Tag Archive for SQL

Turning off the admin bar in WordPress 3.1

Work on WordPress 3.1 is in full swing at the moment though I initially though that they were taking a little break after 3.0. From what I can see, many refinements are being made to the multi-blog functionality and behind-the-scenes work is ongoing on the administration screens too.

Another under-the-bonnet change has been to make WordPress less tied to MySQL since the possibility of dropping in support for an alternative such as PostgreSQL is now a reality even if it isn’t part of the default package. For now, it looks as if this is going to be plugin territory rather than default multi-database support though that may become a sensible development in the light of Oracle’s acquisition of MySQL and its sabre rattling with regard to Java patents. So far, the change to WordPress has affected my use of its database engine to power an offline version of my online photo gallery but a quick spot of code editing sorted that issue.

One more obvious alteration is going to be the addition of a WordPress.com style administration bar to the top of all content and administration screens for a user who is logged into the system. It is going to be turned on by default but there will be the option of turning it off for those among who prefer things that way. All that will be needed for this is to add the following line near the top of wp-config.php:

define( “WP_SHOW_ADMIN_BAR”, false);

The chance to see new additions like those above and be ready for is my main reason for following WordPress development. It’s best to be ready than surprised though it has to be said that the blogging or CMS platform is a very polished one these days.

ERROR 22-322: Syntax error, expecting one of the following: a name, *.

This is one of the classic SAS errors that you can get from PROC SQL and it can be thrown by a number of things. Missing out a comma in a list of variables on a SELECT statement is one situation that will do it, as will having an extraneous one. As I discovered recently, an ill-defined SAS function nesting like LEFT(TRIM(PERIOD,BEST.)) will have the same effect; notice the missing PUT function in the example. The latter surprised me because I might have expected something more descriptive for this as would be the case in data step code. In the event, it took some looking before the problem hit me because it’s amazing how blind you can become to things that are staring you in the face. Familiarity really can make you pay less attention.

ERROR: Invalid value for width specified – width out of range

This could be the beginning of a series on error messages from PROC SQL that may appear unclear to a programmer more familiar with Data Step. The cause of my getting the message that heads this posting is that there was a numeric variable with a length less that the default of 8, not the best of situations. Sadly, the message doesn’t pin point the affected variable so it took some commenting out of pieces of code before I found the cause of the problem. That’s never to say that PROC SQL does not have debugging functionality in the form of FEEDBACK, NOEXEC, _METHOD and _TREE options on the PROC SQL line itself or the validation statement but neither of these seemed to help in this instance. Still, they’re worth keeping in mind for the future as is SAS Institute’s own page on SQL query debugging. Of course, now that I know what might be the cause, a simple PROC SQL report using the dictionary tables should help. The following code should do the needful:

proc sql;
select memname, name, type, length from dictionary.columns where libname=”DATA” and type=”num” and length ne 8;
quit;

Self-hosted web analytics tracking

It amazes me now to think how little tracking I used to do on my various web “experiments” only a few short years ago. However, there was a time when a mere web counter, perhaps displayed on web pages themselves, was enough to yield some level of satisfaction, or dissatisfaction in many a case. Things have come a long way since then and we now seem to have analytics packages all around us. In fact, we don’t even have to dig into our pockets to get our hands on the means to peruse this sort of information either.

At this point, I need to admit that I am known to make use of a few simultaneously but thoughts about reducing their number are coming to mind but there’ll be more on that later. Given that this site is hosted using WordPress software, it should come as no surprise that Automattic’s own plugin has been set into action to see how things are going. The main focus is on the total number of visits by day, week and month with a breakdown showing what pages are doing well as well as an indication of how people came to the site and what links they followed while there. Don’t go expecting details of your visitors like the software that they are using and the country where they are accessing the site with this minimalist option and satisfaction should head your way.

There is next to no way of discussing the subject of website analytics without mentioning Google’s comprehensive offering in the area. You have to admit that it’s comprehensive with perhaps the only bugbear being the lack of live tracking. That need has been addressed very effectively by Woopra, even if its WordPress plugin will not work with IE6. Otherwise, you need the desktop application (being written in Java, it’s a cross-platform affair and I have had it going in both Windows and Linux) but that works well too. Apart maybe from the lack of campaigns, Woopra supplies as good as all of the information that its main competitor provides. It certainly doe what I would need from it.

However, while they can be free as in beer, there are a some costs associated with using using external services like Google Analytics and Woopra. Their means of tracking your web pages for you is by executing a piece of JavaScript that needs to be added to every page. If you have everything set to use a common header or footer page, that shouldn’t be too laborious and there are plugins for publishing platforms like WordPress too. This way of working means that if anyone has JavaScript disabled or decides not to enable JavaScript for the requisite hosts while using the NoScript extension with Firefox, then your numbers are scuppered. Saying that, the same concerns probably any JavaScript code that you may want to execute but there’s another cost again: the calls to external websites can, even with the best attention in the world, slow down the loading of your own pages. Not only is additional JavaScript being run but there also is the latency caused by servers having to communicate across the web.

