# Asking questions against a database

## Simple example: San Francisco street trees

The city of San Francisco maintains a [public dataset of every street tree](https://data.sfgov.org/City-Infrastructure/Street-Tree-List/tkzw-k3nq) in the city. We'll start by loading the current snapshot into a SQLite database and asking questions against it.

Give your coding agent this prompt:

```
Run `uvx sqlite-utils insert --help` to learn how sqlite-utils works, then use it to load https://raw.githubusercontent.com/simonw/sf-tree-history/refs/heads/main/Street_Tree_List.csv into a SQLite database called trees.db with TreeID as the primary key.
```

Once the database is created, browse it with Datasette:

```bash
uvx datasette trees.db
```

Now try asking your coding agent questions about the trees. Here are some to get started:

- What are the ten most common tree species in San Francisco?
- How many trees were planted each year? What was the peak year for planting?
- Which streets have the most trees?
- How many trees are cared for by the city (DPW) vs. private owners?

## Bring your own data

Once you've tried the trees example, the next step is to use the same pattern on a dataset you care about.

Good candidates include:

- A CSV you downloaded from a government open data portal
- An Excel spreadsheet from a records request

Start with a prompt like this:

```
I have a dataset in the current directory. Figure out what format it is, load it into a SQLite database, and then help me explore it.

Use `uvx sqlite-utils --help` if needed.
```

Once the database is built, browse it with Datasette:

```bash
uvx datasette data.db
```

Then start asking questions.