# `union`

## Description

The `union` command concatenates the results from two or more datasets into one dataset. This allows users to combine results from multiple queries into one seamless dataset. One dataset can be a result set piped into the `union` command and then concatenated with another dataset.

## Syntax

```dataprime
<query> | union (<query>)
```

## Example

Combine logs from two different teams into a single dataset to analyze them together.

### Example data

```json
// Logs for Team 58942
{ "id": "111", "name": "John" , "team.id": "58942" }
{ "id": "222", "name": "Emily", "team.id": "58942" }
{ "id": "333", "name": "Alice", "team.id": "58942" }

// Logs for Team 98361
{ "userid": "111", "timestamp": "2022-01-01T12:00:00Z", "team.id": "98361" }
{ "userid": "111", "timestamp": "2022-01-01T12:30:00Z", "team.id": "98361" }
{ "userid": "222", "timestamp": "2022-01-01T13:00:00Z", "team.id": "98361" }
{ "userid": "222", "timestamp": "2022-01-01T13:00:00Z", "team.id": "98361" }
{ "userid": "222", "timestamp": "2022-01-01T13:00:00Z", "team.id": "98361" }
```

### Example query

```dataprime
source logs(teamId='58942')
| union (source logs(teamId='98361'))
```

### Example output

```json
{ "id": "111", "name": "John" , "team.id": "58942" }
{ "id": "222", "name": "Emily", "team.id": "58942" }
{ "id": "333", "name": "Alice", "team.id": "58942" }
{ "userid": "111", "timestamp": "2022-01-01T12:00:00Z", "team.id": "98361" }
{ "userid": "111", "timestamp": "2022-01-01T12:30:00Z", "team.id": "98361" }
{ "userid": "222", "timestamp": "2022-01-01T13:00:00Z", "team.id": "98361" }
{ "userid": "222", "timestamp": "2022-01-01T13:00:00Z", "team.id": "98361" }
{ "userid": "222", "timestamp": "2022-01-01T13:00:00Z", "team.id": "98361" }
```

Note

- Use `union` when you need to **append rows from one dataset to another**.
- To process large datasets, consider using `filter` to limit rows before using `union` to improve performance.

**Limitations:**

- Queries can include a maximum of **10 `union` commands** for Frequent Search data.
- There is **no limit** when operating on archived data.