ADO.NET 学习笔记

1、连接到 SQL Server：

   
     

    
      
    
      //
    
       Assumes connectionString is a valid connection string.
    
      

    
      using
    
       (SqlConnection connection 
    
      =
    
       
    
      new
    
       SqlConnection(connectionString))
{
 connection.Open();
 
    
      //
    
       Do work here.
    
      

    
      }

   
     

 

2、执行命令 (ADO.NET)

 

下面的代码示例演示如何创建 SqlCommand 对象以通过设置其属性执行存储过程。 SqlParameter 对象用于指定存储过程的输入参数。 使用 ExecuteReader 方法执行此命令，并在控制台窗口中显示 SqlDataReader 的输出。

 

代码

    
      

     
       
     
       static
     
        
     
       void
     
        GetSalesByCategory(
     
       string
     
        connectionString, 
     
       string
     
        categoryName)
{
 
     
       using
     
        (SqlConnection connection 
     
       =
     
        
     
       new
     
        SqlConnection(connectionString))
 {
 
     
       //
     
        Create the command and set its properties.
     
       

     
        SqlCommand command 
     
       =
     
        
     
       new
     
        SqlCommand();
 command.Connection 
     
       =
     
        connection;
 command.CommandText 
     
       =
     
        
     
       "
     
       SalesByCategory
     
       "
     
       ;
 command.CommandType 
     
       =
     
        CommandType.StoredProcedure;

 
     
       //
     
        Add the input parameter and set its properties.
     
       

     
        SqlParameter parameter 
     
       =
     
        
     
       new
     
        SqlParameter();
 parameter.ParameterName 
     
       =
     
        
     
       "
     
       @CategoryName
     
       "
     
       ;
 parameter.SqlDbType 
     
       =
     
        SqlDbType.NVarChar;
 parameter.Direction 
     
       =
     
        ParameterDirection.Input;
 parameter.Value 
     
       =
     
        categoryName;

 
     
       //
     
        Add the parameter to the Parameters collection. 
     
       

     
        command.Parameters.Add(parameter);

 
     
       //
     
        Open the connection and execute the reader.
     
       

     
        connection.Open();
 SqlDataReader reader 
     
       =
     
        command.ExecuteReader();

 
     
       if
     
        (reader.HasRows)
 {
 
     
       while
     
        (reader.Read())
 {
 Console.WriteLine(
     
       "
     
       {0}: {1:C}
     
       "
     
       , reader[
     
       0
     
       ], reader[
     
       1
     
       ]);
 }
 }
 
     
       else
     
       
 {
 Console.WriteLine(
     
       "
     
       No rows found.
     
       "
     
       );
 }
 reader.Close();
 }
}