My Original tables are:

CREATE TABLE authors (
    id SERIAL PRIMARY KEY,
    name VARCHAR(255) NOT NULL
);

CREATE TABLE author_details (
    id SERIAL PRIMARY KEY,
    bio TEXT,
    email VARCHAR(255),
    website VARCHAR(255),
    profile_picture BYTEA,
    author_id INTEGER NOT NULL REFERENCES authors(id) ON DELETE CASCADE
);

CREATE TABLE posts (
    id SERIAL PRIMARY KEY,
    title VARCHAR(255) NOT NULL,
    tag TEXT[],
    body TEXT NOT NULL,
    author_id INTEGER NOT NULL REFERENCES authors(id) ON DELETE CASCADE
);

Could you help me to change the tag column of posts to array of inters which will points to another tag_details such as

CREATE TABLE tags_details (
    id SERIAL PRIMARY KEY,
    name: VARCHAR(255) NOT NULL,
    description  TEXT,
);

And modify posts table to limit the tag column reference to tag_details id.

CREATE TABLE tags_details ( id SERIAL PRIMARY KEY, name VARCHAR(255) NOT NULL, description TEXT );

ALTER TABLE posts ADD COLUMN tag_ids INTEGER[] DEFAULT '{}';

ALTER TABLE posts ALTER COLUMN tag_ids SET DATA TYPE INTEGER[] USING (SELECT ARRAY(SELECT id FROM tags_details WHERE name = ANY(tag)));

ALTER TABLE posts DROP COLUMN tag;

So, is this OK? not quite sure the SET DATA TYPE INTEGER[] USING (SELECT ARRAY(SELECT id FROM tags_details WHERE name = ANY(tag))); is in the right place?

CREATE TABLE authors (
    id SERIAL PRIMARY KEY,
    name VARCHAR(255) NOT NULL
);

CREATE TABLE author_details (
    id SERIAL PRIMARY KEY,
    bio TEXT,
    email VARCHAR(255),
    website VARCHAR(255),
    profile_picture BYTEA,
    author_id INTEGER NOT NULL REFERENCES authors(id) ON DELETE CASCADE
);

CREATE TABLE posts (
    id SERIAL PRIMARY KEY,
    title VARCHAR(255) NOT NULL,
    tag_ids INTEGER[] DEFAULT '{}' SET DATA TYPE INTEGER[] USING (SELECT ARRAY(SELECT id FROM tags_details WHERE name = ANY(tag)));,
    body TEXT NOT NULL,
    author_id INTEGER NOT NULL REFERENCES authors(id) ON DELETE CASCADE
);

CREATE TABLE tags_details (
    id SERIAL PRIMARY KEY,
    name VARCHAR(255) NOT NULL,
    description TEXT
);

CREATE TABLE authors (
    id SERIAL PRIMARY KEY,
    name VARCHAR(255) NOT NULL
);

CREATE TABLE author_details (
    id SERIAL PRIMARY KEY,
    bio TEXT,
    email VARCHAR(255),
    website VARCHAR(255),
    profile_picture BYTEA,
    author_id INTEGER NOT NULL REFERENCES authors(id) ON DELETE CASCADE
);

CREATE TABLE tags_details (
    id SERIAL PRIMARY KEY,
    name VARCHAR(255) NOT NULL,
    description TEXT
);

CREATE TABLE posts (
    id SERIAL PRIMARY KEY,
    title VARCHAR(255) NOT NULL,
    tag_ids INTEGER[] DEFAULT '{}',
    body TEXT NOT NULL,
    author_id INTEGER NOT NULL REFERENCES authors(id) ON DELETE CASCADE
);

ALTER TABLE posts ALTER COLUMN tag_ids SET DATA TYPE INTEGER[] USING (SELECT ARRAY(SELECT id FROM tags_details WHERE name = ANY(tag)));

• If you like to accomplish the same thing using rails generate mopdel on all the authors, author_details, posts and tag_details, how to do it pleease.
  • Sure, here are the steps to achieve the same thing using Rails:

1. Generate a new Rails project:

rails new myapp

2. Generate the Author and AuthorDetail models:

rails generate model Author name:string
rails generate model AuthorDetail bio:text email:string website:string profile_picture:binary author:references

This will create two migration files that define the authors and author_details tables.

3. Edit the author_details migration file to add the foreign key constraint:

class CreateAuthorDetails < ActiveRecord::Migration[6.1]
  def change
    create_table :author_details do |t|
      t.text :bio
      t.string :email
      t.string :website
      t.binary :profile_picture
      t.references :author, null: false, foreign_key: true

      t.timestamps
    end
  end
end

4. Generate the TagDetail model:

rails generate model TagDetail name:string description:text

This will create a migration file that defines the tag_details table.

5. Generate the Post model:

```rb
rails generate model Post title:string body:text author:references

This will create a migration file that defines the posts table.

6. Edit the posts migration file to add the tag_ids column and the foreign key constraint:

class CreatePosts < ActiveRecord::Migration[6.1]
  def change
    create_table :posts do |t|
      t.string :title
      t.text :body
      t.references :author, null: false, foreign_key: true
      t.integer :tag_ids, array: true, default: []

      t.timestamps
    end
  end
end

7. Create the database tables:

rails db:create
rails db:migrate

8. Update the Post model to use the tag_details table:

class Post < ApplicationRecord
  belongs_to :author
  has_and_belongs_to_many :tag_details
end

9. Generate the TagDetail migration to create the join table between posts and tag_details:

rails generate migration CreateJoinTablePostTagDetail post tag_detail

10. Edit the CreateJoinTablePostTagDetail migration to define the join table:

class CreateJoinTablePostTagDetail < ActiveRecord::Migration[6.1]
  def change
    create_join_table :posts, :tag_details do |t|
      t.index [:post_id, :tag_detail_id]
      t.index [:tag_detail_id, :post_id]
    end
  end
end

11. Update the TagDetail model to use the join table:

class TagDetail < ApplicationRecord
  has_and_belongs_to_many :posts
end

That's it! You can now use the Rails console or write application code to create, read, update, and delete records in the authors, author_details, posts, and tag_details tables, and associate them using the foreign key and join table constraints.

Regenerate response