Categories
PowerShell Quick Tips Regex

Using Case-Sensitive Regular expressions in PowerShell – Tips

Say you want to find functions that uses parameters named like:
-AsString, -AsHashTable, or -AsByteStream

Using Find-Member makes it easy.

> Find-Member -Name 'As*'

That’s close, but I want it to start with a capital letter, to skip matches like:
Assembly or Asin

Converting Like to a Regex

The -like pattern As* is the same as the regex ^As
To start with a capital letter you could use: ^As[A-Z]

Disabling Case-Sensitive matches

Because PowerShell defaults to case-insensitive matches
You need to remove the i insensitive flag using the syntax (?-i)

Solution

> Find-Member -Name '(?-i)^As[A-Z]' -RegularExpression

The final pattern is (?-i)^As[A-Z]
Making it case-sensitive narrowed down the matches from 113 to 43 !

See More

Categories
Power BI Quick Tips

Tip: Controlling a Column’s “Summarize By” Type in Power BI

The Model view allows you to set a global default “Summarize By” type for every column.
You still have the ability to override the aggregation type per-visual in Report view


Categories
Power BI Power Query Reference What's New

Searching Constants Defined in Power Query

Searching Power Query Language Functions and Constants

Categories
Power BI What's New

Power BI Updates – 2020-08-17

Guy In a Cube: July roundup

He covers and links these topics:

PBI Patch Notes Summary

Power BI Desktop July 2020 feature summary

External tools

Tabular Editor

https://tabulareditor.com/

Dax Studio

https://daxstudio.org/

ALM Toolkit

ALM Toolkit

sqlbi.com/alm-toolkit

Categories
Power BI Power Query Reference

Resources to learn Power Query

Tutorials

Ben Gribaudo dives into Power Query topic by topic

Part 1: Introduction to let expressions
Part 3: Using and writing Functions
Part 8: Time: date, time, datetime, datetimezone and duration
Part 11-13: Tables
Part 15: Error handling
Part 16: Power Query primative types
Part 17: Facets
Part 18: Custom types


Chris Webb’s blog: Crossjoin.co.uk
Another high quality resource.
How to use Web API’s through Web.Content‘s Query and RelativePath parameters
He knew how to fix Web.Contents() refresh errors all the way back in 2016!

Documentation

Tools

VS Code extension: Power Query

If you use the advanced editor check this out.
It supports autocomplete Tool tips display optional parameters.

VS Code extension: Power Query uses PowerQuery-Parser and PowerQuery-Formatter

Query Diagnostics

Query Diagnostics in Power BI

Tips

You can copy -> paste multiple queries into a new Power BI Report (notice it included a required referenced query ListAsText even though I didn’t select it.
You can copy -> paste multiple queries into at text editor

Categories
Power BI Power Query

Importing text files in Power BI

What do you do when text files are not formatted as .csv or .json ? If they repeat a pattern, you can automate it.

( You can download the final .PBIX report here )

This file always uses:

  • 3 values for for each “table” row
  • One line per value – which becomes our “columns”
  • every “column” line has a : in it. If you skip all lines without a : it filters all unwanted lines
Title
---------------------
DeviceID: One
Info1: One:Info1
Info2: One:Info2

---------------------

DeviceID: Two
Info1: Two: Info1
Info2: Two: Info2

---------------------

DeviceID: DeviceID
Info1: Three: Info1
Info2: Three: Info2

First take a look at the final function. Then I’ll explain how it works.

The main query calls a custom function

ConvertTableFromTextLines( "c:\data\sample.txt", ":", 3 )

All the work is one here

let  ConvertTableFromText = (filepath as text, splitCharacter as text, linesPerRecord as number, optional encoding as nullable number) as table =>
    let
        TextLines = Lines.FromBinary(
            File.Contents( filepath, null ),
            null,
            null,
            encoding ?? TextEncoding.Utf8
        ),
        TextLineTable = Table.FromColumns(
            { TextLines }, {"Line"}
        ),

        Pairs = Table.SelectRows(
            TextLineTable,
            each Text.Contains( [Line], splitCharacter )
        ),

        SingleRecordAsCols = Table.SplitColumn(
            Pairs,
            "Line",
            Splitter.SplitTextByEachDelimiter(
                { splitCharacter }, QuoteStyle.Csv, false
            ),
            {"Name", "Value"}
        ),

        TotalLines = Table.RowCount( SingleRecordAsCols ) ,
        NumberOfGroups = TotalLines / linesPerRecord,

        ListOfRecords = List.Generate(
            () => 0,
            each _ < NumberOfGroups,
            each _ + 1,
            each (
                Record.FromTable(
                    Table.Range(
                        SingleRecordAsCols,
                        _ * linesPerRecord,
                        linesPerRecord
                    )
                )
            )
        ),
        t = Table.FromList(
            ListOfRecords, Splitter.SplitByNothing(), null, null, ExtraValues.Error
        ),

        columnNameList = Record.FieldNames( ListOfRecords{0} ),

        TableOfRecords = Table.ExpandRecordColumn(
            t, "Column1", columnNameList, columnNameList

        )
    in
        TableOfRecords
in
    ConvertTableFromText

First we load the text file as a list. File.Contents( filepath ) reads all file types. Lines.FromBinary( Contents ) converts it into text. Depending on how the file was saved, you may need to set the encoding

Don’t worry if encoding sounds scary. If text loads with the wrong characters, try the other one. Two good ones to try first are:

TextEncoding.WindowsPower BI defaults to this for windows files
TextEncoding.Utf8Anything on the internet uses UTF8 by default.
Tip: If a file truly is ASCII then UTF8 will work

Next remove any lines that are missing :

Then split each line into two columns:
Transform Column -> Text -> Split -> By Delimiter

I started with these options

I renamed them to Name and Value because they will be converted into records.

To convert multiple lines into a single recordI used List.Generate. You can think of it like a for loop

There are

  • 3 lines per record
  • 9 total lines = the number of lines in the file
  • 3 total groups = 9 total lines / 3 lines per record

We need to loop 3 times. I’ll recreate a loop like this, converted to Power Query

for( $i = 0 ; $i < NumberOfGroups; $i += 1){
    CreateRecord()
}

List.Generate() has 4 arguments. Each one is a function. It uses:

  • initialize sets your starting condition. ( set i to 0 )
  • condition tests if we’ve reached the total number of groups
  • next changes the value of i. We want to add 1
    optional selector function creates the value every loop. This calls CreateRecord() once for every loop
    ListOfRecords = List.Generate(
        () => 0,
        each _ < NumberOfGroups,
        each _ + 1,
        each (
            Record.FromTable( 
                Table.Range(
                    SingleRecordAsCols,
                    _ * linesPerRecord,
                    linesPerRecord
                )
            )
        )
    ),

The next function first grabs rows from the table SingleRecordAsCols. It converts those into a single record

Every loop 3 is added to the offset.

i valueoffsetcount
00 * 3 = 03
11 * 3 = 33
22 * 3 = 63

You end up with a list of records

Choose convert to table

Finally expand records to columns

The final result:

Categories
Reference

The many names of Microsoft

Current namePrevious names
Power AutomateFlow
Power QueryM
PowershellPowershell Core (this is opensource and uses .net core)
Windows PowershellPowershell (this uses .net )
Azure Data StudioSQL Operations Studio