Grouping Data into Clusters and Subclusters

One extension adds the ability to scan SQL statements for specific field names that signal grouping values to be wrapped into a cluster or subcluster (a cluster within a cluster). The syntax remains pure SQL, but certain field names are reserved and given special meaning.

Clusters and subclusters can specify:

• A mandatory cluster column. The presence of this column triggers the additional processing needed to insert cluster braces into the result set.
• A Label, which allows you to override the label derived from the cluster column. If no label is provided, the value of the cluster column is used.
• A Style Name, which must correspond to a style defined on the styles worksheet. This can be:
  • a static string
  • a composite string using substitution or concatenation
  • or a column value that matches a style name
    A common example appears in heat‑map scenarios, where values such as Critical and Standard map to styles of the same name, each with its own fill color.
• Attributes, which allow you to include line‑specific attribute values.
• Tooltip, which provides hover text in SVG output.

Although the examples below use uppercase for clarity, the implementation is case‑insensitive. Variants such as CLUSTER, Cluster, ClUsTeR, and cluster are all treated identically.

Column	Cluster Field Names	Subcluster Field Names
cluster column (i.e., group by)	CLUSTER	SUBCLUSTER
Label	CLUSTER LABEL	SUBCLUSTER LABEL
Style Name	CLUSTER STYLE NAME	SUBCLUSTER STYLE NAME
Attributes	CLUSTER ATTRIBUTES	SUBCLUSTER ATTRIBUTES
Tooltip	CLUSTER TOOLTIP	SUBCLUSTER TOOLTIP