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Take Part in or Host an Hour of Code This Week!

This week, December 8-14, 2014 is Computer Science Education Week! Since its inception in 2013, the Hour of Code movement has been gaining steam. During just the CSE Week last year, 15 million students took part.

There have never been more free resources for learning the basics of programming. Code.org, the founders of the Hour of Code, has lots of ways that someone can take part in, or even host an Hour of Code this week.

One resource that I don’t see mentioned on any of these pages, though it is quite good for a free resource, is Codecademy. JavaScript, Ruby, Python, and PHP are just some of the skills that you can begin learning about there.

If you’ve never programmed before, but you’ve wanted to learn, there’s no time like the present to get started!

Code School will be Having a Black Friday Special!

I have found Code School to be a great resource both for those just learning to code as well as those who are experienced coders, but want to learn a new programming language. It has multiple paths: Ruby (including Ruby on Rails), JavaScript (includes jQuery and CoffeeScript), HTML/CSS, iOS, Git, and an Electives path for miscellaneous technologies such as R and Chrome DevTools.

The normal price for a subscription at Code School is $29 per month, or $290 per year. However, it appears that they intend to run a Black Friday special for yearly subscriptions. The price will be revealed this Friday. If you don’t already have a subscription, or your subscription is about to run out, this could be a good time to sign up!

Unfortunately, Code School is still lacking Python, though you can learn it at Codecademy (which is free).

Creating Compressed Files for Each Folder

I had quite a few folders that I wished to compress into ZIP files, all of which happened to exist in a single folder. In Windows, you can certainly compress multiple folders by selecting them all and then right-clicking and selecting “Send To” –> “Compressed (zipped) Folder”. However, this will put all folders into a single zipped file. What if I wanted each folder to have its own zipped file?

Using 7-Zip, I was easily able to do this.

Once 7-Zip is installed, open a Command Prompt and change to the folder in which all your to-be-compressed subfolders reside. The command below will create ZIP files, also in the main folder, from all those subfolders. The assumption here is that 7-Zip is installed in “C:\Program Files\7-Zip”; if it is elswhere change this attribute accordingly.

FOR /F "usebackq delims=?" %i IN (`DIR /B /A:D`) DO "C:\Program Files\7-Zip\7z.exe" a "%i.zip" "%i"

For some other options you can use, this post was of great help.

Converting WebEx Video Files to MP4 Format

I recently used WebEx to record a video conference that I intend to post on YouTube at some point in the future, though getting the video file into a format that is acceptable has not been as straightforward as it should be.

When using WebEx to record video, you can either choose to record on the server or on your computer. I chose to record on the server, then download the file to a PC for format conversion. First of all, in order to play or convert the file, you will need the WebEx Network Recording Player. This is because WebEx files are stored in a proprietary format with the “.arf” extension. I found that downloading the player through the link on the website did not give me the most recent version of the player (, as of 10-8-2014), but a version that was a couple of years old. The older version could not play the video I had just recorded, so I had to look for the current version, which I was able to find using these instructions.

Once you have the newest player installed, load the “arf” file and stop it from playing by clicking the stop button. Now you’re ready to convert the file. Use File –> Convert Format –> (whatever format you choose: WMV – Windows Media, SWF – Adobe Flash, or MP4). I chose MP4. This conversion process may take awhile, possible as long as the video is. Here’s where I ran into trouble. I selected the filename which I wanted the destination file to have, and it created that file (empty, at this point) along with a few other temporary files that were used for the conversion process. When the conversion process was complete, the MP4 file was deleted but a file with a seemingly random filename and a “.tmp” extension was left. Due to a bug in the conversion process, no MP4 file was present at this time.

I decided to see if the “tmp” file held the converted video, and fortunately it did. I changed the extension to mp4, and was able to open the file in Windows Media Player. Now, after some editing, I will be able to upload it to YouTube. Success!

