> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getmateo.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Upsert Data

> Using either POST or PUT, you can upsert rows.

You can upsert data with `POST` and the `Prefer: resolution=merge-duplicates` header:

```bash theme={null}
curl "https://integration.getmateo.com/api/v1/contact" \
  -X POST -H "Content-Type: application/json" \
  -H "Prefer: resolution=merge-duplicates" \
  -d '{ "id": 1, full_name": "Max Mustermann" }'
```

By default, upsert operates based on the primary key columns, you must specify all of them. You can also choose to ignore the duplicates with `Prefer: resolution=ignore-duplicates`.

### On Conflict

By specifying the on\_conflict query parameter, you can make upsert work on a column(s) that has a UNIQUE constraint.

```bash theme={null}
curl "https://integration.getmateo.com/api/v1/contact?on_conflict=external_id" \
  -X POST -H "Content-Type: application/json" \
  -H "Prefer: resolution=merge-duplicates" \
  -d '{ "external_id": 1, full_name": "Max Mustermann" }'
```

### PUT

You can also upsert data with `PUT`:

```bash theme={null}
curl "https://integration.getmateo.com/api/v1/contact?id=eq.123" \
  -X PUT -H "Content-Type: application/json" \
  -d '{ "id": 123, "full_name": "Max Mustermann" }'
```

All the columns must be specified in the request body, including the primary key column(s).

### Response

If the data was inserted, the response status code will be `201 Created`. If the data was updated, the response status code will be `200 OK`.

The response body will be empty by default, but you can add a `select` query parameter to select the columns that should be returned:

```bash theme={null}
curl "https://integration.getmateo.com/api/v1/contact?id=eq.123&select=id,full_name" \
  -X PUT -H "Content-Type: application/json" \
  -d '{ "id": 123, "full_name": "Max Mustermann" }'
```

```json theme={null}
{
  "id": 1234,
  "full_name": "Max Mustermann"
}
```