Connecting & querying

Where the walkers actually live

So far your handlers have returned data you hard-coded in Go. A real PawWalk backend keeps walkers, bookings, and GPS fixes in a database — usually PostgreSQL — that survives restarts and serves many requests at once.

Go talks to SQL databases through one standard-library package: database/sql. It gives you a common API (Query, Exec, Scan) and you plug in a driver for your specific database. Import the package the usual way, and pull in the driver for its side effect of registering itself:

import (

"database/sql"

_ "github.com/lib/pq" // registers the postgres driver

)

The underscore _ means import this only for its side effects — the driver registers the name "postgres" in its init(), and you never call it directly.

lib/pq is perfectly fine for learning database/sql here, but it's now in maintenance mode. For new projects the actively-developed jackc/pgx is the modern Postgres driver of choice — use it directly, or through pgx/stdlib to keep this same database/sql API.