Add database schema for trips, students, parents, and constraints

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"database/sql"
+	_ "embed"
 	"fmt"
 	"log"
 	"net/http"
@@ -10,6 +11,9 @@ import (
 	_ "github.com/lib/pq"
 )
 
+//go:embed schema.sql
+var schema string
+
 func main() {
 	dsn := os.Getenv("PGCONN")
 	if dsn == "" {
@@ -27,6 +31,10 @@ func main() {
 	}
 	log.Println("connected to database")
 
+	if _, err := db.Exec(schema); err != nil {
+		log.Fatalf("failed to apply schema: %v", err)
+	}
+
 	http.Handle("/", http.FileServer(http.Dir("static")))
 
 	http.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {

schema.sql

@@ -0,0 +1,45 @@
+DO $$ BEGIN
+    CREATE TYPE constraint_kind AS ENUM ('happy', 'ok', 'never');
+EXCEPTION WHEN duplicate_object THEN NULL;
+END $$;
+
+DO $$ BEGIN
+    CREATE TYPE constraint_level AS ENUM ('student', 'parent', 'admin');
+EXCEPTION WHEN duplicate_object THEN NULL;
+END $$;
+
+CREATE TABLE IF NOT EXISTS trips (
+    id BIGSERIAL PRIMARY KEY,
+    name TEXT NOT NULL
+);
+
+CREATE TABLE IF NOT EXISTS trip_admins (
+    id BIGSERIAL PRIMARY KEY,
+    trip_id BIGINT NOT NULL REFERENCES trips(id) ON DELETE CASCADE,
+    email TEXT NOT NULL,
+    UNIQUE(trip_id, email)
+);
+
+CREATE TABLE IF NOT EXISTS students (
+    id BIGSERIAL PRIMARY KEY,
+    trip_id BIGINT NOT NULL REFERENCES trips(id) ON DELETE CASCADE,
+    name TEXT NOT NULL,
+    email TEXT NOT NULL,
+    UNIQUE(trip_id, email)
+);
+
+CREATE TABLE IF NOT EXISTS parents (
+    id BIGSERIAL PRIMARY KEY,
+    student_id BIGINT NOT NULL REFERENCES students(id) ON DELETE CASCADE,
+    email TEXT NOT NULL,
+    UNIQUE(student_id, email)
+);
+
+CREATE TABLE IF NOT EXISTS roommate_constraints (
+    id BIGSERIAL PRIMARY KEY,
+    student_a_id BIGINT NOT NULL REFERENCES students(id) ON DELETE CASCADE,
+    student_b_id BIGINT NOT NULL REFERENCES students(id) ON DELETE CASCADE,
+    kind constraint_kind NOT NULL,
+    level constraint_level NOT NULL,
+    UNIQUE(student_a_id, student_b_id, level)
+);