Elzo Valugi » SQL

Oracle Strategic Product?

elzo valugi — Sun, 08 Nov 2009 15:21:40 +0000

This is pretty silly. This Oracle form is really silly. By what logic someone in those forbidden condition will stop downloading this beta product? If you are from Cuba and US has prohibited export to your country but the website allows you to download, what will you do? How can one check if is on Specially Designated Terrorists or Designated Narcotic Traffickers lists?

In terms of web usability this form is futile for 99% of the people accessing it and the rest 1% that are terrorists, Cubans or narcotic traffickers will not really care about complying with its demands.

SO?

PHP Barcelona 2009 impressions

elzo valugi — Sat, 07 Nov 2009 17:48:04 +0000

Last Friday and Saturday I was attending PHP Barcelona Conference. Barcelona is a TOP10 tourist destination but when it comes to PHP we are a small province town, and as you may suspect Gaudi and beaches are somehow more famous here than programmers. But we exist and most of us try to do their best and this happens thanks to Barcelona PHP Programmers Group.

The program had enough presentation to choose from.

These are the presentations that I’ve attended:
Working with Web Services – by Lorna Mitchell, not bad but very basic. Probably good for PHP programmers who never worked with an API or webservice before. Alex Puig presentation about actually implementing an API was far more interesting.

Trees in Database – by Lorenzo Alberton. This one was better even though it wasn’t a PHP subject. I already knew and implemented some of this advanced data models, but not all. Interesting.

Simple is Hard – by Rasmus Lerdorf. Good. I love people that tell me I am stupid.
http://talks.php.net/show/phpbcn

Ajax for scalability by Erik Schultink from Tuenti. Good advices but nothing different from Facebook presentations seen on InfoQ and good only if you have the site with most traffic in your country .

Agile Development with PHP in Practice by Lars Jankowfsky. Basic.

I’ve also been to an Oracle on PHP workshop. Database Resident Connection Pool on 11g seems interesting.

PHP Security Audits – by Seguy Damien. Very clear and nice. Give me and Andrea something to discuss. I think I should do PHP and Javascript audits. Not only security but also code improvements.

The overall organization was good. Food and drinks, books with discounts.

The State of QA Tools for PHP by Sebastian Bergmann. Probably one of the most interesting presentations of the conference.

I did attend to a Phing seminar I think it is a pretty useful tool that I cant wait to test.

PDO charset problems

elzo valugi — Thu, 28 Aug 2008 10:29:36 +0000

These are the problems of the world before PHP6. Soon to be forgotten.
I was working in my application with different charsets, like slavic (cyrillic), japanese or arabic and in the database all was peachy and the localized information was stored correctly under utf8_unicode_ci encoding. The problem was that the php received and printed wrong information, like question marks or squares or strange chars, and this usually happens when the headers are not set properly which was not the case.

I am using PDO as the abstraction layer in this project, and it appears that you have to specificly state your pdo connection what type of encoding you want for transfer.

$db->query('SET NAMES UTF8');

For mysqli

$mysqli->query("SET NAMES 'utf8'");

This simple line in the connection part solve it all. Actually this is not even a PDO thing, is a mySQL thing; in this case we instruct the server and the client what encoding to use in the communication.

This is more a workaround, because the communication should be done depending on the _default-character-set_ variable from mysql ini file. There are several bugs related with this problem in php and mysql bug zoo.

Como calcular cuantas dias del dia X – sintaxa de SQL

elzo valugi — Sun, 24 Jun 2007 21:20:12 +0000

Como se puede calcular el numero de dias a partir de una fecha existente en un campo de tipo DATE o DATETIME. In esto exemplo el campo es created_date.

1. La primera version:
@SELECT ROUND((UNIX_TIMESTAMP()-(UNIX_TIMESTAMP(created_date)))/86400) AS age FROM table@

Esta version lo dedico a mi amigo Razvan Stroescu, bueno programador Java, a qual le vi una vez solviendome una duda en casi la misma manera. Todavia no soy tan bueno como tu, pero me gusta saber que soy en el camino corecto.

2. La segunda version es mas sencilla todavia. El language SQL tiene un monton de functiones predefindas, y gracias Manel Vaquero, mi colego de trabajo, ya conosco unas mas.

@SELECT TO_DAYS(CURRENT_DATE) – TO_DAYS(created_date)@

3. y una variante bonus:

@SELECT DATEDIFF(NOW(),created_date) AS days@

SQL es un superlanguage y espero que les gusta tal como a mi.

Cate zile de la data X – sintaxa de SQL

elzo valugi — Sun, 24 Jun 2007 21:06:02 +0000

Cum se calculeaza zilele de la o data pre-existenta dintr-un camp tip DATE sau DATETIME. In acest exemplu campul este created_date:

1. Prima versiune :
@SELECT ROUND((UNIX_TIMESTAMP()-(UNIX_TIMESTAMP(created_date)))/86400) AS age FROM table@

Versiunea asta mi’a fost inspirata. Prietenul meu Razvan Stroescu, programator Java, mi’a rezolvat odata o problema de genu asta exact in stilul asta. Inca nu am ajuns la nivelul lui, dar imi place sa stiu ca nu sunt pe drumul gresit.

2. A doua varianta este chiar mai simpla. SQL are o gramada de functii predefinite. Multumiri pentru sugestii lui Manel Vaquero, colegul meu actual de la care “fur” meserie

@SELECT TO_DAYS(CURRENT_DATE) – TO_DAYS(created_date)@

3. Si inca o varianta bonus

@SELECT DATEDIFF(NOW(),created_date) AS days@

SQL este un limbaj super tare, sper sa va placa cum imi place si mie.

Days until TODAY in SQL

elzo valugi — Sun, 24 Jun 2007 20:56:28 +0000

How to calculate the number of days till today starting from a field date or datetime – in this case created_date.table :

1. My first version:
@SELECT ROUND((UNIX_TIMESTAMP()-(UNIX_TIMESTAMP(created_date)))/86400) AS age FROM table@

Actually I remember seeing one time my friend and Java programmer Razvan Stroescu doing it. I am glad I can do it now also.

2. The second way is even simpler. Thanks to Manel Vaquero, my colleague now.
@SELECT TO_DAYS(CURRENT_DATE) - TO_DAYS(created_date)@

3. Yet another way
@SELECT DATEDIFF(NOW(),created_date) AS days@
SQL is a very nice thing to learn. Enjoy it as I do