Tableau function Operators
Parentheses make Tableau evaluate the inside first: ([a] + [b]) * 2 adds before multiplying. They carry over to SQL unchanged. Never drop them because the expression looks the same in SQL: -([a] ^ 2) and -[a] ^ 2 differ in both.
(expression)expressionReturns the value of the inner expression, evaluated before the operators around it.
Each example runs on the same 8 sample rows twice: the Tableau formula on the xmetric engine, and the SQL in DuckDB.
Tableau
([a] + [b]) * 2SQL (DuckDB)
SELECT (a + b) * 2 AS result
FROM input
ORDER BY idRow 1: (7 + 2) * 2 = 18.
| a | b | Result |
|---|---|---|
| 7 | 2 | 18 |
| −7 | 2 | −10 |
| 2 | 5 | 14 |
| 9 | 4 | 26 |
| 5 | 3 | 16 |
| 2 | null | |
| 1 | null | |
| −3 | −2 | −10 |
The Tableau formula and the SQL return the same 8 rows.
Common mistake
-a ^ 2 lose the minus sign?Without parentheses the minus binds first, in Tableau and in DuckDB, so -a ^ 2 is a positive square. -([a] ^ 2) squares first and then negates; keep the parentheses.
Tableau
-([a] ^ 2)Tempting SQL
SELECT - a ^ 2 AS result
FROM input
ORDER BY idSQL that matches
SELECT - (a ^ 2) AS result
FROM input
ORDER BY id| a | Tableau | Tempting SQL | SQL that matches |
|---|---|---|---|
| 7 | −49 | 49 | −49 |
| −7 | −49 | 49 | −49 |
| 2 | −4 | 4 | −4 |
| 9 | −81 | 81 | −81 |
| 5 | −25 | 25 | −25 |
| null | null | null | |
| 1 | −1 | 1 | −1 |
| −3 | −9 | 9 | −9 |
The SQL that matches returns the Tableau result on every row; the marked cells are where the tempting SQL differs.
The first example, written for each warehouse from its documentation. These are not run here; DuckDB is.
Edit the formula and run it on the 8 sample rows. Fields: [id], [a], [b], [x], [p], [q], [s], [t], [d], [e].
Runs in your browser on the xmetric engine. Nothing is uploaded.
No. They only change the result when they change the order of evaluation.
No. A null inside still makes the whole arithmetic result null.