update issues

[JBell1979]

Team, I'm trying to udate my PBI for the new year but I'm getting this message.

"Column 'Month' in Table 'MSL YTD' contains a duplicate value 'January' and this is not allowed for columns on the one side of a many-to-one relationship or for columns that are used as the primary key of a table." 

I am just adding the data from this year to the data from last. 13 rows of data total

Thanks for all the help

~J

[AnkitKukreja · Accepted solution]

Hi @JBell1979 

Try to understand the error, most of the time solution is within: "this is not allowed for columns on the one side of a many-to-one relationship or for columns that are used as the primary key of a table." 

This means you have got a relationship on the Month column from the Date table to another table. Which would have duplicates like the Month of January in this case. You should have the relationship with the  Date column instead to avoid such problems in future because the date would be unique in the date table always.