The New City of Houston City-Wide Fee Schedule has been Published!

Back in 2013, I was on the winning team for the City of Houston’s Open Innovation Hackathon, and we produced a replacement for the previous fee schedule. The new fee schedule is now on the public City of Houston website!

SQL Server Script to Check for Blocking Queries

Even though SQL Server 2000 is no longer officially supported by Microsoft, quite a few SQL 2K databases still exist in production environments. One that had been giving me trouble for a couple of days was intermittently causing a web app to fail, and the error message indicated that the failure due to either a SQL timeout or an unresponsive server. This problem was not constant, but happened every few minutes.

Several other apps that accessed the same database as the one that was only working some of the time. Each app had its own set of tables, so I figured there must be exclusive locks being set on the tables that the problem app used. To determine the cause of this problem, I had to find out what process was locking the table.

This being SQL 2000, I could not use this script, which works on SQL 2008:

USE master
db.name DBName,
OBJECT_NAME(p.OBJECT_ID) BlockedObjectName,
h1.TEXT AS RequestingText,
h2.TEXT AS BlockingTest,
FROM sys.dm_tran_locks AS tl
INNER JOIN sys.databases db ON db.database_id = tl.resource_database_id
INNER JOIN sys.dm_os_waiting_tasks AS wt ON tl.lock_owner_address = wt.resource_address
INNER JOIN sys.partitions AS p ON p.hobt_id = tl.resource_associated_entity_id
INNER JOIN sys.dm_exec_connections ec1 ON ec1.session_id = tl.request_session_id
INNER JOIN sys.dm_exec_connections ec2 ON ec2.session_id = wt.blocking_session_id
CROSS APPLY sys.dm_exec_sql_text(ec1.most_recent_sql_handle) AS h1
CROSS APPLY sys.dm_exec_sql_text(ec2.most_recent_sql_handle) AS h2

For SQL 2000, try this one:

USE master
EXEC master.dbo.sp_lock
EXEC master.dbo.sp_who2
SELECT req_spid AS 'spid', 
DB_NAME(rsc_dbid) AS 'Database', 
OBJECT_NAME(rsc_objid) AS 'Name', 
rsc_indid AS 'Index', 
rsc_text AS 'Description', 
ResourceType = CASE WHEN rsc_type = 1 THEN 'NULL Resource'
	WHEN rsc_type = 2 THEN 'Database' 
	WHEN rsc_type = 3 THEN 'File'
	WHEN rsc_type = 4 THEN 'Index' 
	WHEN rsc_type = 5 THEN 'Table' 
	WHEN rsc_type = 6 THEN 'Page'
	WHEN rsc_type = 7 THEN 'Key'
	WHEN rsc_type = 8 THEN 'Extent'
	WHEN rsc_type = 9 THEN 'RID (Row ID)'
	WHEN rsc_type = 10 THEN 'Application'
	ELSE 'Unknown'
Status = CASE WHEN req_status = 1 THEN 'Granted' 
	WHEN req_status = 2 THEN 'Converting' 
	WHEN req_status = 3 THEN 'Waiting' 
	ELSE 'Unknown' 
OwnerType = CASE WHEN req_ownertype = 1 THEN 'Transaction' 
	WHEN req_ownertype = 2 THEN 'Cursor' 
	WHEN req_ownertype = 3 THEN 'Session' 
	WHEN req_ownertype = 4 THEN 'ExSession' 
	ELSE 'Unknown' 
LockRequestMode = CASE WHEN req_mode = 0 THEN 'No access ' 
	WHEN req_mode = 1 THEN 'Sch-S (Schema stability)' 
	WHEN req_mode = 2 THEN 'Sch-M (Schema modification)'
	WHEN req_mode = 3 THEN 'S (Shared)' 
	WHEN req_mode = 4 THEN 'U (Update)' 
	WHEN req_mode = 5 THEN 'X (Exclusive)' 
	WHEN req_mode = 6 THEN 'IS (Intent Shared)' 
	WHEN req_mode = 7 THEN 'IU (Intent Update)' 
	WHEN req_mode = 8 THEN 'IX (Intent Exclusive)' 
	WHEN req_mode = 9 THEN 'SIU (Shared Intent Update)'
	WHEN req_mode = 10 THEN 'SIX (Shared Intent Exclusive)'
	WHEN req_mode = 11 THEN 'UIX (Update Intent Exclusive)' 
	WHEN req_mode = 12 THEN 'BU. (Bulk operations)' 
	WHEN req_mode = 13 THEN 'RangeS_S' 
	WHEN req_mode = 14 THEN 'RangeS_U' 
	WHEN req_mode = 15 THEN 'RangeI_N' 
	WHEN req_mode = 16 THEN 'RangeI_S' 
	WHEN req_mode = 17 THEN 'RangeI_U' 
	WHEN req_mode = 18 THEN 'RangeI_X' 
	WHEN req_mode = 19 THEN 'RangeX_S' 
	WHEN req_mode = 20 THEN 'RangeX_U' 
	WHEN req_mode = 21 THEN 'RangeX_X' 
	ELSE 'Unknown' 
FROM master.dbo.syslockinfo 
SELECT * FROM master.dbo.sysprocesses

