# Open Sesame Data

THE CLOUD EXPEDITION! · level 7 · chapter 3

Marina drags you toward a glowing doorway. 'Behind here? Public shares — datasets that owners have published for open access, live, queryable, no downloads!' She pulls out a golden key. 'But first, you need to ATTACH the database to your session. One command, and it's yours to query.' Welcome to <span class='feature-highlight'>Attaching Shared Data</span> — using ATTACH to connect public shared databases to your session. Public shares are read-only, zero-copy snapshots — you're querying the owner's shared data without copying it.

## Task

Attach Marina Lake's shared database, then query its species. First run <code>ATTACH IF NOT EXISTS</code> to connect the database, then query the top 10 most populous species showing <b>species_name</b>, <b>population_count</b>, and <b>habitat_preference</b>. Run both statements together — the result from the final SELECT is what gets validated.<br><br>These are <b>public shares</b> — open datasets any MotherDuck user in the same region can attach. No special permissions needed.<br><br><b>Share URL:</b><ul><li><code>dbquacks_marina_lake</code> → <code>md:_share/marina_lake_db/3be07852-dfce-4b29-b415-99c9f7fdcc6a</code></li></ul>

## Hint

Use ATTACH IF NOT EXISTS with the share URL and an alias to connect to a shared database

## Expected result

10 rows with columns: species_name, population_count, habitat_preference from Marina Lake's shared database

## Tables

### `lake_visits` (500 rows)

| column | type |
| --- | --- |
| visit_id | BIGINT |
| duck_id | BIGINT |
| destination_pond | VARCHAR |
| visit_date | DATE |
| purpose | VARCHAR |

### `pondville_events` (50 rows)

| column | type |
| --- | --- |
| event_id | BIGINT |
| event_name | VARCHAR |
| event_date | DATE |
| organizer_id | BIGINT |
| location | VARCHAR |
| attendee_count | BIGINT |

### `pondville_residents` (100 rows)

| column | type |
| --- | --- |
| duck_id | BIGINT |
| name | VARCHAR |
| species | VARCHAR |
| home_pond | VARCHAR |
| age | BIGINT |
| occupation | VARCHAR |
| joined_date | DATE |

### `dbquacks_marina_lake.species`

A table in a MotherDuck share; its columns are not listed here.

## Data

The tables live in a DuckDB database: https://dbquacks.com/data/databases/motherduck_tutorial.duckdb

To query it outside the browser, attach it read-only:

```sql
ATTACH 'https://dbquacks.com/data/databases/motherduck_tutorial.duckdb' AS db (READ_ONLY);
USE db;
```

This level also queries MotherDuck shares, which need a MotherDuck token. On the page, the editor asks for one.

Play it in the browser: https://dbquacks.com/motherduck/7

## Reference

https://motherduck.com/docs/sql-reference/motherduck-sql-reference/attach/