dim ds as new dataset  

dim daNew as new oledb.oledataadapter

  daNew.fillshema(ds)

Dim ds As New DataSet
Dim da As New SqlDataAdapter ("Select * From users", Conn)
da.Fill (ds, "Users"
Me.DataGrid1.DataSource = ds.Tables("Users"

Клас имеет свойство: Item(таблица, ID_строки)

При Set(value) - используя подобний механизм обновить дание, здесь Value строка для обновления типа "Ячейка1*Ячейка2*Ячейка3"

Клас нужен для упрощения основних операций с БД при разработке клиента не используя при этом промежуточний DataSet.

dataset.wtiteXMLshema("dataset.xsd"

gemrroinoe sozdanie tipizirovannogo dataset.

В дизайнере есть Generate DataSet после этого появляется подходящий ДатаСет, а програмно?

 Working with strong typed datasets

This example will show how to use a strong typed dataset generated with xsd. To do so, we need a .xsd file specifing the schema to the strong dataset. You can generate this file by hand, or you can use xsd to generate it for you. To have xsd generate the .xsd for you, you have to suppy it with a .xml file which it will infer the .xsd from. We can use a .xml file generated with a DataAdapter.WriteXml() method:

public void GenerateXmlFromDataSet(NpgsqlConnection conn)
{
conn.Open();


NpgsqlDataAdapter da = new NpgsqlDataAdapter("select * from tablea", conn);

DataSet ds = new DataSet();

da.Fill(ds);

ds.WriteXml("StrongDataSetFeed.xml";
}

This will give us a file which looks similar to this:

<?xml version="1.0" standalone="yes"?>
<NewDataSet>
  <Table>
    <field_serial>1</field_serial>
    <field_text>Random text</field_text>
  </Table>
  <Table>
    <field_serial>2</field_serial>
    <field_int4>4</field_int4>
  </Table>
  <Table>
    <field_serial>3</field_serial>
    <field_int8>8</field_int8>
  </Table>
  <Table>
    <field_serial>4</field_serial>
    <field_bool>true</field_bool>
  </Table>
  <Table>
    <field_serial>5</field_serial>
    <field_text>Text with ' single quote</field_text>
  </Table>
</NewDataSet>

This file will be used with xsd to generate the .xsd file with the following command:

xsd StrongDataSetFeed.xml

xsd will produce an xml schema which will have all types specified as string, we just change the xsd to use the correct types and have a .xsd file similar to this:

<?xml version="1.0" encoding="utf-8"?>
<xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
  <xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:Locale="pt-BR">
    <xs:complexType>
      <xs:choice maxOccurs="unbounded">
        <xs:element name="Table">
          <xs:complexType>
            <xs:sequence>
              <xs:element name="field_serial" type="xs:int" minOccurs="0" />
              <xs:element name="field_text" type="xs:string" minOccurs="0" />
              <xs:element name="field_int4" type="xs:int" minOccurs="0" />
              <xs:element name="field_int8" type="xs:long" minOccurs="0" />
              <xs:element name="field_bool" type="xs:boolean" minOccurs="0" />
            </xs:sequence>
          </xs:complexType>
        </xs:element>
      </xs:choice>
    </xs:complexType>
  </xs:element>
</xs:schema>

With this file we issue the following command to have xsd generate the strong dataset:

xsd StrongDataSetFeed.xsd /dataset

Which will generate a file we can compile to get an assembly with the strong dataset. To use it, we do the following:

using System;
using Npgsql;


public class t
{
public static void Main(String[] args)
{
NpgsqlConnection conn = new NpgsqlConnection("Server=127.0.0.1;Port=5432;User Id=joe;Password=secretatabase=joedata;";

conn.Open();

NpgsqlDataAdapter da = new NpgsqlDataAdapter("Select * from tablea", conn);


NewDataSet n = new NewDataSet();

da.Fill(n);

foreach (NewDataSet._TableRow tr in n._Table)
{
Console.WriteLine(tr.field_serial);
}
}
}