C#数据库操作的三种经典用法

2009年3月28日星期六

C#数据库操作的三种经典用法

由于最近和数据库打交道,需要用C#和SQL Server 2005进行操作,就把近段时间内的最常用的操作做个总结。本人也是第一次用C#操作数据库,所以这三种典型用法对初学者还是挺有帮助的。
  以下是我在visual studio 2005上写的一个类(连的是SQL Server 2005),已经过测试通过。里面有3个方法比较典型,源码如下:
  using System;
  using System.Collections.Generic;
  using System.Text;
  using System.Data;
  using System.Data.SqlClient;
  namespace DatabaseOperate
  {
  class SqlOperateInfo
  {
  //Suppose your ServerName is "aa",DatabaseName is "bb",UserName is "cc", Password is "dd"
  private string sqlConnectionCommand = "Data Source=aa;Initial Catalog=bb;User ID=cc;Pwd=dd";
  //This table contains two columns:KeywordID int not null,KeywordName varchar(100) not null
  private string dataTableName = "Basic_Keyword_Test";
  private string storedProcedureName = "Sp_InertToBasic_Keyword_Test";
  private string sqlSelectCommand = "Select KeywordID, KeywordName From Basic_Keyword_Test";
  //sqlUpdateCommand could contain "insert" , "delete" , "update" operate
  private string sqlUpdateCommand = "Delete From Basic_Keyword_Test Where KeywordID = 1";
  public void UseSqlReader()
  {
  SqlConnection sqlConnection = new SqlConnection(sqlConnectionCommand);
  SqlCommand sqlCommand = new SqlCommand();
  sqlCommand.CommandType = System.Data.CommandType.Text;
  sqlCommand.Connection = sqlConnection;
  sqlCommand.CommandText = sqlSelectCommand;
  sqlConnection.Open();
  SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();
  while(sqlDataReader.Read())
  {
  //Get KeywordID and KeywordName , You can do anything you like. Here I just output them.
  int keywordid = (int)sqlDataReader[0];
  //the same as: int keywordid = (int)sqlDataReader["KeywordID"]
  string keywordName = (string)sqlDataReader[1];
  //the same as: string keywordName = (int)sqlDataReader["KeywordName"]
  Console.WriteLine("KeywordID = " + keywordid + " , KeywordName = " + keywordName);
  }
  sqlDataReader.Close();
  sqlCommand.Dispose();
  sqlConnection.Close();
  }
  public void UseSqlStoredProcedure()
  {
  SqlConnection sqlConnection = new SqlConnection(sqlConnectionCommand);
  SqlCommand sqlCommand = new SqlCommand();
  sqlCommand.CommandType = CommandType.StoredProcedure;
  sqlCommand.Connection = sqlConnection;
  sqlCommand.CommandText = storedProcedureName;
  sqlConnection.Open();
  sqlCommand.ExecuteNonQuery();
  //you can use reader here,too.as long as you modify the sp and let it like select * from ....
  sqlCommand.Dispose();
  sqlConnection.Close();
  }
  public void UseSqlDataSet()
  {
  SqlConnection sqlConnection = new SqlConnection(sqlConnectionCommand);
  SqlCommand sqlCommand = new SqlCommand();
  sqlCommand.CommandType = System.Data.CommandType.Text;
  sqlCommand.Connection = sqlConnection;
  sqlCommand.CommandText = sqlSelectCommand;
  sqlConnection.Open();
  SqlDataAdapter sqlDataAdapter = new SqlDataAdapter();
  sqlDataAdapter.SelectCommand = sqlCommand;
  DataSet dataSet = new DataSet();
  //sqlCommandBuilder is for update the dataset to database
  SqlCommandBuilder sqlCommandBuilder = new SqlCommandBuilder(sqlDataAdapter);
  sqlDataAdapter.Fill(dataSet, dataTableName);
  //Do something to dataset then you can update it to  Database.Here I just add a row
  DataRow row = dataSet.Tables[0].NewRow();
  row[0] = 10000;
  row[1] = "new row";
  dataSet.Tables[0].Rows.Add(row);
  sqlDataAdapter.Update(dataSet, dataTableName);
  sqlCommand.Dispose();
  sqlDataAdapter.Dispose();
  sqlConnection.Close();
  }
  }
  }
  以上的程序概括了最典型的用法,也是最基本的用法.

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