DataReader、DataSet、DataView循环读取整表或单列

代码

   
     

    
      string
    
       sql 
    
      =
    
       
    
      "
    
      delete from Users where ID=3
    
      "
    
      ;
 SqlConnection conn 
    
      =
    
       
    
      new
    
       SqlConnection(sqlConnString);
 SqlCommand cmd 
    
      =
    
       
    
      new
    
       SqlCommand(sql, conn);
 
    
      try
    
      
 {
 conn.Open();
 sqldataReader dr
    
      =
    
      cmd.ExecutReader();

 
    
      while
    
      (dr.Reader())

 {

 responser.write(dr[
    
      "
    
      Name
    
      "
    
      ]);

 }

 }
 
    
      catch
    
       (SqlException sqlex)
 {
 Response.Write(sqlex.Message 
    
      +
    
       
    
      "
    
      <br>
    
      "
    
      );
 }
 
    
      finally
    
      
 {
 conn.Close();
 }


    
      2
    
      、DataAdapter和DataSet、DataView读取单列数据


    
      string
    
       sql 
    
      =
    
       
    
      "
    
      select * from Users
    
      "
    
      ;
 SqlConnection conn 
    
      =
    
       
    
      new
    
       SqlConnection(sqlConnString);
 SqlDataAdapter da 
    
      =
    
       
    
      new
    
       SqlDataAdapter(sql, conn);
 
    
      try
    
      
 {
 conn.Open();
 DataSet ds 
    
      =
    
       
    
      new
    
       DataSet(
    
      "
    
      Users
    
      "
    
      );
 da.Fill(ds, 
    
      "
    
      Users
    
      "
    
      );
 DataView dv 
    
      =
    
       ds.Tables[
    
      0
    
      ].DefaultView;

 
    
      //
    
      DataView读取单列
    
      

    
       
    
      for
    
       (
    
      int
    
       i 
    
      =
    
       
    
      0
    
      ; i 
    
      <
    
       dv.Table.Rows.Count; i
    
      ++
    
      )
 {
 Response.Write(dv.Table.Rows[i][
    
      "
    
      ID
    
      "
    
      ].ToString()
    
      +
    
      "
    
       
    
      "
    
      +
    
      "
    
      <br>
    
      "
    
      );
 }

 
    
      //
    
      DataSet读取单列
    
      

    
       
    
      foreach
    
       (DataRow row 
    
      in
    
       ds.Tables[
    
      0
    
      ].Rows)
 Response.Write(row[
    
      "
    
      Name
    
      "
    
      ].ToString()
    
      +
    
      "
    
       
    
      "
    
      +
    
      row[
    
      0
    
      ].ToString()
    
      +
    
      "
    
      <br>
    
      "
    
      );
 DataList1.DataSource 
    
      =
    
       dv;
 DataList1.DataBind();
 GridView1.DataSource 
    
      =
    
       ds;
 GridView1.DataBind();
 }
 
    
      catch
    
       (SqlException exception)
 {
 Response.Write(exception.Message 
    
      +
    
       
    
      "
    
      <br>
    
      "
    
      );
 }
 
    
      finally
    
      
 {
 conn.Close();
 }
   
     

 

 

循环读取dataset

代码

   
     

    
      
    
      DataSet ds 
    
      =
    
       
    
      new
    
       DataSet();

 
    
      foreach
    
       (DataTable dt 
    
      in
    
       ds.Tables)
 {
 
    
      foreach
    
       (DataRow dr 
    
      in
    
       dt.Rows)
 {
 
    
      foreach
    
       (DataColumn dc 
    
      in
    
       dt.Columns)
 {
 System.Console.Write(dr[dc]);
 }
 }
 }