> ## 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.

# CountRecords

> Returns one integer that represents the count of records in the input dataset

export const gemName_0 = "CountRecords"

export const execution_engine_0 = "the SQL warehouse"

<Info>This gem runs in {execution_engine_0}.</Info>

## Overview

The CountRecords gem allows you to count the number of rows in a dataset in different ways. You can count all rows, count non-null values in selected columns, or count distinct non-null values in selected columns.

<Tip>
  The {gemName_0} gem has a corresponding interactive gem example. See [Interactive gem
  examples](/data-analysis/gems/gems#interactive-gem-examples) to learn how to run sample pipelines
  for this and other gems.
</Tip>

## Prerequisites

* Add `prophecy_basics` package version 1.0.0 or higher to your project.

## Input and Output

The CountRecords gem accepts the following input and output.

| Port    | Description                                                                                |
| ------- | ------------------------------------------------------------------------------------------ |
| **in0** | Input dataset with the columns to count.                                                   |
| **out** | Output dataset with the resulting count(s). Output has one row with the selected count(s). |

## Parameters

Configure the CountRecords gem using the following parameters.

| Parameter               | Description                                                                               |
| ----------------------- | ----------------------------------------------------------------------------------------- |
| Count option            | Choose how the data should be counted. See [Count options](#count-options) below.         |
| Select columns to count | One or more columns to count. Required for counting non-null records or distinct records. |

### Count options

Choose one of the following strategies for counting records.

| Strategy                                     | Description                                                                   |
| -------------------------------------------- | ----------------------------------------------------------------------------- |
| Count number of total records                | Returns the total number of rows in the input dataset, including null values. |
| Count non-null records in selected column(s) | Returns the number of non-null rows for each selected column.                 |
| Count distinct records in selected column(s) | Returns the number of distinct, non-null values for each selected column.     |

## Example

Given a table of patient visits:

<div class="table-example">
  | PatientID | VisitDate  | Department | Diagnosis |
  | --------- | ---------- | ---------- | --------- |
  | 1         | 2024-01-01 | Cardiology | Flu       |
  | 2         | 2024-01-02 | Oncology   | Cancer    |
  | 3         | 2024-01-03 | Cardiology | Flu       |
  | 4         | 2024-01-04 | NULL       | Cold      |
</div>

If you choose:

* **Count distinct records** on `Department`: the result will be `2` (Cardiology, Oncology).
* **Count non-null records** on `Department`: the result will be `3`.
* **Count total number of records**: the result will be `4`.