Why am I getting a data mismatch error when everything has been working perfectly for ages??
The original article I found advised duplicating the table with the error, to replace the original error. This worked. Link to similar article
However, it’s very tedious if you’ve created perspectives, have lots of relationships and calculated columns to rebuild everything. I thought about this more and I release now why this error happened.
The first time you create a table and load it to Power BI, the data types will be auto applied. In my case I planned to concatenate reference values if there was more than one, however, for over a year the data contained only one value, so Power BI had defaulted that field to a whole number.
One year later and the report was erroring out when I tried to refresh it…
Next time to resolve will do the following:
- Duplicate the query & load the duplicated query
2. Now compare data types for columns
To speed this up. I’d check the original SQL query if I must concatenate any values to return a comma delimited list for example.
Change the data type on the column and apply the data refresh. This time works without recreating the whole table.