set and get now work trough endpoint api

internal/database/currency.go

@@ -19,3 +19,15 @@ func GetCurrencyByID(db *sql.DB, ID int) (model.Currency, error) {
 	}
 	return c, nil
 }
+
+func GetCurrencyByCode(db *sql.DB, Code string) (model.Currency, error) {
+	var c model.Currency
+	err := db.QueryRow(
+		`SELECT id, code, name, FROM currencies WHERE code = ?`,
+		Code,
+	).Scan(&c.ID, &c.Code, &c.Name)
+	if err == sql.ErrNoRows {
+		return c, fmt.Errorf("company %d not found", Code)
+	}
+	return c, nil
+}