const postsByCategory = await  db.select().from(categories)
    .leftJoin(postsOnCategories, eq(categories.id, postsOnCategories.categoryId))
    .leftJoin(posts, eq(postsOnCategories.postId, posts.id))
    .where(eq(categories.id, 3))

const postsByCategory = await  db.select().from(categories)
    .leftJoin(postsOnCategories, eq(categories.id, postsOnCategories.categoryId))
    .leftJoin(posts, eq(postsOnCategories.postId, posts.id))
    .where(eq(categories.id, 3))