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Computed columns

Derived columns you build from a few dropdowns instead of a formula — days between two dates, the quarter a transaction falls in, a flag for anything over a threshold. They behave like real columns everywhere in Prism, and they never touch your original file.

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The point of them

Reviewing a file usually needs one column the file does not have. Ageing needs days-since-invoice-date. Reporting by period needs a quarter. Spotting exceptions needs a flag for rows over a limit.

In Excel that means a helper column, a formula, and a copy down a hundred thousand rows — in a client's file you would rather not modify. Here you define it once, see a preview against real rows immediately, and the column exists across every view: charts, pivots, filters, quality checks, reports.

One-click presets

Common jobs are single clicks — pick the column, done.

Preset	What it produces
Validate Email	Marks each address Valid or Invalid
Format Phone	Standardises numbers to a consistent format
Email Domain	Extracts the domain from an address — useful as a grouping field
Title Case	Capitalises the first letter of each word
Trim Spaces	Removes leading and trailing whitespace
Extract Year	The year number from a date
Quarter	Q1 / Q2 / Q3 / Q4 from a date
Month Name	January, February, and so on
Age in Years	Years elapsed from a date to today
Round (2dp)	Rounds to two decimal places
Absolute Value	Converts negatives to positives

Building your own

Nine builders cover the rest, each configured from dropdowns rather than syntax:

Builder	What it does	Typical use
Arithmetic	Two columns, or a column and a fixed number, combined with + − × ÷	Quantity × Unit Price; Amount ÷ 11 for a GST component
Date difference	Days, months or years between two dates — or between a date and today	Days overdue; days from order to delivery
Join text	Two columns joined with a separator you choose	Building a composite key from code plus reference
If / then	A condition on one column (equals, not equals, >, <, ≥, ≤) producing a value you specify	Flag every invoice over a threshold for review
Change case	UPPERCASE, lowercase, Title Case, or trim whitespace	Normalising a category before grouping
Date part	Year, month number, month name, quarter or day of month	Grouping a ledger by period
Math function	Rounding, absolute value and similar	Tidying calculated amounts
Validate	Checks a column's values against an expected format	Finding malformed contact details before a mail-out
Extract	Pulls a part out of a value, such as the domain from an email	Turning free text into something groupable

They behave like real columns

A computed column is not a display trick. Once added it can be:

charted, grouped and pivoted like any other column
filtered and sorted in Records
given a role, so a computed amount is treated as Currency and a computed period as Category
included in exports and reports
saved into a recipe and reapplied to next month's file automatically

That last point is the one that compounds: the ageing column you defined in January is part of every subsequent month's review without being rebuilt.

Your original file is never modified. Computed columns exist in the workspace. They appear in exports you deliberately create — a reviewed copy or a report — and nowhere else. Nothing is written back to the file you opened.

A note on ambition

This is deliberately not a formula language. There are no cell references, no nested functions, no macro layer — because a review tool that needs debugging is a review tool nobody trusts. The builders cover the derived columns that recur in file review; anything genuinely bespoke still belongs in Excel, and Prism is designed as the companion to that rather than its replacement.

Add a column and watch it update against your real rows before you commit.

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