START WITH and CONNECT BY in Oracle SQL

The start with .. connect by clause can be used to select data that has a hierarchical relationship
 (usually some sort of parent->child (boss->employee or thing->parts).

We'll see a simple example to understand this,

create table test_connect_by (
  parent     number,
  child      number,
  constraint uq_tcb unique (child)
);


insert into test_connect_by values ( 5, 2);
insert into test_connect_by values ( 5, 3);
Parent = 5
Child = 2,3

insert into test_connect_by values (15,10);
insert into test_connect_by values (15, 5);
Parent = 15
Child = 10,5

insert into test_connect_by values (17, 9);
insert into test_connect_by values (17, 8);
Parent = 17
Child = 9,8

insert into test_connect_by values (38,15);
insert into test_connect_by values (38,17);
Parent = 38
Child = 15,17

insert into test_connect_by values (26, 1);
insert into test_connect_by values (26,12);
Parent = 26
Child = 1,12

insert into test_connect_by values (null, 38);
insert into test_connect_by values (null, 26);
Parent = null
Child = 38,26


Query:

select lpad(' ',2*(level-1)) || to_char(child) s
  from test_connect_by
  start with parent is null
  connect by prior child = parent;

Output:


38
   15
      10
       5 
   17
     9
     8
26
   1
   12

Redirecting non www URL to www URL

If you type yahoo.com in browser it will be redirected to www.yahoo.com.
If you want to do same with your website then put the following code to .htaccess file.

CODE:
RewriteEngine On
RewriteCond %{HTTP_HOST} ^optimaxwebsolutions\.com$
RewriteRule (.*) http://www.optimaxwebsolutions.com/$1 [R=301,L]

Where $1 is the first argument kind of thing like for example if you want to redirect

http://drupal.com/user => http://www.drupal.com/user .

Rewriting URL's with .htaccess

Rewriting product.php?id=12 to product-12.html

It is a simple redirection in which .php extension is hidden from the browser’s address bar and dynamic url (containing “?” character) is converted into a static URL.

RewriteEngine on
RewriteRule ^product-([0-9]+)\.html$ product.php?id=$1

For more reference on this refer:
http://roshanbh.com.np/2008/03/url-rewriting-examples-htaccess.html

Setting up a Cron tab in Linux:

Linux Crontab Format
MIN HOUR DOM MON DOW CMD

Example for scheduling a job for 10th June 08:30 AM

30 08 10 06 * /home/ramesh/full-backup

    * 30 – 30th Minute
    * 08 – 08 AM
    * 10 – 10th Day
    * 06 – 6th Month (June)
    * * – Every day of the week

For further more details on setting up Cron tabs and viewing the cron tab entries you can refer:

http://www.thegeekstuff.com/2009/06/15-practical-crontab-examples

Writing to a Remote file using FTP functions

$file_name = "data.txt";
$fp = fopen ( $file_name, 'r' );
if ($fp) {
  $data = fread ( $fp, filesize ( $file_name ) );
  fclose ( $fp );
  $file_name = "ftp://user:pass@ftp.somedomain.com/home/user/$file_name";
  $fp = fopen ( $file_name, 'wt' );
  if ($fp) {
    echo 'writing data';
    fwrite ( $fp, $data );
    fclose ( $fp );

  }
}

Autosave - Drupal module

The Autosave module automatically saves a snapshot of your content type form using AJAX. If the user's browser or machine dies while editing a node; the edits will be presented to the user the next time they return to the node. The user may toggle back and forth between the last saved version and the version with the edits that were lost and select which of these they would like to continue with.

This is a very useful module in situations like when your machine is corrupted before saving your article or news in these situations this module will have the backup of your content.

You can find this at : http://drupal.org/project/autosave

Database tweaks - Drupal module

This module allow you to enable and change following settings in database:

- SQL_BIG_SELECTS
- MAX_JOIN_SIZE
- MAX_ALLOWED_PACKET
- WAIT_TIMEOUT

and changing SQL_MODES.

This module is very useful in situations like, when the DB is overloaded with too many fields in CCK or very big queries (cache queries) it will throw "mysql gone away" error in drupal. This is actually a common error in these situations. The Fix is we need to increase the Packet size in my.cnf or my.ini file in Mysql folder. But in situations like if in Live sites where we don't have access to these files "my.cnf" if the error comes it will be difficult to handle in those situations you can use this module.

You can find the module at : http://drupal.org/project/db_tweaks

Drupal for Firebug - Drupal module

Drupal for Firebug module:

This module is a helper module for a customized Firefox plugin that displays Drupal debugging and SQL query information. Very Useful module, to checkout the node contents you don't need to put node_load or some functions like this module will load and display all the Node properties and Values through Firebug.

You can find the module at : http://drupal.org/project/drupalforfirebug.

Taxonomy Functions

Avoid queries to display the content which are associated with a particular taxonomy term or vocabulary.
Try Using the taxonomy related functions like ,
1. taxonomy_get_children
-- Find all children of a term ID.
2. taxonomy_get_parents
-- Find all parents of a given term ID.
3. taxonomy_get_parents_all
-- Find all ancestors of a given term ID.
4. taxonomy_get_related
-- Find all term objects related to a given term ID.
5. taxonomy_get_term
-- Return the term object matching a term ID.
6. taxonomy_get_term_by_name
-- Try to map a string to an existing term, as for glossary use.
7. taxonomy_get_tree
-- Create a hierarchical representation of a vocabulary.
8. taxonomy_node_get_terms
-- Find all terms associated with the given node, ordered by vocabulary and term weight.