This query generates several tables, and the last table is most helpful. The “blocked” column will show how many exclusive locks are being held by the process denoted by the number in the “spid” column.

If you have DBA access, you can run “DBCC INPUTBUFFER(spid)”, substituting the spid number found above, and the text of the troublemaking query will be returned.

Converting a SQL DATETIME to a JavaScript Date

It should come as no surprise to anyone who has developed for multiple browsers that each one has its own quirks when it comes to enforcing standards, whether they be CSS, HTML5, or even JavaScript. I have been working on some JavaScript that will take a date (in the DATETIME format) from SQL Server and create a new JavaScript Date object using this date. In doing most web development, I have been using Chrome to test the pages first because I find Chrome’s developer tools much better than those with Internet Explorer, even though the site will eventually have to be compatible with IE 8+.

Apparently, when taking a SQL DATETIME (which is in the format “yyyy-mm-dd hh:mm:ss.ms”) string and creating a new JS Date, Chrome will take it directly, but IE is more strict. IE enforces the JavaScript standard, and simply doesn’t recognize the DATETIME format as being a valid date. The way I solved this was to parse the DATETIME string by splitting it into arrays and instantiating the JS Date object by using the “new Date(year, month, day, hour, minute, second, millisecond)” syntax.

Below is a function that will take a string in the SQL DATETIME format and will return a JS Date object:

function sqlToJsDate(sqlDate){
    //sqlDate in SQL DATETIME format ("yyyy-mm-dd hh:mm:ss.ms")
    var sqlDateArr1 = sqlDate.split("-");
    //format of sqlDateArr1[] = ['yyyy','mm','dd hh:mm:ms']
    var sYear = sqlDateArr1[0];
    var sMonth = (Number(sqlDateArr1[1]) - 1).toString();
    var sqlDateArr2 = sqlDateArr1[2].split(" ");
    //format of sqlDateArr2[] = ['dd', 'hh:mm:ss.ms']
    var sDay = sqlDateArr2[0];
    var sqlDateArr3 = sqlDateArr2[1].split(":");
    //format of sqlDateArr3[] = ['hh','mm','ss.ms']
    var sHour = sqlDateArr3[0];
    var sMinute = sqlDateArr3[1];
    var sqlDateArr4 = sqlDateArr3[2].split(".");
    //format of sqlDateArr4[] = ['ss','ms']
    var sSecond = sqlDateArr4[0];
    var sMillisecond = sqlDateArr4[1];
    return new Date(sYear,sMonth,sDay,sHour,sMinute,sSecond,sMillisecond);