> ## Documentation Index
> Fetch the complete documentation index at: https://docs.prophecy.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Alteryx Filter Tool > Prophecy Filter Gem

> Mapping between Alteryx’s Filter Tool and Prophecy’s Filter Gem

The [Alteryx Filter tool](https://help.alteryx.com/current/en/designer/tools/preparation/filter-tool.html) and the [Prophecy Filter gem](/data-analysis/gems/prepare/filter) perform the same essential task: selecting rows that satisfy a logical condition. Both evaluate a Boolean expression against each incoming record.

Alteryx outputs two branches (True and False), while Prophecy outputs only the rows where the condition is True. To recreate the False branch, add a second Filter gem with the inverse condition.

## Automated migration results

When Import detects an Alteryx Filter tool:

* It generates a Prophecy **Filter** gem with the same condition.
* The **True** branch becomes the Filter gem’s output dataset.
* The **False** branch is **not automatically created**; users must manually add a second gem if they need to preserve this logic.

## Manually replicate in Prophecy

To recreate Alteryx behavior:

1. Add a **Filter** gem.
2. Enter the condition using SQL/Prophecy syntax (such as `Region = 'Europe' AND JoinDate < current_date()`).
3. Connect the output to downstream gems. This is equivalent to the **True** branch in Alteryx.
4. If you need the **False** branch:

   * Add a second Filter gem.
   * Use the inverse condition, such as:
     `NOT (Region = 'Europe' AND JoinDate < current_date())`.

## Configuration options

In Alteryx, the Filter tool is configured by entering a Boolean expression that determines which rows pass through the tool.

In Prophecy, the equivalent behavior is defined by writing a Boolean expression in the **Filter** gem. Expressions may reference columns, comparison operators, logical operators, and null checks. Prophecy enforces schema-aware validation, so expressions must use types correctly (for example, avoiding comparisons between strings and numbers).

## Output behavior

* Produces a **single** dataset containing only rows where the condition evaluates to **True**.
* Does **not** automatically create a False branch.
* Null comparisons follow SQL behavior and must use `IS NULL`/`IS NOT NULL`.

## Known caveats

* Alteryx’s True/False split is not replicated automatically; users must add a second Filter gem for the False path.
* SQL requires explicit `IS NULL` and `IS NOT NULL`.
* Some Alteryx operators differ from SQL syntax and may require translation.

## Example

### Alteryx Filter tool

Goal: Select customers in Europe with join dates before today.

Expression:
`[Region] = "Europe" AND [JoinDate] < DateTimeToday()`

The **True** output contains matching rows; the **False** output contains all others.

### Prophecy equivalent (Filter gem)

Condition:

`Region = 'Europe' AND JoinDate < current_date()`

The gem's output will contain matching rows (the equivalent of the True branch).

To reproduce the False branch, add a second Filter gem with:

`NOT (Region = 'Europe' AND JoinDate < current_date())`