Category: Powershell

Chrissy LeMaire shows off a very helpful command in dbatools:

Nearly every time I inherit a SQL Server environment, I’m only given a partial list of SQL Servers that exist on the network. It’s my usual routine to get permission to sniff the network then run about five different programs including Idera’s SQL Discovery and Microsoft’s SQL Server Assessment and Planning Toolkit.

I always thought it’d be cool to have one comprehensive PowerShell command that could do the work of all the above and was ecstatic to see NetSPI’s Scott Sutherland had written a few commands to do just that in his awesome PowerShell module PowerUpSQL.

When I saw Scott’s multi-pronged approach (including some UDP magic 🎩), I asked if he’d be interested in contributing to dbatools and he said yes! He submitted a gorgeous mock-up and I was so excited. Then came the PR, complete with great documentation and multithreading.

Click through for a lot more information on the command.

Shane O’Neill makes a discovery:

…if there is enough data to import this into the database & use T-SQL then you can bet that’s what I’m going to do! It’s what it was designed for, I’d find it easier, and it’s probably going to be faster after you hit a certain threshold.

However, if it’s small sets and the effort of importing the data is going to slow you down and break your flow…

Well, that doesn’t have to be the case anymore.

Read on to see joins in action.

Jana Sattainathan shows how to query a number of SQL Server instances in parallel using Powershell and collecting the PRINT outputs from each:

As an example, you may have a block of SQL that PRINTs out the current privileges in the databasethat can then be saved off and used as an independent script.

In my case today, I need to collect information on the Service Pack and Cumulative Updates that need to be installed/applied to 200+ SQL Server instances. MS provides the SQL script to identify the right SP and CU to install. Please make sure you download the zip file and unzip the long SQL. I need to run this SQL against the instances to get the info. However, the information returned is completely with PRINT statements!

Click through to see how Jana did it.

Shane O’Neill reminds us that reading is fundamental:

Glancing at the error message, the first things that stick out are the bits “{x,y}” so I change my regex to be anywhere from 1 to  digits "*\d{1,6}$"

Why are you glancing, read the error message!

That doesn’t work, so I again quickly scan the error message and see the bit “following nothing”

“Quickly scan”?! No, actually read the error message!!

This wasn’t a great error message, but at least it does make sense after the fact and it’s a case where actually reading the error message does clarify things.  The ones I really hate are “error 0x4849f8f8” types which aren’t even intended to make any sense to us.

Mark Broadbent has a quick Powershell script to read a selection from a giant text file:

I recently ran into this very same problem in which the bcp error message stated:

An error occurred while processing the file “D:\MyBigFeedFile.txt” on data row 123798766555678.

Given that the text file was far in excess of notepad++ limits (or even easy human interaction usability limits), I decided not to waste my time trying to find an editor that could cope and simply looked for a way to pull out a batch of lines from within the file programmatically to compare the good rows with the bad.

Click through for a precise and useful Powershell snippet.  The .NET file stream libraries are also good for this kind of thing.

Rob Sewell shows off how easily to splat Powershell parameters with Visual Studio Code:

Well you will know that when you call a PowerShell function you can use intellisense to get the parameters and sometimes the parameter values as well. This can leave you with a command that looks like this on the screen

1	Start-DbaMigration -Source $Source -Destination $Destination -BackupRestore -NetworkShare $Share -WithReplace -ReuseSourceFolderStructure -IncludeSupportDbs -NoAgentServer -NoAudits -NoResourceGovernor -NoSaRename -NoBackupDevices

It goes on and on and on and while it is easy to type once, it is not so easy to see which values have been chosen. It is also not so easy to change the values.

By Splatting the parameters it makes it much easier to read and also to alter.

To learn more about splatting, there’s a whole section in Powershell help on the topic.

Fred Weinmann gives us a reading list of Powershell built-in documentation:

Newcomers to PowerShell are often faced with a lot of things to learn, a lot of disorienting features and little in the way of obvious guidance. While there are quite a few good books out there by now, finding the right one is not always easy.

That said, PowerShell comes with a lot of built in documentation:

Get-Help about_*

Will list a whole lot of articles explaining many a concept, but finding just what you need – especially before you know all the right words to search for – is a lot harder.

There’s a lot to this and more seasoned developers can skip a lot of it, but if you’re just learning about Powershell, I think it’s a nice ordering of where to start learning.