Calculations

A calculation works a value out from other values, so nobody has to type it or keep it correct by hand. In Sterodata you write one as a formula field: a column whose value on each row comes from that row's other fields and from the records it links to. Its value is worked out whenever the table is read, so it follows every change to the values it uses.

In this section

• Formulas: adding a formula field, how a formula is written, field names, linked records, text, numbers, conditions and empty values.
• Functions: every function a formula can use, what each takes and what it gives back, with an example.
• Dates and time: today's date, a date plus or minus a number of days, the days between two dates, and the parts of a date.
• Money and currencies: amounts in several currencies, where exchange rates come from, and how rows and totals are converted.
• What-if: change an input and watch the calculations move, without saving anything.

Formula, lookup or rollup

Two field types cover common calculations without a formula. Both are described in Fields.

• A Lookup shows a field of the linked record as a column of its own: the customer's city on each order.
• A Rollup works out a total over the records that link to this one: the sum of an order's lines, how many payments an invoice has, the latest visit.

Use a formula when you need to do something with values: multiply them, compare them, choose between two answers, count days or join text. A formula reads a lookup's value and a rollup's result like any other field. It can also read a field of a linked record directly, with a dot (Customer.City), so you do not need a lookup just to use a value in a calculation.

To group many rows and add them up, by region or by month for example, use a summary. Summaries are described in Views.

In this section

• FormulasAdd a formula field, then write the formula: field names, fields of linked records, text, numbers, conditions and empty values.
• FunctionsEvery function a formula can use, grouped by kind: what each takes, what it gives back, and an example you can copy.
• Dates and timeUse today's date in a formula, add or take away days, count the days between two dates, and read the year, month or day of a date.
• Money and currenciesKeep amounts in several currencies, choose where exchange rates come from, and see how each row and each total is converted.
• What-ifChange an input a formula reads, such as a rate or a discount, and watch every calculation that depends on it move, without saving anything.