SqlDataReader 与 DataSet读取sql中的数据

using System.Data;

using System.Data.SqlClient;

static void Main(string[] args)

{

//---------------------------------------用SqlDataReader 访问数据 begin------------------------------------------------

/*

* 五个步骤

* 1、连接数据源

* 2、打开连接

* 3、创建一个SQL查询命令

* 4、使用DataReader读取并显示数据

* 5、关闭DataReader和连接

*/

//Integrated Security=true这句指定sql和windows的标准内置安全功能。还可以用（User=sa;PWD=ma）代替它

SqlConnection thisConnection = new SqlConnection(

@"Data Source=.\SQLEXPRESS;"+

@"AttachDbFilename='C:\SQL Server 2000 Sample Databases\NORTHWND.MDF';"

+

@"Integrated Security=true;Connect Timeout=30;User Instance=true");//1、

thisConnection.Open();//2、

SqlCommand thisCommand = thisConnection.CreateCommand();//3、

thisCommand.CommandText =

"select CustomerID,CompanyName from Customers";

SqlDataReader thisReader = thisCommand.ExecuteReader();//4、

while (thisReader.Read())

{

Console.WriteLine("\t{0}\t{1}",

thisReader["CustomerID"], thisReader["CompanyName"]);

}

thisReader.Close();

thisConnection.Close();

Console.WriteLine("program finished,press Enter/Return to continue:");

Console.ReadLine();

//---------------------------------------用SqlDataReader 访问数据 end------------------------------------------------

//---------------------------------------用DataSet 访问数据 begin------------------------------------------------

SqlConnection thisConnection = new SqlConnection(

@"Data Source=.\SQLEXPRESS;" +

@"AttachDbFilename='C:\SQL Server 2000 Sample Databases\NORTHWND.MDF';"

+

@"Integrated Security=true;Connect Timeout=30;User Instance=true");

SqlDataAdapter thisAdapter = new SqlDataAdapter(

"Select CustomerID,ContactName from Customers", thisConnection);

DataSet thisDataSet = new DataSet();

//填充DataSet.第二个参数Customers并不是指Norhwind数据库中的Customers表，它是DataSet中要创建和填充数据的DataTable对象的名称

thisAdapter.Fill(thisDataSet, "Customers");

foreach (DataRow theRow in thisDataSet.Tables["Customers"].Rows)

{

Console.WriteLine(theRow["CustomerID"] + "\t" + theRow["ContactName"]);

}

thisConnection.Close();

Console.WriteLine("program finisher.");

Console.WriteLine();

//---------------------------------------用DataSet 访问数据 begin------------------------------------------------

}

}