SqlDataAdapter da 和 DataSet ds 如何反复使用？

Question

SqlDataAdapter da 和 DataSet ds 如何反复使用？及：在一个查询完毕了 对另一个表进行查询C#代码如何写？

Answer 1

eg: SqlDataAdapter da = new SqlDataAdapter("select * from city where pId=@PID", conn);
            da.SelectCommand.Parameters.Add(new SqlParameter("@PID", id));
            DataSet ds = new DataSet();
            da.Fill(ds, "city");            da = new SqlDataAdapter("select * from otherTable", conn);            da.Fill(ds, "otherTable");

Answer 2

using (SqlConnection conn = new SqlConnection("server=.;uid=xxx;pwd=xxx;database=Test"))
        {
           SqlDataAdapter da = new SqlDataAdapter("select * from city where pId=@PID", conn);
            da.SelectCommand.Parameters.Add(new SqlParameter("@PID", id));
            DataSet ds = new DataSet();
            da.Fill(ds, "city");            da = new SqlDataAdapter("select * from otherTable", conn);            da.Fill(ds, "otherTable");
       }

Answer 3

顶！阿非给出了示例代码！
SqlDataAdapter,你可以理解为去数据库获取数据的搬运工，你只要告诉她去哪里搬运数据(SqlConnection对象)，以及搬运什么数据(它的SelectCommand对象所指定的sql语句，其实我们通过new SqlDataAdapter(sqlCommandText,SqlConnection)创建一个SqlDataAdapter时，就是指定了它的SelectCommand对象的命令）然后你一个Fill调用，它就去乖乖的搬运数据了，搬运回来以后，放在哪里，通过Fill方法的参数来指定，第一个参数是一个DataSet对象，就是一个数据集，你可以理解它是一个脱机的、本地内存中的数据库，既然是数据库，就能存放很多表，你每次用不同的读取数据命令，让SqlDataAdapter去搬运数据后，只要指定Fill方法中不同的第二个参数（就是表名），Fill方法就会自动将数据放在本地内存数据库的不同表之中了。

Answer 4

    protected void SqLCon()
    {
        strConstring = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
        conn = new SqlConnection();
        DataSet ds = new DataSet();
        try
        {  
            conn.ConnectionString = strConstring;
            conn.Open();
            
            da = new SqlDataAdapter("select ZhType from 帐户类别", conn);
            da.Fill(ds);            DropDownList32.Items.Clear();
            DropDownList32.DataTextField = "ZhType";
            DropDownList32.DataValueField = "ZhType";
            DropDownList32.DataSource = ds;
            DropDownList32.DataBind();
            DropDownList32.SelectedValue = "";
            DropDownList32.SelectedIndex = 0;
            strTypeVal = DropDownList32.SelectedItem.Text;
 
            DropDownList33.Items.Clear();
            DropDownList33.DataTextField = "ZhType";
            DropDownList33.DataValueField = "ZhType";
            DropDownList33.DataSource = ds;
            DropDownList33.DataBind();
            DropDownList33.SelectedValue = "";
            DropDownList33.SelectedIndex = 0;
            strTypeVal = DropDownList33.SelectedItem.Text;     
       
            da.= new SqlDataAdapter("select distinct(sheng) from 地名表", conn);
            da.Fill(ds);
            
            DropDownList2.Items.Clear();
            DropDownList2.DataTextField = "sheng";
            DropDownList2.DataValueField = "sheng";
            DropDownList2.DataSource = ds;
            DropDownList2.DataBind();
        }
        finally
        {
            conn.Close();
            conn.Dispose();
        }
    }编译错误 
说明: 在编译向该请求提供服务所需资源的过程中出现错误。请检查下列特定错误详细信息并适当地修改源代码。 编译器错误消息: CS1001: 应输入标识符源错误: 行 114:            strTypeVal = DropDownList33.SelectedItem.Text;     
行 115:       
行 116:            da.= new SqlDataAdapter("select distinct(sheng) from 地名表", conn);
行 117:            da.Fill(ds);
行 118:            
 源文件: f:\text\4\ZcwWebApp\ZcwWebApp\Login.aspx.cs    行: 116 如何处理？？

