand();
 
    
      this
    
      .cmd.Connection 
    
      =
    
       
    
      this
    
      .conn;
 
    
      this
    
      .cmd.CommandType 
    
      =
    
       CommandType.StoredProcedure;
 
    
      this
    
      .cmd.CommandText 
    
      =
    
       procname;
 
    
      if
    
       (
    
      this
    
      .cmd.Parameters.Count 
    
      >
    
       
    
      0
    
      )
 ...{
 
    
      this
    
      .cmd.Parameters.Clear();
 }
 
    
      if
    
       (Oracleparmas 
    
      !=
    
       
    
      null
    
       
    
      &&
    
       Oracleparmas.Length 
    
      >
    
       
    
      0
    
      )
 ...{
 
    
      foreach
    
       (OracleParameter p 
    
      in
    
       Oracleparmas)
 ...{
 
    
      this
    
      .cmd.Parameters.Add(p);
 }
 }
 }

 
    
      //
    
      执行无返回DataSet的函数
 
    
      //
    
      <param name="procname">存储过程名</param>
 
    
      //
    
      <param name="parmas">参数数组</param>
    
      

    
       
    
      public
    
       
    
      override
    
       
    
      string
    
       Execsql(
    
      string
    
       procname, 
    
      object
    
      [] parmas)
 ...{
 
    
      try
    
      
 ...{
 OracleParameter[] Oracleparmas 
    
      =
    
       (OracleParameter[])parmas;
 
    
      this
    
      .Open();
 
    
      this
    
      .PublicClass(procname, Oracleparmas);
 
    
      int
    
       var 
    
      =
    
       
    
      this
    
      .cmd.ExecuteNonQuery();
 
    
      this
    
      .cmd.Parameters.Clear();
 
    
      this
    
      .Close();
 
    
      return
    
       Convert.ToString(var);
 }
 
    
      catch
    
      (Exception ex)
 ...{
 
    
      string
    
       e 
    
      =
    
       ex.Message;
 
    
      this
    
      .Close();
 
    
      throw
    
      ;
 }
 }

 
    
      //
    
      执行有返回DataSet的函数
 
    
      //
    
      <param name="tablename">DataSet表名</param>
 
    
      //
    
      <param name="procname">存储过程名</param>
 
    
      //
    
      <param name="parmas">参数数组</param>
    
      

    
       
    
      public
    
       
    
      override
    
       DataSet ExecSqlReturnDataSet(
    
      string
    
       tablename, 
    
      string
    
       procname, 
    
      object
    
      [] parmas)
 ...{
 
    
      try
    
      
 ...{
 OracleParameter[] Oracleparmas 
    
      =
    
       (OracleParameter[])parmas;
 
    
      this
    
      .PublicClass(procname, Oracleparmas);
 DataSet ds 
    
      =
    
       
    
      new
    
       DataSet();
 
    
      using
    
       (OracleDataAdapter da 
    
      =
    
       
    
      new
    
       OracleDataAdapter())
 ...{
 da.SelectCommand 
    
      =
    
       
    
      this
    
      .cmd;
 da.Fill(ds, tablename);
 }
 
    
      return
    
       ds;

 }
 
    
      catch
    
       (Exception ex)
 ...{
 
    
      string
    
       e 
    
      =
    
       ex.Message;
 
    
      throw
    
      ;
 }
 }
 }
}
三、定义一个SQLSERVER连接类



    
      using
    
       System;

    
      using
    
       System.Collections.Generic;

    
      using
    
       System.Text;

    
      using
    
       System.Data;

    
      using
    
       System.Data.SqlClient;

    
      using
    
       System.Configuration;


    
      //
    
      工厂模式连接数据库中的SQLSERVER数据库连接
    
      

    
      namespace
    
       DBAccess
...{
 
    
      //
    
      数据连接的工厂模式SQLSERVER连接类
    
      

    
       
    
      internal
    
       
    
      class
    
       DBMSSOLServer : DBabstract
 ...{
 
    
      private
    
       SqlConnection conn 
    
      =
    
       
    
      null
    
      ;
 
    
      private
    
       SqlCommand cmd 
    
      =
    
       
    
      null
    
      ;

 
    
      //
    
      构造函数
    
      

    
       
    
      public
    
       DBMSSOLServer(
    
      string
    
       constring)
 ...{
 
    
      this
    
      .conn 
    
      =
    
       
    
      new
    
       SqlConnection(constring);
 }

 
    
      //
    
      打开一个连接
    
      

    
       
    
      public
    
       
    
      override
    
       
    
      void
    
       Open()
 ...{
 
    
      if
    
       (
    
      this
    
      .conn 
    
      !=
    
       
    
      null
    
       
    
      &&
    
       
    
      this
    
      .conn.State 
    
      ==
    
       ConnectionState.Closed)
 ...{
 
    
      this
    
      .conn.Open();
 }
 }

 
    
      //
    
      关闭一个连接
    
      

    
       
    
      public
    
       
    
      override
    
       
    
      void
    
       Close()
 ...{
 
    
      if
    
       (
    
      this
    
      .conn 
    
      !=
    
       
    
      null
    
       
    
