C# DataReader的详细用法

1//DataReader的详细用法  
  2   cmd.CommandText = "GetInfo"; 
  3  cmd.CommandType = CommandType.StoredProcedure; 
  4  SqlParameter param = cmd.Parameters.Add("@Fid",16); 
  5  param = cmd.Parameters.Add("@Fname",SqlDbType.VarChar,8); 
  6  param.Direction = ParameterDirection.Output; 
  7  param = cmd.Parameters.Add("@Fphone",SqlDbType.VarChar,8); 
  8  param.Direction = ParameterDirection.Output; 
  9  conn.Open(); 
 10  cmd.ExecuteNonQuery(); 
 11  string Fname = cmd.Parameters["@Fname"].Value.ToString(); 
 12  string Fphone = cmd.Parameters["@Fphone"].Value.ToString(); 
 13  Console.WriteLine(Fname + "  " + Fphone); 
 14  conn.Close(); 
 15  showSplit(); 
 16 } 
 17  
 18 //************************************** 
 19 //*演示读取多个无关记录集 
 20 //**************************************  
 21 public void multiResult() 
 22 { 
 23  SqlCommand cmd;  
 24  cmd = conn.CreateCommand(); 
 25  string sqla = "select Fname from friend"; 
 26  string sqlb = "select Fphone from friend"; 
 27  cmd.CommandText = sqla + ";" + sqlb; 
 28  conn.Open(); 
 29  SqlDataReader reader= cmd.ExecuteReader(); 
 30  int i = 1; 
 31  do 
 32  { 
 33   Console.WriteLine("第" + i.ToString() + "个记录集内容如下：\n"); 
 34   while(reader.Read()) 
 35   { 
 36    Console.WriteLine(reader[0].ToString() + "\t"); 
 37   } 
 38   i++; 
 39  }while(reader.NextResult()); //NextResult()移动到下一个记录集 
 40  reader.Close(); 
 41  conn.Close(); 
 42  showSplit(); 
 43 } 
 44  
 45 //************************************** 
 46 //*使用DataReader获得数据库模式信息 
 47 //**************************************  
 48 public void getSchema() 
 49 { 
 50  SqlCommand cmd;  
 51  cmd = conn.CreateCommand(); 
 52  string sql = "select Fid,Fname,Fphone from friend"; 
 53     cmd.CommandText = sql; 
 54     conn.Open(); 
 55     SqlDataReader reader = cmd.ExecuteReader(); 
 56     DataTable SchemaTable = reader.GetSchemaTable(); 
 57      
 58     DataRowCollection SchemaColumns = SchemaTable.Rows; 
 59     DataColumnCollection SchemaProps = SchemaTable.Columns;    
 60     foreach(DataRow SchemaColumn in SchemaColumns) 
 61     { 
 62      foreach(DataColumn SchemaColumnProp in SchemaProps) 
 63      { 
 64       Console.WriteLine(SchemaColumnProp.ColumnName + "=" + SchemaColumn[SchemaColumnProp.ColumnName].ToString()); 
 65      } 
 66     } 
 67     reader.Close(); 
 68     conn.Close(); 
 69     showSplit(); 
 70 } 
 71  
 72 //************************************** 
 73 //*从数据库读取二进制数据的代码段 
 74 //*该代码段只是读取二进制的片断，不是 
 75 //*整个程序，所以不能执行，你可以把它 
 76 //*集成到你的WinForm项目里面。 
 77 //**************************************  
 78 public void getBinary() 
 79 { 
 80  /**//* 
 81  System.IO.MemoryStream stream = new System.IO.MemoryStream(); 
 82  System.IO.BinaryWriter writer = new System.IO.BinaryWriter(stream);    
 83  int BufferSize = 1024; 
 84  byte[] Buffer = new Byte[BufferSize]; 
 85  long Offset = 0; 
 86  long BytesRead = 0; 
 87  do 
 88  { 
 89   BytesRead = reader.GetBytes(2,Offset,Buffer,0,BufferSize); 
 90   writer.Writer(Buffer,0,(int)BytesRead); 
 91   writer.Flush(); 
 92   Offset += BytesRead; 
 93  } 
 94  while(BytesRead == BufferSize); 
 95  */ 
 96 } 
 97  
 98 //添加输出分隔 
 99 private void showSplit() 
100 { 
101  Console.WriteLine("\n********************************************************************\n"); 
102 } 
103  
104 public static void Main(string [] args) 
105 { 
106  SqlReader sqlreader = new SqlReader(); 
107   
108  sqlreader.basicReader(); 
109   
110  sqlreader.hasParamReader(); 
111   
112  sqlreader.hasOledbParamReader(); 
113   
114  sqlreader.outParamShow(); 
115   
116  sqlreader.multiResult(); 
117   
118  sqlreader.getSchema(); 
119 }  
120}