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Category: Short and Sweet

Removing Microsoft’s News In The Taskbar

So in a “not shit crap again” post – MSFT releases a “News” update to take up space on your taskbar and just allow Microsoft to serve you more ads.

The boiling of the frog of the modern treatment of privacy is so annoying, so here’s the registry path to disable it.

Cool that you get to open the registry instead of just get presented a “Would you like a new informative tool by Microsoft?” It’s almost like they know that NOBODY wants this.

Remember – dont just randomly run registry files – they are plain text documents interpreted in a special way – so crack them open and make sure you feel comfortable running them.

You can review/download the data here:

How do companies handle blue green deployments with their SQL Server Database?

An interesting discussion/question in the SQL Community Slack today arose around how to implement blue/green deploys.

If you’re not familiar – blue/green refers to a deployment strategy with at least two hosts of your services, where you host in the green, deploy to the blue, and slowly drain the green to the blue until it becomes the green.

This has consequences in terms of keeping the lights on for both services, potentially rolling back the traffic to the green node (if the blue deployment fails some tests) and identifying things like dead code/data paths.

I was pondering how to answer the question in anything but the most generic way when this youtube video by Kevin Feasel was posted and it’s such a great resource I’m reposting it.

Thanks @reid and Kevin!

Fixing Unicode Conversion Issues in XML documents, TRY_CONVERT returns question mark instead of NULL

An interesting question asked by @danthesqlman in #sqlhelp (sqlcommunity.slack.com)

Having issues with Unicode in my XML, tried using a try_convert(varchar,fieldname) but not returning NULL.
Set it to have a test on my box, and weird results.
declare @n nvarchar(10) = N’ניקודות‎’
select try_convert(varchar(10),@n)
This doesn’t return NULL, but ?????????
I’m curious what would I be doing wrong, or how can i locate unicode within XML easily

And then when people suggested individual character shredding –

XML documents in a table over 200k rows, 2mb xml each, could take hours to parse 1 character at a time

There were a few suggestions, (my initial crap one was just dumping it to C#), but after a few jokes back and forth about how SQL Server was just returning normal question marks for TRY_CONVERT and how silly that was the idea came up… why not just:

  1. Replace all question marks with something unique? (I suggested a GUID)
  2. Run the conversion and then do a reverse replace, updating the data in place.
  3. Profit!

For a simple code example…

DECLARE @magic_value UNIQUEIDENTIFIER = NEWID()
SELECT
TRY_CONVERT
(
VARCHAR(100),
REPLACE(tar.name,'?',@magic_value)
)
FROM target_table AS tar

Any new question marks that exist in the output would be characters that failed the conversion process.

The test ran in ten minutes instead of a few hours… great!

Also a fun followup on weird SQL Server homoglyph conversion issues in general – https://bertwagner.com/posts/how-unicode-homoglyphs-can-thwart-your-database-security/

Disable powershell update nag in one line

[System.Environment]::SetEnvironmentVariable("POWERSHELL_UPDATECHECK",0,[System.EnvironmentVariableTarget]::User)

To be clear – I think you should be updating your PowerShell regularly, however the HUGE WHITE BLOCK ACROSS MY ENTIRE SCREEN EVERY TIME I LAUNCH VISUAL STUDIO CODE ISN’T GREAT.

Hated that caps? Yeah, that’s basically my eyes every time I see this nag window inverting the colors across my ennntiiirrreee screen.

I checked the PS repo and some one liners posted didnt work (and used SetEnvironmentVariableTarget which was not a method I had?), so I wanted to make this easy in case you are getting frustrated with the PowerShell update version check message and you want it to go away and didnt want to crack open the environment variables.

Now go update your PowerShell 🙂

Useful Django Bits

I have been busy working on some other non-SQL related side projects recently, and I wanted to note some of the pieces of code I have been appreciating recently.

https://github.com/PaesslerAG/django-currentuser is a simple plugin that allows you to reference your current user context in your models various functions. This greatly simplified some user management functions within my codebase, as I could express it all in the model.

https://www.django-rest-framework.org/ is a powerful framework on top of Django that allows you to build a straightforward rest framework. Django doesn’t have object based permissions and I have been building out the next version of my codebase with it, its definitely a lot more pluggable than anything I designed.

https://pythoncircle.com/post/439/server-access-logging-in-django-using-middleware/ an easy way to track user access – one migration adds a log to your table, and you get whatever you want out of each request flow. Be careful that you follow your GDPR/CCPA guidelines!

https://github.com/pennersr/django-allauth is something I have been investigating but it seems a bit much for my goals, I will come back and update more about this soon.

Grouping groups of strings within strings in TSQL.

So a friend of mine had a query puzzle – he needed to print some W2 forms but the forms themselves only allows up to 4 groups of a value to be placed in a box or else they’d need to issue two forms.

The pickle is that the source data is freeform csv text, so what can we do on the database side?

I reached for my handy CROSS APPLY, a numbers table, windowing functions and a little modulo arithmetic – its not so bad to return a subgroup within a group in SQL as long as you are willing to lay out additional columns to count your grouping.

Dynamic UNPIVOT Reporting on Cardinality.

Today I was diving into some extremely wide tables, I wanted to take a quick look at things like “How many unique values does this table have in every column?”.

This can be super useful if you have a spreadsheet of results or a schema without effective normalization and you want to determine which rows are the “most unique” – or have high cardinality.

The Github gist is embedded at the bottom of the page, but I will run you through the code in case you want an explanation of how it works

The procedure takes a schema and a table/view name and combines them – I could ask the user to do this for me, but there’s parts where its useful to break them up and I dont want to mess with split logic :p

The procedure is defined as a temporary stored procedure as I didnt want to leave a trace when I disconnect.

I then define the dynamic UNPIVOT statement, which we will feed our dynamic column listing from.

Gather our columns (twice) – once for the COUNT(DISTINCT), and once for the use in the columns we want to UNPIVOT.

Here’s an example of running it against a tsqlt testresult table:


As we can see, the tsqlt testresult table has one class, two messages and results, and unique everything else (so that’s where I will focus.)

I also utilize a @magic_value variable in the code (not shown) which I use to deal with the fact that a NULL value in an UNPIVOT statement wont count as an occurrence. I want to disambiguate from NULL and any particular value that might occur, so using something like -1 or some string NULL would be inappropriate.

That’s it for today!

Grab the full code below –

Update: T-SQL Notebooks in Azure Data Studio

It’s only been ten days since my first post about ADS Notebooks, and the team has already pushed out some super useful updates.

Now launching an Azure Data Studio Notebook now is almost instantaneous. You are not prompted to install the other kernels unless you select them.

When reopening a file, you no longer are prompted to re-install a kernel and attempt configuration.

Displays Azure Data Studio Notebooks behavior when reopening a notebook

Big thanks ADS team, Notebooks look to be shaping up to be a super cool tool!

Removing non-numeric characters from a SQL Server field without UDFs or Regex

A great question came up in the SQL Community Slack today:

I saw this as a great modification on my earlier post, and wanted to show another way to implement the same solution.

Walking through the steps:

First, use sys.objects as our example “target” and assume the string has less than 2024 characters (spt..numbers isnt really reliable past that point.)

We substring out each character and compare it to the list of items we accept, and then collapse the list back in on itself.

At the end, I pull out sys.objects for comparison so you can see what sort or results you would get. Enjoy!