---
title: "system.mongodb.replaceOne"
description: "Replaces a document in the collection that matches the filter."
---

# system.mongodb.replaceOne

> Replaces a document in the collection that matches the filter.

This function is used in **Python Scripting**.

:::note
Project Library scripts will not provide hints for MongoDB system functions unless the Script Hint Scope is set to **Gateway**. See the [Scripting in Ignition](platform\scripting\scripting-in-ignition\scripting-in-ignition.md#system-functions-hints-and-autocomplete) page for more details on scripting hints.
:::

## Description
## Client Permission Restrictions
This scripting function has no [Client Permission](../../../ignition-modules/vision/vision-project-properties/vision-project-properties.md#vision-permissions-properties) restrictions.

## Syntax
`system.mongodb.replaceOne(connector, collection, filter, replacement, [options])`

### Parameters
Type | Parameter | Description 
------- | ------- | ------
String| `connector` | The name of connector (case-insensitive).
String| `collection` | The name of collection (case-sensitive).
PyDictionary| `filter` | A PyDictionary for specifying matching key value pair criteria when querying a collection.
PyDictionary| `replacement` | New values to apply for all non-immutable document fields. 
PyDictionary| `options` | A PyDictionary for including additional replace configurations. [optional]

### Returns
**PyDictionary** `result` - Result of replace action formatted as a PyDictionary with keys ‘acknowledged’, ‘modifiedCount’, ‘matchedCount’, and ‘upsertedId’.

### Scope
Gateway, Perspective Session

## Code Examples
```python title="Example #1"
# Import required BSON types.
from system.mongodb.types import ObjectId
 
# Specify unique field values to locate specific document. Here we are specifying the known _id of the document.
filter = {"_id": ObjectId("63fe3941519feb58abb3cda1")}
 
# Specify required fields in a PyDictionary format for BSON document.
replacement = {
                    "username": "jdoe2",
                    "name": "Jane Doe II",
                    "address": '321 Second Street, City CA 56789',
                    "birthdate": system.date.getDate(2004, 5, 19),
                    "email": "jdoe2@email.com",
                    "active": True,
                    "accounts": [],
                    "tier_and_details": {}
                }
 
   
# Apply parameters for function call.
print system.mongodb.replaceOne("MongoDB", "customers", filter, replacement)
```