      &&
    
       
    
      this
    
      .conn.State 
    
      ==
    
       ConnectionState.Open)
 ...{
 
    
      this
    
      .conn.Close();
 }
 }

 
    
      //
    
      数据读取的公共数
    
      

    
       
    
      public
    
       
    
      override
    
       
    
      void
    
       PublicClass(
    
      string
    
       procname, 
    
      object
    
      [] parmas)
 ...{
 SqlParameter[] SQLparmas 
    
      =
    
       (SqlParameter[])parmas;
 
    
      this
    
      .cmd 
    
      =
    
       
    
      new
    
       SqlCommand();
 
    
      this
    
      .cmd.Connection 
    
      =
    
       
    
      this
    
      .conn;
 
    
      this
    
      .cmd.CommandType 
    
      =
    
       CommandType.StoredProcedure;
 
    
      this
    
      .cmd.CommandText 
    
      =
    
       procname;
 
    
      if
    
       (
    
      this
    
      .cmd.Parameters.Count 
    
      >
    
       
    
      0
    
      )
 ...{
 
    
      this
    
      .cmd.Parameters.Clear();
 }
 
    
      if
    
      (SQLparmas 
    
      !=
    
       
    
      null
    
       
    
      &&
    
       SQLparmas.Length 
    
      >
    
       
    
      0
    
       )
 ...{
 
    
      foreach
    
       (SqlParameter p 
    
      in
    
       SQLparmas)
 ...{
 
    
      this
    
      .cmd.Parameters.Add(p);
 }
 }
 }

 
    
      //
    
      执行无返回DataSet的函数
    
      

    
       
    
      public
    
       
    
      override
    
       
    
      string
    
       Execsql(
    
      string
    
       procname, 
    
      object
    
      [] parmas)
 ...{
 
    
      try
    
      
 ...{
 SqlParameter[] SQLparmas 
    
      =
    
       (SqlParameter[])parmas;
 
    
      this
    
      .Open();
 
    
      this
    
      .PublicClass(procname, SQLparmas);
 
    
      int
    
       var 
    
      =
    
       
    
      this
    
      .cmd.ExecuteNonQuery();
 
    
      this
    
      .cmd.Parameters.Clear();
 
    
      this
    
      .Close();
 
    
      return
    
       Convert.ToString(var);
 }
 
    
      catch
    
       (Exception ex)
 ...{
 
    
      string
    
       e 
    
      =
    
       ex.Message;
 
    
      this
    
      .Close();
 
    
      throw
    
      ;
 }
 }

 
    
      //
    
      执行有返回DataSet的函数
    
      

    
       
    
      public
    
       
    
      override
    
       DataSet ExecSqlReturnDataSet(
    
      string
    
       tablename, 
    
      string
    
       procname, 
    
      object
    
      [] parmas)
 ...{
 
    
      try
    
      
 ...{
 SqlParameter[] SQLparmas 
    
      =
    
       (SqlParameter[])parmas;
 
    
      this
    
      .PublicClass(procname, SQLparmas);
 DataSet ds 
    
      =
    
       
    
      new
    
       DataSet();
 
    
      using
    
       (SqlDataAdapter da 
    
      =
    
       
    
      new
    
       SqlDataAdapter())
 ...{
 da.SelectCommand 
    
      =
    
       
    
      this
    
      .cmd;
 da.Fill(ds, tablename);
 }
 
    
      return
    
       ds;

 }
 
    
      catch
    
       (Exception ex)
 ...{
 
    
      string
    
       e 
    
      =
    
       ex.Message;
 
    
      throw
    
      ;
 }
 }
 }
}
四、创建工厂



    
      using
    
       System;

    
      using
    
       System.Collections.Generic;

    
      using
    
       System.Text;

    
      using
    
       System.Data;


    
      //
    
      工厂类,数据连接类生成器
    
      

    
      namespace
    
       DBAccess
...{
 
    
      public
    
       
    
      class
    
       FactoryClass
 ...{
 
    
      //
    
      数据库连接工厂生成器
 
    
      //
    
      <param name="constring">数据库连接字符串</param>
    
      

    
       
    
      public
    
       DBabstract GetDB(
    
      string
    
       constring,
    
      string
    
       MyDBType)
 ...{
 
    
      if
    
       (MyDBType 
    
      ==
    
       
    
      "
    
      Oracle
    
      "
    
      )
 ...{
 
    
      return
    
       
    
      new
    
       DBOracle(constring);
 }
 
    
      else
    
       
    
      if
    
       (MyDBType 
    
      ==
    
       
    
      "
    
      MSSQLSERVER
    
      "
    
      )
 ...{
 
    
      return
    
       
    
      new
    
       DBMSSOLServer(constring);
 }
 
    
      else
    
       
    
      if
    
       (MyDBType 
    
      ==
    
       
    
      "
    
      ACCESS
    
      "
    
