---
title: "SessionIdentifier"
slug: "sessionidentifier"
updated: 2022-02-10T19:45:47Z
published: 2022-02-10T19:45:48Z
canonical: "docs.datajet.app/sessionidentifier"
---

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

# SessionIdentifier

## General: SessionIdentifier

## On a foreign (many-side) table, for the set of records corresponding to each key in the primary (one-side) table, create a sequence counter (an integer discrete field) for each set of records where the elapsed timestamp since the last entry seen is less than the specified duration, in seconds.

## Purpose

Use this function to:

- Organise timestamped data into user sessions of specified duration

## Return Value

| Property | Value |
| --- | --- |
| **FieldType** | Integer |
| **FieldSize** | Continuous |
| **DataType** | Continuous |
| **DataSize** | Integer |

```shell
Example Return Value: 1.....N where N is the number of individual sessions that are identified.
```

## Parameters

| Parameter | JSON | Description |
| --- | --- | --- |
| **Table** | “targetTable”: “MyTableName” | The target table on which the new field will be created |
| **Filter** | “dataset”: {DataSet_JSON} | Optional. If a filter is applied, records not in the filter recordset will be returned as null. |
| **Function** | "function":"sessionidentifier" | SessionIdentifier |
| **Primary Table** | “p1”: “PrimaryTableName” | A primary table that is linked to the target table on the key identifier. For example, if Table = [transactions], Primary Table could be [customer], where the 2 tables are linked on [cid] [transactions].[cid] ->[customer].[cid] |
| **Timestamp** | “p2”:"DateTimeFieldName" | Required. The DateTime Field to use for calculating session intervals. *Supports:* - **DataType:** Continuous - **Field Type:** DateTime |
| **Duration Secs** | “p3”:"#120" | Required. The number of seconds in a session. *Supports:* - **DataType:** - **Field Type:** - **Fixed Value:** For the specified primary key (e.g., cid=123): - If *[Record2_Timestamp - Record1_Timestamp]* is greater than [Duration Secs], then a new session identifier will be given to the current record. - If *[Record2_Timestamp - Record1_Timestamp]* is less than [Duration Secs] then the current record will be given the same session identifier as the previous record. Duration Secs must be provided in the format #N. e.g., - #120 = 2 minutes - #600 = 10 minutes |

## JSON Sample

```json
{
  "method": "BuildBakedField",
  "project": "Internet1",
  "targetTable": "webaction",
  "overwrite": true,
  "name": "Session_10mins",
  "function": "sessionidentifier",
  "p1": "UniqueUser",
  "p2": "timestamp",
  "p3": "#600"
}
```

## Usage Notes

See Also:

- Engineering | Expression Field
- DateTime fields

## Example

| Example | Details |
| --- | --- |
| **Description** | **Group user transactions into sessions of no more than 2 mins inactivity** |
| **Input** | - Table: = [transactions] - Filter: = [No Filter] - **Function: = SessionIdentifier** - Primary Table:= customer - Timestamp:= TimeStampe - Duraton Secs:= #120 - Name: =Session_2mins |
| **Sample** | ![](https://cdn.document360.io/73b6469b-c1e4-47e9-aa65-986c8ebd17ca/Images/Documentation/Gen_SessionIdentifier_Example.png) |