Technology Questions

The XML DOM (document object model) is used the access and management of xml. It is a platform that is language neutral and allows a program or a script to dynamically access a document. It also allows the updation of content as well as the structure and style of the document. It is responsible for the defining of the object and properties of all xml elements as well as to define the methods for their access. There are various methods that can be used in xml dom such as:

- getElementsByTagName: used to call a specific user defined tag.

- setAttribute: used to change the value of an existing attribute.

- appendChild: used to add a child node to another node.

SELECT * FROM table_name ORDER BY column_name desc Fetch first 5 rows only;

setcookie('variable','value','time');
variable - name of the cookie variable
value     - value of the cookie variable
time       - expiry time

Example:
<?php
setcookie('Test',$i,time()+3600);
?>
Test - cookie variable name
$i - value of the variable 'Test'
time()+3600 - denotes that the cookie will expire after an one hour

LSMW is widely used by EDI programmers. EDI Programmers connect the SAP system to Non SAP system. During this Data migration is a necessity. When data migrates from source to destination the destination code is differrent from the source code. So what LSMW does is 

* Converts the data in to batch files

* Then converts the batch files in to source code batch files 

* And then mirgates data. Standard Interfaces like BAPI or Idoc are used in this process.

A prompt box allows the user to enter input by providing a text box.

A cookie is a small text file on the client machine either in the client’s file system or memory of client browser session.

'ViewState' is specific to a page in a session.
'SessionState' is specific to user specific data that can be accessed across all pages in the web application.

Both these are used to combine the results of different SELECT statements.

    UNION       - Selects only distinct values 

    UNION ALL - Selects duplicate values also

Syntax:

    SELECT column_name(s) FROM table1

    UNION / UNION ALL

    SELECT column_name(s) FROM table2;

Notice that each SELECT statement within the UNION must have the same number of columns. The columns must also have similar data types. Also, the columns in each SELECT statement must be in the same order.