Database basic CRUD (#27)

* started schema

* db schemas beginning

* first db schema gen

* added sqlc generation with go generate and sqlite driver

* i think these dependencies are needed

* added IF NOT EXISTS to create and CRUD for each table

* fixed missing columns

* added missing field

* fixed code generation with sqlc

backend/database/database.go

@@ -1,7 +1,25 @@
 package database
 
-type DB struct{}
+import (
+	"database/sql"
+	"fmt"
 
-func NewDB() (*DB, error) {
-	return &DB{}, nil
+	_ "modernc.org/sqlite"
+)
+
+//go:generate sqlc vet
+//go:generate sqlc generate
+
+type DB struct{
+	db *sql.DB
+}
+
+func NewDB(sqliteDBFilePath string) (*DB, error) {
+	db, err := sql.Open("sqlite", ":memory:")
+	if err != nil {
+		return nil, fmt.Errorf("could not connect to sqlite database: %w", err)
+	}
+	return &DB{
+		db: db,
+	}, nil
 }