I was positively surprised to see a gentleman from the dutch opensource software initiative donating an amount of money to the PostgreSQL EU community.

Here are some photos:

After running configure.exe, I had to modify .qmake.cache like to following to make it work:

QMAKE_QT_VERSION_OVERRIDE = 4
LIBS           += C:\PROGRA~1\POSTGR~1\8.3\lib\libpq.lib
LIBPATH        += C:\PROGRA~1\POSTGR~1\8.3\lib
INCLUDEPATH    += C:\PROGRA~1\POSTGR~1\8.3\include
OBJECTS_DIR     = tmp\obj\debug_shared
MOC_DIR         = tmp\moc\debug_shared
RCC_DIR         = tmp\rcc\debug_shared
sql-drivers    += odbc psql
sql-plugins    += sqlite
....
....
....
QMAKE_LIBDIR_QT = $$QT_BUILD_TREE\lib

create or replace function table_drop_if_exist(tbl varchar(255)) returns void as
$$
begin
	if (select count(relname) from pg_class where relname=tbl) <> 0 then
		raise notice ‘dropping [%] with cascade’,tbl;
		execute ‘drop table ‘ || tbl || ‘ cascade’;
	end if;
end;
$$
language plpgsql;

and of course

create or replace function type_drop_if_exist(typ varchar(255)) returns void as
$$
begin
	if (select count(relname) from pg_class where relname=typ and relkind='c') <> 0 then
		raise notice ‘dropping [%] with cascade’,typ;
		execute ‘drop type ‘ || typ || ‘ cascade’;
	end if;
end;
$$
language plpgsql;

Usage:

select table_drop_if_exist('tblregion');
create table tblregion
(
	regionid integer primary key not null,
	region varchar(50),
	code varchar(2)
);

Here is an example:

CREATE  TABLE customer
(
	customer_id SERIAL NOT NULL PRIMARY KEY,
	name varchar(50)
);

When running this script, PostgreSQL automatically will create a SEQUENCE called customer_id_seq and assign the default value of the customer_id field to the next available value from the sequence. This is done by calling nextval(’customer_id_seq’::regclass).

Upon inserting new records in the customer table, the sequence will work just fine as long as you leave the customer_id field alone. In this the sequence will be incremented twice, generating numbers 1 and 2.

INSERT INTO customer (name) values('Customer 1');
INSERT INTO customer (name) values('Customer 2');

But what will happen to the next value on our sequence when we explicitly present data to the customer_id field? For example when we are loading data from an external source.

INSERT INTO customer (customer_id,name) values(3,'Customer 3');
INSERT INTO customer (customer_id,name) values(4,'Customer 4');
INSERT INTO customer (customer_id,name) values(5,'Customer 5');

As expected the value of customer_id_seq will not increment as we insert data with the example above. This is because nextval(‘customer_id_seq’) will only be triggered when customer_id is NULL.
As expected the value of customer_id_seq will not increment as we explicitly insert data with the example above. It is because nextval(‘customer_id_seq’) will only be triggered when customer_id is NULL. This means when you try to insert another customer record without explicitly providing a unique customer_id, the nextval(‘customer_id_seq’) will incremented to 3 which is already used, resulting a nice duplicate key exception:

INSERT INTO customer (name) values('Customer 6');

----------------------------------------------------------------------
ERROR:  duplicate key value violates unique constraint "customer_pkey"

********** Error **********

ERROR: duplicate key value violates unique constraint "customer_pkey"
SQL state: 23505

This can easily break your application unexpectedly. In In order to solve this problem we have to synchronize the value of customer_id_seq with the latest value existing in the customer_id column: The following function provides just the functionality needed. Just provide the table name and the the name of the identity column which the sequence is bound to.

CREATE OR REPLACE FUNCTION sync_sequence(
		table_name VARCHAR,idfield VARCHAR)
		RETURNS VOID AS
$$
DECLARE
	max_id BIGINT;
BEGIN
	-- retriving max id from table_name
	EXECUTE 'select max(' || idfield || ') from '
		|| table_name into max_id;
	-- resetting the default sequence on table_name
	EXECUTE 'alter sequence ' || table_name || '_' ||
		idfield || '_seq restart with ' || (max_id+1);
END;
$$
LANGUAGE PLPGSQL;

SELECT sync_sequence('customer','customer_id');

Have fun with PostgreSQL

PRADO unlike other PHP frameworks out there is very much like the good old ASP.NET. It is very easy to learn. Most importantly, it is supremely efficient in contrast to raw PHP. Imagine building a DataGrid component with raw PHP, or creating a form that needs to validate user input both when submit button is clicked.

PRADO makes PHP scripts, PHP applications.

<html>
  <body>
    <com:TForm>
      <com:TButton Text="Click me" OnClick="buttonClicked" />
    </com:TForm>
  </body>
</html>

class Home extends TPage
{
    public function buttonClicked($sender,$param)
    {
        // $sender refers to the button component
        $sender->Text="Hello World!";
    }
}

With a nice separation of markup and code and a resemblance to ASP.NET, having the power of PHP combined, makes PRADO the choice to develop application using
PHP language.

At the time of writing this entry PRADO version 3.1.2 released. As you might except in a modern application programming framework for web, PRADO has built-in AJAX support. Most of the standard controls (like Button, DropDown, List) are also AJAX aware.

Checkoput the PRADO website for more information.

Google SyntaxHighlighter

-- Function: new_expiredate()

-- DROP FUNCTION new_expiredate();

CREATE OR REPLACE FUNCTION new_expiredate()
  RETURNS timestamp without time zone AS
$BODY$
	select (date_trunc('month',now()) + interval '7 months')::timestamp without time zone;
$BODY$
  LANGUAGE 'sql' VOLATILE
  COST 100;
ALTER FUNCTION new_expiredate() OWNER TO postgres;

Let us look at the following scenario:

Imagine you want to enable different users on your network to access different databases on your server. Configuring every user for every permitted database in pg_hba.conf would be time consuming and less administer-friendly. The process could be simplified by allowing a certain network (or subnet) to authenticate and handle the database connection by CONNECT privilege.

In pg_hba.conf:
# Allow all network users to connect to by server.
# TYPE DATABASE USER CIDR-ADDRESS METHOD
host all all 192.168.1.0/24 password

Then secure the databases by:
-- Revoke connection right from all users to main database.
-- Dont worry, the superuser can still connect.
REVOKE CONNECT ON DATABASE postgres FROM PUBLIC;

-- create a new user called joe
CREATE ROLE joe LOGIN;

-- create a new database owned by joe.
CREATE DATABASE customers OWNER joe ENCODING UTF8

-- Revoke connection from everybody on customers database
REVOKE CONNECT ON DATABASE customers FROM PUBLIC;

-- Authorize Joe exclusively to connect to customers database
GRANT CONNECT ON DATABASE customers TO joe;

This way only Joe or anyone in that role can connect customers database.

PostgreSQL function:

create or replace function sp_category_getlist
	(plimit integer,poffset integer) returns setof category as
$$
	select *
	from
		category
        order by
		caption
	limit
		$1 offset $2
$$
language sql;

Fortunately PostgreSQL accepts NULL function arguments which in this case is treated as ALL

Example in PHP:

/* sp_filesystem_category_getlist */
public function sp_filesystem_category_getlist
	($puserid,$plimit=null,$poffset='0')
{
	$args = array($plimit,$poffset);
	$sql = "select * from sp_filesystem_category_getlist($1,$2)";
	$result=$this->query($sql,$args);
	return pg_fetch_all($result);
}