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So i have been searching on this formula for a couple of days and can't figure it out
I am building a report to check if employees where present at certain events. However to calculate the totals for an event i need to know who was actually working at the date of that event.
I get this data from multiple tables
There is one table with info about the event containing a column with the actual date.
There is a second table with employees who are present at the event, linked with an event id to the actual event
Then i have a 3th table with employee information including in what team they are and their employment dates. Problem is that every time a change was made any parameter of their employment status there is a new entry with the same employee id but different dates (I have no control over this data source, this is an extract from the HR system)
eg.
| employee | StartDate | EndDate |
| Bob | 5-aug-2020 | 10-aug-2020 |
| Bob | 11-aug-2020 | 30-aug-2020 |
| Bob | 31-aug-2020 | 5-May-2021 |
| Geoff | 1-aug-2020 | 13-aug-2020 |
| Geoff | 14-aug-2020 | 30-aug-2020 |
| Geoff | 31-aug-2020 | 10-Apr-2021 |
| Geoff | 11-Apr-2020 | 1-Dec-9999 |
The problem is with this Table,
My report needs to show for each conference how many people where present and how many people are active in the team. I have a measure for my total present team members but when i try to build the measure for the total active team members on the given date the formula trows me an error that there is a many to one ration in this table.
A single value for column 'StartDate' in table 'EmployeeActive' cannot be determined. This can happen when a measure formula refers to a column that contains many values without specifying an aggregation such as min, max, count, or sum to get a single result.
the problem is that each period needs to be validated, i can not simply assume that the employees first employment date and last employment date in that period are the only dates, there could be a period in between where he/she was not active.
Hi,
That table is not proper. You should transform the table to show one data per cell for each employee. Delete the 1 Dec 9999 date. This M code does that
let
Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WcspPUtJRMjDVdSxN1zUyALINDWDsWB2YvKEhQt4Yi7wxkjzQLN/ESl0jQ7C8e2p+WhpIFEmFoTGyCTAVhia47ICpQLYF5MqCInRbQO4EiYJUKMXGAgA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [employee = _t, StartDate = _t, EndDate = _t]),
#"Changed Type" = Table.TransformColumnTypes(Source,{{"employee", type text}, {"StartDate", type date}, {"EndDate", type date}}),
#"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each if [EndDate]=null then DateTime.Date(DateTime.LocalNow()) else [EndDate]),
#"Removed Columns" = Table.RemoveColumns(#"Added Custom",{"EndDate"}),
#"Added Custom1" = Table.AddColumn(#"Removed Columns", "Date", each {Number.From([StartDate])..Number.From([Custom])}),
#"Expanded Date" = Table.ExpandListColumn(#"Added Custom1", "Date"),
#"Removed Columns1" = Table.RemoveColumns(#"Expanded Date",{"StartDate", "Custom"}),
#"Changed Type1" = Table.TransformColumnTypes(#"Removed Columns1",{{"Date", type date}})
in
#"Changed Type1"
The end result of the M code will be:
Hi, @tproost
Not very clear.
Please share a sample pbix file for further research.
You can also refer to these related documents to check the error message.
https://www.sqlbi.com/articles/dax-error-messages-in-power-bi/
Error-This-can-happen-when-a-measure-formula-refers-to-a-column
a-single-calue-for-column-cannot-be-determined
Best Regards,
Community Support Team _ Eason
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