Field wells
The three wells, what belongs in each, and the Power BI settings that change what the visual receives.
The three wells
| Well | Accepts | Use it for |
|---|---|---|
| Data fields | Table columns | Identifiers, connections, types, labels, diagram IDs, and any column you want in the Node Inspector. Nothing here is summarised. |
| Values | Measures and numeric columns | Probability, failure rate, frequency, health and other numbers the diagram shows or is formatted by. Columns here also show in tooltips. |
| Tooltips | Columns and measures | Detail shown on hover and in the Node Inspector. Nothing in this well changes the diagram. |
Each well takes up to 100 fields.
Set numeric columns to Don't summarize
Power BI sums a numeric column in Values or Tooltips by default, adding together every row that matches in the other columns. A probability summed across twelve monthly snapshots is no longer a probability. Set each numeric column in Values and Tooltips to Don't summarize. Always use Don't summarize explains how to spot a summarised column and how to stop it happening in every report.
A column in the wrong well
An identifier dropped into Values arrives as a measure, which Node ID cannot accept. The visual names the column and the well it belongs in rather than leaving the diagram blank without a reason.
Columns with no role
Bind any column you want available on the diagram. A column that is not mapped to a role is kept on the node, shown in the Node Inspector, and can be used by conditional formatting and value annotations. To show it on hover as well, put it in Values or Tooltips rather than Data fields.