How Power BI Desktop detect the relation between the tables

[Ramyzo]

Greeting all ,

i have a question on the table relations in power BI , im following a tutorial on relations on power BI . i made some research and i notice that power bi use the type and the name to detect the relation , but in some cases power BI doesnt detect the relation automatically . that's why i want to know exaclty how power bi detect the relations 

and thanks in advance ! 

[Watsky]

Are you referring to the AutoDetection? If so:

Power BI Desktop looks at column names in the tables you are querying to determine if there are any potential relationships. If there are, those relationships are created automatically. If Power BI Desktop cannot determine with a high level of confidence there is a match, it does not automatically create the relationship. 

https://docs.microsoft.com/en-us/power-bi/desktop-create-and-manage-relationships

[Ramyzo]

Yes the auto detection ! there is a clear relation between my table date and table Sales ! but power BI doesnt detect it automatically only when i fo it manually ! that's why im trying to figure it out how PBI detect these relation 

[Watsky]

Are the two columns you are joining named the same? They should be named the same that includes case sensitivity.

[Ramyzo]

Yep they have the same name and same type im 100% positive and still cant detect auto unless i add it manually 

[v-lili6-msft · Accepted solution]

hi, @Ramyzo 

It seems that Autodetect doesn't work for date field, other format works well.

Regards,

Lin