We have a column in our Oracle database that has people's ages in it, like 32, 45, 64, whatever. I've verified the data exists by running a manual SQL command.
When I pull this column into Tableau, it shows the range as being from Null to Null.. It's seeing no data at all.
We've tried to refresh the data source, reconnect to it, restart Tableau, none of these help.
We have no filters, even the most simple viz shows nothing for the column.
There are millions of rows in this table, and there's a ton of null values.. Could it be that Tableau is limiting how it looks at the column?
Can we do some trouble shooting using SQL commands within Tableau? How can I see what SQL Tableau is executing?
The SQL is in the log files, under My Tableau Repository.