# UNION Jack and the Quest for Set Operations

DB Quacks SQL Tutorial · level 23 · chapter 5

Wizard Merlin appears in a flash! "News of your festival has spread across the multiverse! Northern and Southern Duck Communities from parallel dimensions want to participate, but they have separate registries. Create a unified guest list!"

## Task

Combine results from two duck populations into one unified list by working with 'data/northern_ducks.csv' and 'data/southern_ducks.csv' files. You will be merging data from two separate sources.

## Hint

Look for a set operation that can combine rows from multiple SELECT statements.

## Expected result

A unified list of ducks from both northern and southern populations.

## Tables

### `duck_diaries` (10 rows)

| column | type |
| --- | --- |
| diary_id | BIGINT |
| duck_id | BIGINT |
| entry_date | DATE |
| diary_text | VARCHAR |
| mood | VARCHAR |

### `duck_surveys` (5000 rows)

| column | type |
| --- | --- |
| survey_id | BIGINT |
| duck_id | BIGINT |
| age | BIGINT |
| favorite_food | VARCHAR |
| favorite_pond | BIGINT |
| swimming_rating | BIGINT |
| migration_preference | VARCHAR |
| social_behavior | VARCHAR |
| health_status | VARCHAR |
| activity_level | VARCHAR |
| survey_date | DATE |
| survey_location | BIGINT |

### `ducks` (15 rows)

| column | type |
| --- | --- |
| id | BIGINT |
| name | VARCHAR |
| age | BIGINT |
| species | VARCHAR |
| birth_date | DATE |
| arrival_date | DATE |

### `ponds` (3 rows)

| column | type |
| --- | --- |
| pond_id | BIGINT |
| pond_name | VARCHAR |
| location_lat | DOUBLE |
| location_lng | DOUBLE |
| capacity | BIGINT |
| features | VARCHAR[] |
| amenities | VARCHAR[] |

## Files

### `data/northern_ducks.csv` (9 rows)

Download: https://dbquacks.com/data/northern_ducks.csv

| column | type |
| --- | --- |
| name | VARCHAR |
| region | VARCHAR |
| population_id | BIGINT |
| migration_pattern | VARCHAR |

### `data/southern_ducks.csv` (9 rows)

Download: https://dbquacks.com/data/southern_ducks.csv

| column | type |
| --- | --- |
| name | VARCHAR |
| region | VARCHAR |
| population_id | BIGINT |
| migration_pattern | VARCHAR |

## Data

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

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

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

Play it in the browser: https://dbquacks.com/tutorial/23

## Reference

https://duckdb.org/docs/stable/sql/query_syntax/setops.html