Powershell: Text Search In A Table Value

Shane O’Neill clarifies a misunderstanding in Powershell:

and you are running the following PowerShell command to check if the results contain a value…

1
2
3
$String = "abc"
$Array = @(Invoke-Sqlcmd -ServerInstance "SQLServer" -Database "Database" -Query "SELECT code FROM dbo.users")
$Array.Contains($string)

It will return FALSE.

Now we know that the FALSE is false because we know that the string is in there!
This code is proven to work with arrays as stated here by the “Hey, Scripting Guy!”s so this was getting filed under “WTF PowerShell”

It’s a good post, so check it out and remember that DataRows aren’t strings.

Basic Powershell Regex

Adam Bertram shows how to use regular expressions for pattern matching in Powershell:

However, regex has traditionally been a topic that most IT pros shy away from when they first see how it works. Admittedly, regex does take a bit of getting used to, and you’re still probably going to have to do some Googling every time you need to use it. But learning how PowerShell integrates regex into its language is a skill that’s much easier learned and one that will come in handy often.

First of all, when someone says “working with regex,” that can mean a lot of things so let’s break it down a little bit. Regex is a method of string matching. Its sole purpose is to match and parse strings from within other strings. This can mean a lot of things and PowerShell allows you to do just about anything here, particularly as it has the full power of the .NET Framework. For our purposes, let’s investigate a few ways PowerShell allows you to match strings and how to parse strings with regex and PowerShell.

Read on for a couple sample scenarios.

Substrings: Powershell Versus T-SQL

Shane O’Neill contrasts the SUBSTRING function in T-SQL with Powershell’s Substring method:

The main difference that I can see when using SUBSTRING() in SQL Server versus in PowerShell is that SQL Server is very forgiving.

If you have a string that is 20 characters longs and you ask for everything from the 5th character to the 100th character, SQL Server is going to look at this, see that the string does not go to the 100th character, and just give you everything that it can.

It’s a small difference but an important one.

Automating Installation Of SQL Server

Nate Johnson has a script he uses to automate installation of SQL Server on a new server:

We can then use this file in the ConfigurationFile argument of setup.exe from the SQL Server install media.  To put a little more color on that: the .ini file is really just a collection of command-line arguments to setup.exe​; you could also list them all out in-line, but that would be tedious and silly.  Here’s a couple major selling points of creating your own config file:

  1. Slipstream updates (SP’s, CU’s), instead of having it go out to MSFT update servers (or *aghast* sticking with the original RTM bits, you heathen you!)

  2. Specify drive letters / default file locations: sure, this may be considered old-hat if you’re running super slick storage, but I still find it makes management a bit easier if I know where my MDFs, LDFs, TempDB, & backups will always be.

  3. Take advantage of 2016’s better TempDB setup options (# files, size & growth)

Read the whole thing.

Measure-Object Differences

Klaas Vandenberghe notes a discrepancy in how Measure-Object works, based on syntax:

So, is the -InputObject parameter broken? Not really, but we need to be aware of the logic behind it.
Maybe we are used to work with -ComputerName for a lot of cmdlets and functions, and we rely blindly upon the ability of the command to handle whatever collection we provide. We know this executes the action we chose, like Get-DbaSqlService or Get-DbaOperatingSystemor whatever, separately to every computer in the collection. The collection is ‘fold out’, ‘unpacked’, ‘split’.

-InputObject doesn’t do that! Is that wrong? Not necessarily, it may be a choice of design to have possibilities to enquire the properties of the collection itself and those of the ‘members’ or ‘children’. It’s just a surprise the behaviour differs from pipeline input to parameter input.

Something to keep in mind when writing Powershell scripts.

Powershell To Copy Reporting Services Subscriptions

Claudio Silva has a new contribution to the Reporting Services Powershell module:

If we take a look to the “New Subscription” form, we will discover about a dozen of fields that need to be configured. Doing this by hand can make you want to pull your hairs, also the probability of error is huge, even with copy & paste.
Who wants to do copy & paste of dozens of fields between reports? I know who doesn’t – me 🙂

Click through to learn more about Claudio’s cmdlets for getting, setting, and removing Reporting Services subscriptions.

ConvertTo-HTML Tips

Jeff Hicks shows off some of the niceties of Powershell’s ConvertTo-HTML cmdlet:

This is because Convertto-Html, like Export-CSV and Export-Clixml, take the entire object. This is not just the default result you see on the screen. Remember, everything will be treated as a string. In my example, if I want a similar HTML file, I will have to recreate the output with Select-Object. This might require piping the original result to Get-Member to discover the “real” property names.

It won’t output beautiful results, but with the appropriate CSS theming, you can generate good internal reports.

Installing DBATools Offline

Chrissy LeMaire shows how to save the dbatools module to install it offline:

There are essentially 3 ways to get the zip of our module

  1. From PowerShell Gallery using Save-Module

  2. From PowerShell Gallery by downloading from powershellgallery.com/api/v2/package/dbatools

  3. By downloading from dbatools.io/zip

Read on to see examples for each of the three methods.

Powershell Parameter VAlidation

Adam Bertram shows how to write safer code by validating parameters:

Simply adding [Parameter()] to the parameter block makes this function “advanced.” Once we have this in place, we can then add in some parameter validation code. In our case, we need to ensure that the file provided with FilePath actually exists before proceeding. To do this, we’ll use the ValidateScript attribute which allows us to run any code we want. As long as it returns $true, it will allow the function to run.

function Set-File {
param(
[Parameter()]
[ValidateScript({ Test-Path -Path $_ -PathType Leaf})]
[string]$FilePath
)
}

Notice that I used the pipeline variable $_ in this example. This represents whatever value the parameter is. If the user provides a file path that does not exist, they will be notified.

Read the whole thing.

Assigning Tags In Azure

Melissa Coates shows how to assign tags to resources in Azure using Powershell:

You can assign tags for resource groups, as well as individual resources which support Azure Resource Manager. The individual resources do not automatically inherit tags from the resource group parent. A maximum of 15 key/value pairs can be assigned (though you could store concatenated values or embedded JSON in a single tag value as a workaround). You may want to just assign tags at just the resource group level, and use custom queries to “inherit” at the resource level. Alternatively, you may want to assign tags to the individual resources directly particularly if you want to see them clearly on the standard “download usage” report of billing.

Since the key/value pairs are just free-form text, watch out for uniformity issues. To improve consistency, you can utilize policies to require tags and/or apply defaults if you’d like (for example, you might want to enforce a “Created By” tag). Tags can be set in the ARM template when you initially deploy a resource (which is best so that no billing occurs without proper tagging), or afterwards to existing resources via the portal, PowerShell, or CLI.

Melissa also shows how to query those tags using Powershell.

Categories

August 2017
MTWTFSS
« Jul  
 123456
78910111213
14151617181920
21222324252627
28293031