Add column that does not refresh in powerquery / excel - excel

I try to combine a power query generated view with a column for user input during a review session.
I would like to prevent this column from changing upon data refresh.
A | B
--------------
Stats | Review
Long | good
Short | bad
A can update. B is unknown at query time and therefore created with empty values. It is populated by the user. I want to update A, but don't remove the values in B.
I tried to add column B in excel instead of power query, after generating the query to an Excel table. It kind of works as the values stay in the column. However, the order is messed up when I refresh.
Ultimately I think this might be possible with power query when generating the table.
Can this command be modified to get the desired behavior on the column?
Table.AddColumn(#"A", "B", each null)
Sorry for the bad example, its kind of hard to show proper excel/powerquery 'code'.

Related

PowerBI: Comparing a filterd table against a variable string is returning an empty table

Please see the code below for a Power BI table in DAX:
TABLE1 =
VAR ParticipantOneParticipantId =
SELECTEDVALUE(
ParticipantOneDetails[ParticipantId]
)
RETURN
FILTER(
ParticipantOneMeetings,
ParticipantOneMeetings[ParticipantId] = ParticipantOneParticipantId
)
I am fetching a value for ParticipantId from a sliced table called ParticipantOneDetails and setting ParticipantOneParticipantId to it.
In the next step I am trying to filter the table ParticipantOneMeetings based on its column ParticipantId comparing it against ParticipantOneParticipantId.
The problem is that the resulting table is coming out empty even though I know that ParticipantOneParticipantId must have a value and the ParticipantOneMeetings table also has values. I verified by comparing against a hard-coded string.
Can you please point out what I am doing wrong? Is comparing this way not legal?
The problem lies in the process you are trying. A calculated/custom tables and columns are static. They always refresh when the data set is refreshed. They do not interact dynamically with the slicer value. So it is impossible to get data from a slicer dynamically for a Custom Table generation.
Now, your requirement of creating a new table based on slicer value is not completely clear to me. As what you are trying, is a simple filtered output of your table "ParticipantOneMeetings" after applying the Slicer. If you have relation between your 2 tables using column "ParticipantId", change in Slicer will automatically filter out values in ParticipantOneMeetings table. Why you wants to hold this same filtered values in a new Custom table is really a mater here to know for finding appropriate solution for you.
Turns out I needed to add the following measure to the table output:
MeetingsAttendedByBothParticipants =
countrows(
INTERSECT(
VALUES(ParticipantOneMeetings[Name]),
VALUES(ParticipantTwoMeetings[Name])
)
)
The above provides an intersection on output of two sliced meeting tables. This results in a list of meetings that both persons attend.

Power Query: how can I make power query tolerate columns with the same name?

I have a table with several column having the same name.
This columns is updated and provided regularly to power bi.
The columns has several columns with the same name such as "Result", "Result" and do so on...
However, Power BI adds each time in an automated way a number after my columns.
When I try to "force" power bi not to have a number, I get the following message
"The name "Result" is already used for a column..."
How could I change this?
The only way would be for the people using my file to extract the data and correct the name manually in excel...which is not great
You cannot edit this behavior, PowerBI needs an unique identifier to reference the data, therefore the column name must be unique within a table (the complete identifier is given by table + column), otherwise the tool won't be able to reference the data.
This rule usually applies to any tool that manages data and sometimes to the data themselves (that's up to the format though). How can the tool get data from "Result" if more than one column has this identifier? which is the right one? The tool does not know and based on the context can give you an error or will fix this issue itself by making the names unique.
Note that also excel will append numbers to the columns (with the same name names) if you put the data in a proper table (insert-> table), in fact, an excel sheet can be considered unstructured free data, meanwhile, an excel table will enforce the data structure.
Most tools (like PowerBI) will also enforce data types.

