ASP.NET PDF Viewer using C#, VB/NET

Both page and control events are executed on the server, so when they are triggered, the parent page along with its view state is posted to the server, where the event is handled and a response (the same or another page) is sent back to the client A so-called postback occurs if a page posts information to the server requesting the same page back This round-trip scenario is quite common: the Reload button in Listing 14-2 or the Generate button from Listing 14-4 are both examples of triggering a postback In both of these cases, we have a postback because we remain on the same page; for example, the originating page handles the data submission by updating the content of a label (an HTML <span> element) in the button click handler More often, though, data is posted to another page, in which case it is referred to as cross-page posting.

qr code generator vb net, winforms barcode, winforms code 128, vb.net ean 128, vb.net generate ean 13, vb.net pdf417 free, c# remove text from pdf, pdfsharp replace text c#, vb.net data matrix, c# remove text from pdf,

A quick select verifies that the procedure invocation was successful (recall that we inserted the passed array into the table varchar_varray_table in the procedure): benchmark@ORA10G> select * from varchar_varray_table; VARRAY_COLUMN --------------------------------------VARRAY_OF_VARCHARS('elem 1', 'elem 2') In the next section, we examine how we can use PreparedStatement in conjunction with the ARRAY class to materialize a collection of built-in types.

A UDF can only read data Updates of any kind are not allowed A UDF can return only a scalar value A UDF can be invoked from nearly anywhere within a T-SQL query The last point highlights the primary reason why you might choose a UDF over a stored procedure A stored procedure works best as a monolithic, atomic module that encapsulates all the data interaction required for a given request In fact, a stored procedure is somewhat analogous to a service interface, in that a stored procedure typically sits at the data layer boundary and serves as the interface between the data tier and the middle tier On the other hand, UDFs are more analogous to components, in that they are intended to implement small, but useful, tasks that can be reused within queries as a part of a larger task.

You can easily enable crosspage posting by setting the PostBackUrl property of the submitting control For instance, a SayHello button could be declared as follows: <asp:Button ID="btnSayHello" runat="server" Text="Greet" PostBackUrl="SayItaspx" /> There is a significant difference between how data submissions are handled via postback and cross-page posting: whereas the former is done in the submitting control s click event handler (for example, Reload_Click in the timer example), with cross-page posting the submission event is handled in the Load event handler of the page to which the postback URL points What slightly complicates matters is that the form data submitted is not available directly on the receiving page, but instead you have to reference it through the PreviousPage property of the page.

This section shows how to select a varray of built-in data types from the database using the ARRAY class. This process involves the following steps: 1. Prepare and execute the statement. This is the familiar step of preparing and executing a select statement that selects the Collection object. 2. Retrieve the ARRAY object from the ResultSet. In this step, we use the getArray() method on the ResultSet object to retrieve the ARRAY object. Note that if no rows are selected, we get a null ARRAY object returned. 3. Retrieve individual elements from the ARRAY object. Finally, we retrieve individual array elements. We will demonstrate the case of retrieving the array of varchar2 (varray_of_varchars type) and array of number (varray_of_numbers) separately. To retrieve the individual collection elements, we can use either the standard method getArray() of the Array interface, or one of the two methods getResultSet() or getOracleArray() of the ARRAY class. For numeric collections, we can, in addition to the aforementioned methods, use one of the many numeric extension methods (such as getIntArray()). Choosing between these methods is, to a large extent, a matter of convenience, although there are some performance implications as well. We will examine these methods along with examples shortly. The following sections detail each of these steps as part of the explanation of the class DemoQueryingCollectionOfBuiltInTypes presented here: /** This program demonstrates how to select a collection of built-in types * into JDBC (we use varray of varchar2 and varray of number * to demonstrate the concepts). * COMPATIBLITY NOTE: * runs successfully against 9.2.0.1.0 and 10.1.0.2.0 */ import java.math.BigDecimal; import java.sql.SQLException; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.Types; import java.sql.ResultSet;