我想将此DataSet代码更改为SqlDataReader代码

Question

此代码实际上是用数据集方法编写的。 它工作正常。但我想将其改为datareader方法。

public DataSet SelectTopic(LessionPlanBEL bellp) 
{ 
    DataSet ds = new DataSet(); 
    try 
    { 
     con.Open(); 
     string query = "Select * from lessiontopic where subject=@subject "; 
     SqlDataAdapter da = new SqlDataAdapter(query, con); 
     da.SelectCommand.Parameters.Add("@subject", SqlDbType.Int).Value = bellp.subject; 


     da.Fill(ds); 
    } 
    catch (Exception ex) 
    { 

    } 
    finally 
    { 
     con.Close(); 
    } 
    return ds; 
} 

Answer 1

试试这个

public DataSet SelectTopic(LessionPlanBEL bellp) 
      { 
       SqlDataReader dr = new SqlDataReader(); 
       SqlCommand cmd; 
       try 
       { 
        con.Open(); 
        cmd =new SqlCommand("Select * from lessiontopic where subject=@subject ",conn); 

        cmd.Parameters.AddWithValue("@subject", bellp.subject.ToString()); 
    dr=cmd.ExecuteReader(); 
       } 
       catch (Exception ex) 
       { 

       } 
       finally 
       { 
        con.Close(); 
       } 

      }