Default date aggregation for Excel

What is the default behavior of adding a date, time, or datetime into an Excel pivot row/column? I have seen it sometimes add it as the "raw value", sometimes it will add it as a Year > Query > Value, and other times (?) perhaps in between. For example:
When does Excel add it without aggregating it, and when does Excel aggregate it? Does it have to do with value cardinality, date range, or something else?
First, every entry in the column has to be a date/time or you won't be able to group them. In that case, obviously, the default would be not grouped.
Assuming everything is groupable, the default is no grouping. Each date will show individually.
The exception is if a pivot cache already exists. In that case it will group based on what the pivot cache says - the last way that field was grouped. This happens when you have more than one pivot table on the same data. The first pivot table creates the cache and all subsequent pivot tables use that existing cache.
In a new workbook (2010), I add a date field to the Row Labels and they are initially ungrouped by default.
I group them by month
Now I go back to the original data and make a new pivot table. I add the date field to the Column Labels.
Because it uses the same cache, it automatically has them grouped the same way. Finally, I go back to the source data and replace one of the dates with a string. If I create another pivot table, it will look like the others. But when I refresh it ungroups them because I have a non-date in there.
And if I try to Group now, it says "Cannot group that selection"
That's why it works the way it does - shared pivot cache. There are ways you can give each pivot table it's own cache but that uses more memory. However, if you want to group the same data differently, that's what you have to do.

Excel Power Query - Incremental Load from Query and adding date

I am trying to do something quite simple which I am failing to understand.
Take the output from a query, date time stamp and write it into a Excel table.
Iterate the logic again and you get the same output but the generated date time has progressed in time.
Query 1 -- From SQL which yields 2 columns category, count.
I am taking this and adding a generated date to it using DateTime.LocalNow().
Query 2 -- Target table
How can i construct a query which adds to an existing table and doesnt require me to load the result into a new table.
I have seen this blog.oraylis.de and i cant make it work since the DateTime.LocalNow() call runs for source and target and i end up with the same datetime throughout the query.
I think i am missing something obvious.
EDIT:-
= Table.Combine({SOURCE_DATA, TARGET_DATA})
This loads into a 3rd new table and doesnt take into account that 3rd table when loading - so you just end up with a new version of just the first two tables with new timestamp
These steps should work
create a query Q1 based on the SQL Statement, add your timestamp using DateTime.LocalNow() and load this into an Excel table (execute the query)
create a new query Q2 based on this Excel new table (just like that, no transforms)
Modify the first query Q1 by adding the Table.Combine with Q2 as the last step.
So, in other words, Q2 loads the existing data from the Excel table into which Q1 writes. The Excel table is always written completely but since the existing data is preserved you will get the result of new data being loaded to the table. Hope this helps.
Good luck, Hilmar

Creating "Categories" to show on a PivotTable

I have a student database, and I'm trying to show different metrics based on a student's score range in a PivotTable. Specifically (this is a simplified example, so don't worry about the content) I want to show this in my pivot:
StudentGPACat | Avg Post-Grad Salary
3-3.2 | 64,323
3.2-3.4 | 71,225
3.4-3.6 | etc
3.6-3.8 | etc
3.8-4.0 | etc
So I want the rows in my pivot table to show the range the student's average score falls in.
In order to generate that metric, right now, I did 2 things:
(1) Added a new column in my master table in PowerPivot called [avgGrade] that shows the value of the [TableAvgGrade] calculated field from the "Grades" table for each student (i.e., each row in the master table)
=CALCULATE([TableAvgGrade],
FILTER(Grades,Grades[studentID]=Master[studentID]))
(2) Created a new column [StudentGPACat] in PowerPivot and the formula goes:
=If([avgGrade]<3,"3",
If([avgGrade]<3.2,"3-3.2",
If([avgGrade]<3.4,"3.2-3.4",
If([avgGrade]<3.6,"3.4-3.6",
If([avgGrade]<3.8,"3.6-3.8","3.8-4.0")))))
This feels bulky and computationally expensive. Is there an easier way to create these ranges to use as rows in my PivotTable?
EDIT: made some edits to clarify my question
EDIT2: type
What you've done is the appropriate pattern for creating this sort of column. If you're concerned about the gnarly nested IF()s, you can replace with a SWITCH(), which is just syntactic sugar for nested IF()s, but what you've posted is all you need.
In a PivotTable (I don't know with PowerPivot), if you use a numeric value as a Row Label, you can Right click the field, choose Group, define the Starting at value, Ending at value and By step, and you will get an equivalent result quite easily.

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