---
url: /technical/datasources.md
description: >-
  A Datasource is a connection to a database or alternative source of
  information (such as a file-system), it holds the authentication information
  as needed.
---

# What is a Datasource

A Datasource is a connection to a database or alternative source of information (such as a file-system), it holds the authentication information as needed. Datasources are used primarily by Processes and Server Pages to retreive and store information from the given Datasource.

## Datasource Types

| Type | Description |
| :--- | :--- |
| Database | These are direct connections to a source database. Accessible on a public IP address or after establishing a Virtual Private Network (VPN). |
| File-System | This is a direct link to the files system on a given instance. This Datasouce is used when text files have been uploaded to the instance. |

## Datasource Usage

### Datasource for a Process

Datasources are primarily used by processes as the source of the information they process. Database type Datasources support both sourcing a full table of information or data from a user-input `SQL` query.

**Process with the `Internal Datastore` Datasource selected.**
![The Data tab of a process, annotated to show the Datasource, Method and Item pickers, Preview, and the rows that data() receives](/process-example-datasource.png)

### Datasource queries in JavaScript

Both Processes and Custom Server Pages can use the scripting functions in jAvaScript to return or modify data from any Database type Datasource.

```js
datasource.insert(datastoreName, query, [...prompts])
datasource.select(datastoreName, query, [...prompts])
datasource.update(datastoreName, query, [...prompts])
```

Here is an example script which selects records from a Datasource using the `datasource.select` function in conjunction with an SQL query.

```js
/*
This example will run the following SQL query and return 
    the results as an array of objects.

    SELECT 
        account_code, 
        account_name, 
        account_type 
    FROM 
        performance_management.accounts 
    WHERE 
        account_code = 'REV';

The parameterisation is used to ensure all inputs are sanitized 
    from SQL injection and are data integrity is maintained 
    when the function encounters unescaped characters.
*/
let records = JSON.parse(
        datasource.select(
            `Internal Datastore`,
            `SELECT account_code, account_name, account_type FROM 
                performance_management.accounts WHERE account_type = ?`, 
            [`REV`]
        )
    );
console.log(records);
/*
This will log the following:
[
    {"account_code":"43050","account_name":"Revenue - Subscription Sales","account_type":"REV"},
    {"account_code":"43051","account_name":"Revenue - Direct Sales","account_type":"REV"},
    {"account_code":"43052","account_name":"Revenue - Services","account_type":"REV"},
]
*/
```

See [Adding a Datasource](/technical/adding-a-datasource) for how to add a new Datasource to MODLR.