<原文地址:http://www.cnblogs.com/xiongeee/archive/2007/03/23/684989.html>
//***********************************************************
//*名稱:一個程序詳細研究DataReader,同時顯示Command用法
//*功能:演示DataReader的各項操作。
//*說明:如果需要文字說明請查看我的BLOG裏面關於ado.net的文章
//*作者:雪冬寒
//*BOLG:[url]http://blog.csdn.net/bineon[/url]
//***********************************************************
using System;
using System.Data;
using System.Data.SqlClient;
using System.Data.OleDb;
class SqlReader
{
const string connStr = "data source=bineon;user id=sa;password=87345587;initial catalog=contract";
SqlConnection conn;
public SqlReader()
{
conn = new SqlConnection(connStr);
}
//**************************************
//*演示DataReader的兩種取值方法
//**************************************
public void basicReader()
{
string sql="select * from friend";
SqlCommand cmd;
cmd = conn.CreateCommand();
cmd.CommandText = sql;
conn.Open();
SqlDataReader reader = cmd.ExecuteReader();
while(reader.Read())
{
Console.WriteLine("No:{0}/tName:{1}/tPhoneNum:{2},/tAddress:{3}",reader.GetInt32(0).ToString(),reader.GetString(1),reader[2].ToString(),reader["Faddress"].ToString());
}
showSplit();
reader.Close();
conn.Close();
}
//**************************************
//*演示帶參數查詢的操作,使用SqlCilent
//**************************************
public void hasParamReader()
{
SqlCommand cmd;
cmd = conn.CreateCommand();
string sql = "select Fname,Fphone,Faddress from friend where Fid > @Fid";
cmd.CommandText = sql;
SqlParameter param = new SqlParameter("@Fid",SqlDbType.Int,4);
param.Value = 15;
cmd.Parameters.Add(param);
conn.Open();
//當關閉reader的時候同時關閉數據庫連接
SqlDataReader reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
while(reader.Read())
{
Console.WriteLine("Name:{0}/tPhoneNum:{1}/tAddress:{2}",reader.GetString(0),reader.GetString(1),reader.GetString(2));
}
showSplit();
//無需關閉conn,系統會自動調用這個方法來關閉conn的。
reader.Close();
}
//**************************************
//*演示帶參數查詢的操作,使用OleDb
//**************************************
public void hasOledbParamReader()
{
SqlCommand cmd;
cmd = conn.CreateCommand();
string sql = "select Fname,Fphone,Faddress from friend where Fid > ?";
string oledbConnStr = "Provider=sqloledb;" + connStr;
OleDbConnection oleConn = new OleDbConnection(oledbConnStr);
OleDbCommand oleCmd = new OleDbCommand(sql,oleConn);
oleCmd.Parameters.Add("nothing",15);
oleConn.Open();
OleDbDataReader oleReader = oleCmd.ExecuteReader();
while(oleReader.Read())
{
Console.WriteLine("Name:{0}/tPhoneNum:{1}/tAddress:{2}",oleReader.GetString(0),oleReader.GetString(1),oleReader.GetString(2));
}
showSplit();
oleReader.Close();
oleConn.Close();
}
//**************************************
//*演示存儲過程的輸出參數
//**************************************
public void outParamShow()
{
SqlCommand cmd;
cmd = conn.CreateCommand();
cmd.CommandText = "GetInfo";
cmd.CommandType = CommandType.StoredProcedure;
SqlParameter param = cmd.Parameters.Add("@Fid",16);
param = cmd.Parameters.Add("@Fname",SqlDbType.VarChar,8);
param.Direction = ParameterDirection.Output;
param = cmd.Parameters.Add("@Fphone",SqlDbType.VarChar,8);
param.Direction = ParameterDirection.Output;
conn.Open();
cmd.ExecuteNonQuery();
string Fname = cmd.Parameters["@Fname"].Value.ToString();
string Fphone = cmd.Parameters["@Fphone"].Value.ToString();
Console.WriteLine(Fname + " " + Fphone);
conn.Close();
showSplit();
}
//**************************************
//*演示讀取多個無關記錄集
//**************************************
public void multiResult()
{
SqlCommand cmd;
cmd = conn.CreateCommand();
string sqla = "select Fname from friend";
string sqlb = "select Fphone from friend";
cmd.CommandText = sqla + ";" + sqlb;
conn.Open();
SqlDataReader reader= cmd.ExecuteReader();
int i = 1;
do
{
Console.WriteLine("第" + i.ToString() + "個記錄集內容如下:/n");
while(reader.Read())
{
Console.WriteLine(reader[0].ToString() + "/t");
}
i++;
}while(reader.NextResult()); //NextResult()移動到下一個記錄集
reader.Close();
conn.Close();
showSplit();
}
//**************************************
//*使用DataReader獲得數據庫模式信息
//**************************************
public void getSchema()
{
SqlCommand cmd;
cmd = conn.CreateCommand();
string sql = "select Fid,Fname,Fphone from friend";
cmd.CommandText = sql;
conn.Open();
SqlDataReader reader = cmd.ExecuteReader();
DataTable SchemaTable = reader.GetSchemaTable();
DataRowCollection SchemaColumns = SchemaTable.Rows;
DataColumnCollection SchemaProps = SchemaTable.Columns;
foreach(DataRow SchemaColumn in SchemaColumns)
{
foreach(DataColumn SchemaColumnProp in SchemaProps)
{
Console.WriteLine(SchemaColumnProp.ColumnName + "=" + SchemaColumn[SchemaColumnProp.ColumnName].ToString());
}
}
reader.Close();
conn.Close();
showSplit();
}
//**************************************
//*從數據庫讀取二進制數據的代碼段
//*該代碼段只是讀取二進制的片斷,不是
//*整個程序,所以不能執行,你可以把它
//*集成到你的WinForm項目裏面。
//**************************************
public void getBinary()
{
/*
System.IO.MemoryStream stream = new System.IO.MemoryStream();
System.IO.BinaryWriter writer = new System.IO.BinaryWriter(stream);
int BufferSize = 1024;
byte[] Buffer = new Byte[BufferSize];
long Offset = 0;
long BytesRead = 0;
do
{
BytesRead = reader.GetBytes(2,Offset,Buffer,0,BufferSize);
writer.Writer(Buffer,0,(int)BytesRead);
writer.Flush();
Offset += BytesRead;
}
while(BytesRead == BufferSize);
*/
}
//添加輸出分隔
private void showSplit()
{
Console.WriteLine("/n********************************************************************/n");
}
public static void Main(string [] args)
{
SqlReader sqlreader = new SqlReader();
sqlreader.basicReader();
sqlreader.hasParamReader();
sqlreader.hasOledbParamReader();
sqlreader.outParamShow();
sqlreader.multiResult();
sqlreader.getSchema();
}
}