[Relational Queries] Nullable one-to-one relationship

export const teamsT = mysqlTable("Teams", {
  id: varchar("id", { length: 21 }).primaryKey(),
  name: varchar("name", { length: 40 }).notNull(),
  joinCode: varchar("joinCode", { length: 8 }).notNull(),
});

export const projectsT = mysqlTable("Projects", {
  id: varchar("id", { length: 21 }).primaryKey(),
  teamId: varchar("teamId", { length: 21 }).notNull(),
  name: varchar("name", { length: 40 }).notNull(),
  description: varchar("description", { length: 255 }).notNull(),
  content: text("content").notNull(),
  submitted: boolean("submitted").notNull(),
  submittedTime: timestamp("submittedTime"),
});

export const teamsRelations = relations(teamsT, ({ one, many }) => ({
  project: one(projectsT, {
    fields: [teamsT.id],
    references: [projectsT.teamId],
  }),
}));

export const projectsRelations = relations(projectsT, ({ one, many }) => ({
  team: one(teamsT, {
    fields: [projectsT.teamId],
    references: [teamsT.id],
  }),
}));

const result = await db.query.registrationsT.findFirst({
    where: eq(registrationsT.userId, ctx.user.id),
    columns: {
      id: true,
    },
    with: {
      team: {
        columns: {
          id: true,
          name: true,
        },
        with: {
          project: {
            columns: {
              id: true,
            },
          },
        },
      },
    },
  });

{
  id: number;
  team: { id: string; name: string; project: { id: string } } | null;
} | undefined