A self-hosted analytics package would avoid the latter and I found one recently through Lifehacker. Amazingly, it has been around for a while and I hadn’t known about it but I can’t say that I was actively looking for it either. Piwik, formerly known as PHPMyVisites, is the name of my discovery and it seems not too immature either. In fact, I’d venture that it does next to everything that Google Analytics does. While I’d prefer that it used PHP, JavaScript is its means of tracking web pages too. Nevertheless, page loading is still faster than with Google Analytics and/or Woopra and Firefox/NoScript users would only have to allow JavaScript for one site too. If you have had experience with installing PHP/MySQL powered publishing platforms like WordPress, Textpattern and such like, then putting Piwik in place is no ordeal. You may find yourself changing folder access but uploading of the required files, the specification of database credentials and adding an administration user is all fairly standard stuff. I have the thing tracking this edifice as well as my outdoor activities (hillwalking/cycling/photography) web presence and I cannot say that I have any complaints so we’ll see how it goes from here.

JavaScript: write it yourself or use a library?

I must admit that I have never been a great fan of JavaScript. For one thing, its need to interact with browser objects places you at the mercy of the purveyors of such pieces of software. Debugging is another fine art that can seem opaque to the the uninitiated since the amount and quality of the logging is determined an interpreter that isn’t provided by the language’s overseers. All in all, it seems to present a steep and obstacle-strewn learning curve to newcomers. As it happens, I have always found server side scripting languages like PHP and Perl to be more to my taste and I have no aversion at all to writing SQL.

In the late 1990′s when I was still using free web hosting, JavaScript probably was the best option for my then new online photo gallery. Whatever was the truth, it certainly was the way that I went. Learning Java or Flash might have been useful but I never managed to devote sufficient time to the task so JavaScript turned out to be the way forward until I got a taste of server side scripting. Moving to paid hosting allowed for that to develop and the JavaScript option took a back seat.

Based on my experience of the browser wars and working with JavaScript throughout their existence, I was more than a little surprised at the buzz surrounding AJAX. Ploughing part of the way through WROX’s Beginning AJAX did nothing to sell the technology to me; it came across as a very dry jargon-blighted read. Nevertheless, I do see the advantages of web applications being as responsive as their desktop equivalents but AJAX doesn’t always guarantee this; as someone that has seen such applications crawling on IE6, I can certainly vouch for this. In fact, I suspect that may be behind the appearance of technologies such as AIR and Silverlight so JavaScript may get usurped yet again, just like my move to a photo gallery powered on the server side.

Even with these concerns, using JavaScript to add a spot more interactivity is never a bad thing even if it can be overdone, hence the speed problems that I have witnessed. In fact, I have been known to use DOM scripting but I need to have the use in mind before I can experiment with a technology; I cannot do it the other way around. Nevertheless, I am keen to see what JavaScript libraries such as jQuery and Prototype might have to offer (both have been used in WordPress). I have happened on their respective websites so they might make good places to start and who knows where my curiosity might take me?

SAS9 SQL Constraints

With SAS 9, SAS Institute have introduced the sort sort of integrity constraints that have been bread and butter for relational database SQL programs but some SAS programmers may find them more restrictive than they might like. The main one that comes to my mind is the following:

proc sql noprint;
create table a as select a.*,b.var from a left join b on a.index=b.index;
quit;

Before SAS 9, that worked merrily with nary a comment but you now will see a warning like this:

WARNING: This CREATE TABLE statement recursively references the target table. A consequence of this is a possible data integrity problem.

In data step, the following still runs without a complaint:

data a;
merge a b(keep=index var);
by index;
run;

On the surface of it this does look inconsistent. From a database programmer’s point of view having to use different source and target datasets is no hardship but seems a little surplus to requirements for a SAS programmer trained to keep down the number of temporary datasets in an effort to reduce I/O and keep things tidy, an academic concept perhaps in these days of high processing power and large disks. Adding UNDO_POLICY=NONE to the PROC SQL line does make everything consistent again but I see this as being anathema to a database programming type. I do admit to indulging in the override for personal quick and dirty purposes but abiding by the constraint is how I do things for formal purposes like inclusion in an application.

  • As is commonly the case with places like these, all the views that you find expressed on here in postings and articles are mine alone and not those of any organisation with which I have any association, through work or otherwise. With regards to any comments left on the site, I reserve the right to reject any that are inappropriate. Otherwise, whatever is said is the sole responsibility of whoever is leaving the comment.

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