Try to build line or area, or coulumn charts. Nothing works.
Update: they work, but only with values explicitly defined as numbers (there was a mistake in my DB).
Next question: how to show several values from different columns in the DB? I see that there is a field “Series” but it works within one column.
Indeed the Chart UI library that we use needs the values to be numbers as in JavaScript Number instances. Using strings won’t work.
Not sure what you mean by showing values from different columns. Do you want to do that in the same chart? As with multiple series types? If yes this is not currently possible.
The Series property is used to group the values by some criteria. For example the demo from this post uses the Series to group the bars by year.