Answer 5

修改为：
protected void SqLCon()
    {
        strConstring = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
        conn = new SqlConnection();
        DataSet ds = new DataSet();
        try
        {  
            conn.ConnectionString = strConstring;
            conn.Open();
            
            da = new SqlDataAdapter("select ZhType from [帐户类别]", conn);
            da.Fill(ds,"aaa");            DropDownList32.Items.Clear();
            DropDownList32.DataTextField = "ZhType";
            DropDownList32.DataValueField = "ZhType";
            DropDownList32.DataSource = ds.Tables["bbb"];
            DropDownList32.DataBind();
            DropDownList32.SelectedValue = "";
            DropDownList32.SelectedIndex = 0;
            strTypeVal = DropDownList32.SelectedItem.Text;
 
            DropDownList33.Items.Clear();
            DropDownList33.DataTextField = "ZhType";
            DropDownList33.DataValueField = "ZhType";
            DropDownList33.DataSource = ds;
            DropDownList33.DataBind();
            DropDownList33.SelectedValue = "";
            DropDownList33.SelectedIndex = 0;
            strTypeVal = DropDownList33.SelectedItem.Text;     
       
            da.= new SqlDataAdapter("select distinct(sheng) from [地名表]", conn);
            da.Fill(ds,"bbb");
            
            DropDownList2.Items.Clear();
            DropDownList2.DataTextField = "sheng";
            DropDownList2.DataValueField = "sheng";
            DropDownList2.DataSource = ds.Tables["bbb"];
            DropDownList2.DataBind();
        }
        finally
        {
            conn.Close();
            conn.Dispose();
        }
    }

Answer 6

protected void SqLCon()
    {
        strConstring = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
        conn = new SqlConnection();
        DataSet ds = new DataSet();
        try
        {  
            conn.ConnectionString = strConstring;
            conn.Open();
            
            da = new SqlDataAdapter("select ZhType from [帐户类别]", conn);
            da.Fill(ds,"aaa");            DropDownList32.Items.Clear();
            DropDownList32.DataTextField = "ZhType";
            DropDownList32.DataValueField = "ZhType";
            DropDownList32.DataSource = ds.Tables["bbb"];
            DropDownList32.DataBind();
            DropDownList32.SelectedValue = "";
            DropDownList32.SelectedIndex = 0;
            strTypeVal = DropDownList32.SelectedItem.Text;
 
            DropDownList33.Items.Clear();
            DropDownList33.DataTextField = "ZhType";
            DropDownList33.DataValueField = "ZhType";
            DropDownList33.DataSource = ds;
            DropDownList33.DataBind();
            DropDownList33.SelectedValue = "";
            DropDownList33.SelectedIndex = 0;
            strTypeVal = DropDownList33.SelectedItem.Text;     
       
            da.= new SqlDataAdapter("select distinct(sheng) from [地名表]", conn);
            da.Fill(ds,"bbb");
            
            DropDownList2.Items.Clear();
            DropDownList2.DataTextField = "sheng";
            DropDownList2.DataValueField = "sheng";
            DropDownList2.DataSource = ds.Tables["bbb"];
            DropDownList2.DataBind();
        }
        finally
        {
            conn.Close();
            conn.Dispose();
        }
    }

Answer 7

纠正：
  DropDownList32.DataSource = ds.Tables["bbb"];
===》
  DropDownList32.DataSource = ds.Tables["aaa"];

Answer 8

 SqlDataAdapter da = new SqlDataAdapter("select * from city where pId=@PID", conn);
            da.SelectCommand.Parameters.Add(new SqlParameter("@PID", id));
            DataSet ds = new DataSet();
            da.Fill(ds, "city");            da = new SqlDataAdapter("select * from otherTable", conn);            da.Fill(ds, "otherTable");

Answer 9

using (SqlConnection conn = new SqlConnection("server=.;uid=xxx;pwd=xxx;database=Test"))
        {
           SqlDataAdapter da = new SqlDataAdapter("select * from city where pId=@PID", conn);
            da.SelectCommand.Parameters.Add(new SqlParameter("@PID", id));
            DataSet ds = new DataSet();
            da.Fill(ds, "city");            da = new SqlDataAdapter("select * from otherTable", conn);            da.Fill(ds, "otherTable");
       }