# Transforming Data
Your incoming data may have a different data structure, in which case you will need to transform it to allow each item to be processed individually.
For example, the image below shows the output of an HTTP Request node that returns data incompatible with n8n’s data structure. The node returns the data and displays that only one item was returned.
Note: If you’re using the HTTP Request node, you should use the Split Into items option to transform the data. You don’t have to use a Function node in that case.
# Merging items
You might want to merge items together in your workflows. For example when your data contains hundreds of items that you don't want to process individually.
In such cases, merge all items into a single item and process just that one. Use this code snippet in the Function node to transform the data as shown below:
There are three different use cases for merging items:
- Merge items returned by different nodes: If you want to merge items returned by different nodes, use the Merge node.
- Merge items of different executions: You can also merge items that get returned in different executions. Refer to this workflow (opens new window) to learn how: