convert datareader to dataset vb

... 5.3 Converting a DataReader to a DataSet Problem You need to transfer data from a DataReader to a DataSet. Solution Create a DataTable schema in the destination DataSet using the schema information ... method that converts a DataReader to a DataSet, this method is declared protected and cannot be accessed (unless you write a custom DataAdapter). There is no built-in mechanism for converting ... the GetSchemaTable( ) method of the DataReader. Then, use the GetData( ) method of the DataReader to load each row of data into an array of objects, and add it to the DataTable using the Add(...

Ngày tải lên: 07/11/2013, 13:15

... aren’t able to first reduce the num- ber of ADO.NET-managed rows, you might wish to consider alternatives to LINQ to DataSet. LINQ to Entities, discussed in Chapter 19, “Using LINQ to Entities,” ... DataAdapter to load data, call its Fill method before using LINQ to extract data. Note The DataAdapter object’s Fill method loads all requested data into local DataSet memory. If the tables you need to ... = From cu In Customer.AsEnumerable() Select CustomerName = cu.Field(Of String)("FullName") Order By CustomerName Dwonloaded from: iDATA.ws Chapter 18 Using LINQ to DataSet After completing...

Ngày tải lên: 03/10/2013, 00:20

... datab_0; datab_1; datab_2 là các số 11 bit có dấu; 2. KHỐI CONVERT YCRCB TO RGB 2.1SƠ ĐỒ KHỐI Hình 11.1: Sơ đồ của khối Convert YCrCb to RGB Tên Mô tả CLK Xung clock 27Mhz từ kit DE2. RESET Reset ... oRequest = ( ( H_Cont >= H_BLANK && H_Cont < H_TOTAL ) && ( V_Cont>=V_BLANK && V_Cont<V_TOTAL ) ); //tính to n vị trí X,Y của Pixel trong frame (X : vị trí pixel ... ; Do các hệ số có dạng thập phân, trong khi đó các phép to n của phần cứng được tổng hợp chỉ thực hiện trên số nguyên nên khi làm tròn và tính to n thì sai số khá lớn, vì vậy ta phải nhân biểu thức...

Ngày tải lên: 04/10/2013, 00:20

Ngày tải lên: 07/07/2014, 16:00

Ngày tải lên: 09/07/2014, 06:00

Ngày tải lên: 09/09/2013, 17:10

Ngày tải lên: 26/10/2013, 21:20

Ngày tải lên: 26/10/2013, 21:20

Ngày tải lên: 26/10/2013, 21:20

Ngày tải lên: 26/10/2013, 21:20

... Team LiB ] Recipe 5.2 Copying Tables from One DataSet to Another Problem You need to copy an existing schema and data from one DataSet to another. Solution Use one of the following techniques: ... the Orders table is bound to a data grid on the form. Copy Button.Click Creates a destination DataSet and copies the schema and specified data into it from the source DataSet created in the Form.Load ... source DataSet are copied to the destination. This is accomplished by iterating over the collection of tables in the source DataSet and using the Copy( ) method of each DataTable object to copy...

Ngày tải lên: 28/10/2013, 18:15

... Converting a DataSet to an ADO Recordset Problem You need to convert a DataSet to an ADO Recordset so that you can use it in a legacy application. Solution You must persist the DataSet to ... used to transform the XML document output by the DataSet into an ADO Recordset XML document. The sample code contains one event handler and one method: Go Button.Click Converts the DataSet to ... A DataReader accesses the schema information for the data to convert using the GetSchemaTable( ) method. This information is mapped to and added to the ADO Recordset XML document. 3. The DataSet...

Ngày tải lên: 14/12/2013, 18:16

... File That Shows Changes Made to a DataSet Problem When you use the GetXML( ) method of the DataSet, you may see only the current values in the DataSet. You want to get the original values and ... modifications made to a DataSet. The sample code contains two event handlers and a single method: Form.Load Sets up the sample by loading the Categories table from Northwind into a DataSet and ... written for the DataSet by specifying an XmlWriteMode of DiffGram when calling the WriteXml( ) method of the DataSet. The GetXml( ) method cannot be used to generate a DiffGram. A DataSet can be...

Ngày tải lên: 21/01/2014, 11:20

... library stocked with tools for everything from sending e-mail to encrypting a password. To master ASP.NET, you need to learn about each of these ingredients. This book covers all these topics from ... learning curve. Not only do you need to learn how to use an advanced design tool (Visual Studio) and a toolkit of objects (the .NET Framework), you also need to master a pro- gramming language ... sometimes used in a narrow sense to refer to the portion of the .NET class library used to design web pages. On the other hand, ASP.NET also refers to the whole topic of .NET web applications,...

Ngày tải lên: 24/01/2014, 08:20

... Create Button.Click This event handler calls the CreateData( ) method to add random data to the DataSet. Modify Button.Click This event handler makes random changes to the data in the DataSet: ... CreateData( ) method is called to create new data. • The UpdateData( ) method is called to update all of the changes made to the DataSet with the data source. Delete Button.Click This event handler ... updating a DataSet with a many -to- one relationship is shown in data source. Refresh Button.Click This event handler clears all data from the DataSet. LoadData( ) is then called to load all...

Ngày tải lên: 26/01/2014, 10:20

... [ Team LiB ] Recipe 8.6 Using XPath to Query Data in a DataSet Problem You need to use an XPath expression to extract certain rows from a DataSet. Solution Use SelectSingleNode( ) ... to access the XmlDataDocument to perform certain functionality more conveniently than could be accomplished using the DataSet directly. To execute an XPath query against the contents of a DataSet, ... by creating a DataSet containing the Orders table and Order Details table from Northwind and a nested relation between the two tables. Go Button.Click Executes an XPath query to retrieve the...

Ngày tải lên: 26/01/2014, 10:20

... private void writeSchemaButton_Click(object sender, System.EventArgs e) { DataSet ds = new DataSet( ); SqlDataAdapter da; // Fill the Order table and add it to the DataSet. da = new SqlDataAdapter("SELECT ... try { // Read the schema into the DataSet. DataSet ds = new DataSet( ); ds.ReadXmlSchema(xtr); // Bind the default view of the Orders table to the grid. resultDataGrid.DataSource ... id="NewDataSet" xmlns="" [ Team LiB ] Recipe 8.1 Using XSD Schema Files to Load and Save a DataSet Structure Problem You need to create an XSD schema from a DataSet and...

Ngày tải lên: 26/01/2014, 10:20

Ngày tải lên: 14/03/2014, 23:20

Ngày tải lên: 14/03/2014, 23:20

Ngày tải lên: 19/03/2014, 13:36