      )
 ...{
 
    
      return
    
       
    
      new
    
       DBMSAccess(constring);
 }
 
    
      else
    
      
 ...{
 
    
      return
    
       
    
      null
    
      ;
 }
 }
 }
}
B、生成解决方案，产生DLL
C、在另外的工程中引用上面产生的DLL
D、使用DLL连接数据库，输入数据



    
      using
    
       System;

    
      using
    
       System.Collections.Generic;

    
      using
    
       System.ComponentModel;

    
      using
    
       System.Data;

    
      using
    
       System.Drawing;

    
      using
    
       System.Text;

    
      using
    
       System.Windows.Forms;

    
      using
    
       System.Data.OracleClient;


    
      namespace
    
       FeatureInfo
...{
 
    
      public
    
       
    
      partial
    
       
    
      class
    
       frmRead : Form
 ...{
 
    
      public
    
       frmRead()
 ...{
 InitializeComponent();
 }

 
    
      private
    
       DBAccess.FactoryClass fac 
    
      =
    
       
    
      null
    
      ;
 
    
      private
    
       DBAccess.DBabstract dba 
    
      =
    
       
    
      null
    
      ;

 
    
      private
    
       
    
      void
    
       frmRead_Load(
    
      object
    
       sender, EventArgs e)
 ...{
 fac 
    
      =
    
       
    
      new
    
       DBAccess.FactoryClass();

 dba 
    
      =
    
       fac.GetDB(System.Configuration.ConfigurationSettings.AppSettings[
    
      "
    
      Oracle
    
      "
    
      ], 
    
      "
    
      Oracle
    
      "
    
      );
 }

 
    
      private
    
       
    
      void
    
       GetClient(MapXLib.Feature ftr) 
    
      //
    
      因是针对MapX开发，所以有这个参数
    
      

    
       ...{
 MapXLib.Feature fftr 
    
      =
    
       ftr; 
    
      //
    
      定义一个MapX图元对象
    
      

    
       
    
      string
    
       ftrid 
    
      =
    
       fftr.KeyValue; 
    
      //
    
      取值
    
      

    
       map.Layers[
    
      this
    
      .layername].KeyField 
    
      =
    
       
    
      "
    
      EquipID
    
      "
    
      ;
 MapXLib.Feature eftr 
    
      =
    
       ftr;
 
    
      string
    
       eqid 
    
      =
    
       eftr.KeyValue;
 map.Layers[
    
      this
    
      .layername].KeyField 
    
      =
    
       
    
      "
    
      ShortName
    
      "
    
      ;
 MapXLib.Feature sftr 
    
      =
    
       ftr;
 
    
      string
    
       shortname 
    
      =
    
       sftr.KeyValue;
 map.Layers[
    
      this
    
      .layername].KeyField 
    
      =
    
       
    
      "
    
      FtrID
    
      "
    
      ;

 
    
      //
    
      创建OracleParameter数组
    
      

    
       OracleParameter[] parmas 
    
      =
    
       
    
      new
    
       OracleParameter[
    
      3
    
      ] ...{
 
    
      new
    
       OracleParameter(
    
      "
    
      nftr
    
      "
    
      ,OracleType.VarChar,
    
      13
    
      ),
 
    
      new
    
       OracleParameter(
    
      "
    
      neqid
    
      "
    
      ,OracleType.VarChar,
    
      50
    
      ),
 
    
      new
    
       OracleParameter(
    
      "
    
      nshortname
    
      "
    
      ,OracleType.VarChar,
    
      14
    
      )
 };
 
    
      if
    
       (ftrid 
    
      !=
    
       
    
      null
    
      )
 ...{
 parmas[
    
      0
    
      ].Value 
    
      =
    
       ftrid;
 }
 
    
      else
    
      
 ...{
 parmas[
    
      0
    
      ].Value 
    
      =
    
       DBNull.Value;
 }
 
    
      if
    
       (eqid 
    
      !=
    
       
    
      null
    
      )
 ...{
 parmas[
    
      1
    
      ].Value 
    
      =
    
       eqid;
 }
 
    
      else
    
      
 ...{
 parmas[
    
      1
    
      ].Value 
    
      =
    
       DBNull.Value;
 }
 
    
      if
    
       (shortname 
    
      !=
    
       
    
      null
    
      )
 ...{
 parmas[
    
      2
    
      ].Value 
    
      =
    
       shortname;
 }
 
    
      else
    
      
 ...{
 parmas[
    
      2
    
      ].Value 
    
      =
    
       DBNull.Value;
 }

 
    
      string
    
       t 
    
      =
    
       dba.Execsql(
    
      "
    
      pro_insertClient
    
      "
    
      , (
    
      object
    
      [])parmas); 

    
      //
    
      执行输入操作，将OracleParameter数组强制转换成Object数组做为参数传入函数
    
      

    
       }
 }
}
   
     

因为当前的要求只是输入数据，所以只写了一个执行insert存储过程的示例，下次将提供C#连接Oracle数据库执行查询的数据集返回的示例，希望大家多多指教！

原文地址 http://www.diybl.com/course/4_webprogram/asp.net/netjs/2008331/107893.html