docs/tutorials/tutorial-msq-extern.md

---
id: tutorial-msq-extern
title: Load files with SQL-based ingestion
sidebar_label: Load files using SQL
description: How to generate a query that references externally hosted data
---

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:::info
 This page describes SQL-based batch ingestion using the [multi-stage query (MSQ) task engine](../multi-stage-query/index.md).
 Refer to the [ingestion methods](../ingestion/index.md#batch) table to determine which ingestion method is right for you.
:::

This tutorial demonstrates how to generate a query that references externally hosted data using the **Connect external data** wizard.

The following example uses EXTERN to query a JSON file located at https://druid.apache.org/data/wikipedia.json.gz.

Although you can manually create a query in the UI, you can use Druid to generate a base query for you that you can modify to meet your requirements.

To generate a query from external data, do the following:

1. In the **Query** view of the web console, click **Connect external data**.
2. On the **Select input type** screen, choose **HTTP(s)** and enter the following value in the **URIs** field: `https://druid.apache.org/data/wikipedia.json.gz`. Leave the HTTP auth username and password blank.
3. Click **Connect data**.
4. On the **Parse** screen, you can perform additional actions before you load the data into Druid:
   - Expand a row to see what data it corresponds to from the source.
   - Customize how Druid handles the data by selecting the **Input format** and its related options, such as adding **JSON parser features** for JSON files.
5. When you're ready, click **Done**. You're returned to the **Query** view where you can see the starter query that will insert the data from the external source into a table named `wikipedia`.

   <details>
   <summary>Show the query</summary>

   ```sql
   REPLACE INTO "wikipedia" OVERWRITE ALL
   WITH ext AS (SELECT *
   FROM TABLE(
     EXTERN(
       '{"type":"http","uris":["https://druid.apache.org/data/wikipedia.json.gz"]}',
       '{"type":"json"}',
       '[{"name":"isRobot","type":"string"},{"name":"channel","type":"string"},{"name":"timestamp","type":"string"},{"name":"flags","type":"string"},{"name":"isUnpatrolled","type":"string"},{"name":"page","type":"string"},{"name":"diffUrl","type":"string"},{"name":"added","type":"long"},{"name":"comment","type":"string"},{"name":"commentLength","type":"long"},{"name":"isNew","type":"string"},{"name":"isMinor","type":"string"},{"name":"delta","type":"long"},{"name":"isAnonymous","type":"string"},{"name":"user","type":"string"},{"name":"deltaBucket","type":"long"},{"name":"deleted","type":"long"},{"name":"namespace","type":"string"},{"name":"cityName","type":"string"},{"name":"countryName","type":"string"},{"name":"regionIsoCode","type":"string"},{"name":"metroCode","type":"long"},{"name":"countryIsoCode","type":"string"},{"name":"regionName","type":"string"}]'
     )
   ))
   SELECT
     TIME_PARSE("timestamp") AS __time,
     isRobot,
     channel,
     flags,
     isUnpatrolled,
     page,
     diffUrl,
     added,
     comment,
     commentLength,
     isNew,
     isMinor,
     delta,
     isAnonymous,
     user,
     deltaBucket,
     deleted,
     namespace,
     cityName,
     countryName,
     regionIsoCode,
     metroCode,
     countryIsoCode,
     regionName
   FROM ext
   PARTITIONED BY DAY
   ```
   </details>

6. Review and modify the query to meet your needs. For example, you can rename the table or change segment granularity. To partition by something other than ALL, include `TIME_PARSE("timestamp") AS __time` in your SELECT statement.

   For example, to specify day-based segment granularity, change the partitioning to `PARTITIONED BY DAY`:

     ```sql
      INSERT INTO ...
      SELECT
        TIME_PARSE("timestamp") AS __time,
      ...
      ...
      PARTITIONED BY DAY
     ```

1. Optionally, select **Preview** to review the data before you ingest it. A preview runs the query without the REPLACE INTO clause and with an added LIMIT.
   You can see the general shape of the data before you commit to inserting it.
   The LIMITs make the query run faster but can cause incomplete results.
2. Click **Run** to launch your query. The query returns information including its duration and the number of rows inserted into the table.

## Query the data

You can query the `wikipedia` table after the ingestion completes.
For example, you can analyze the data in the table to produce a list of top channels:

```sql
SELECT
  channel,
  COUNT(*)
FROM "wikipedia"
GROUP BY channel
ORDER BY COUNT(*) DESC
```

With the EXTERN function, you could run the same query on the external data directly without ingesting it first:

<details>
<summary>Show the query</summary>

```sql
SELECT
  channel,
  COUNT(*)
FROM TABLE(
  EXTERN(
    '{"type": "http", "uris": ["https://druid.apache.org/data/wikipedia.json.gz"]}',
    '{"type": "json"}',
    '[{"name": "added", "type": "long"}, {"name": "channel", "type": "string"}, {"name": "cityName", "type": "string"}, {"name": "comment", "type": "string"}, {"name": "commentLength", "type": "long"}, {"name": "countryIsoCode", "type": "string"}, {"name": "countryName", "type": "string"}, {"name": "deleted", "type": "long"}, {"name": "delta", "type": "long"}, {"name": "deltaBucket", "type": "string"}, {"name": "diffUrl", "type": "string"}, {"name": "flags", "type": "string"}, {"name": "isAnonymous", "type": "string"}, {"name": "isMinor", "type": "string"}, {"name": "isNew", "type": "string"}, {"name": "isRobot", "type": "string"}, {"name": "isUnpatrolled", "type": "string"}, {"name": "metroCode", "type": "string"}, {"name": "namespace", "type": "string"}, {"name": "page", "type": "string"}, {"name": "regionIsoCode", "type": "string"}, {"name": "regionName", "type": "string"}, {"name": "timestamp", "type": "string"}, {"name": "user", "type": "string"}]'
  )
)
GROUP BY channel
ORDER BY COUNT(*) DESC
```

</details>

## Further reading

See the following topics to learn more:

* [SQL-based ingestion overview](../multi-stage-query/index.md) to further explore SQL-based ingestion.
* [SQL-based ingestion reference](../multi-stage-query/reference.md) for reference on context parameters, functions, and error codes.