text: CREATE TABLE Author (
  	-- Author has Author Id
  	AuthorId                                BIGINT NOT NULL GENERATED ALWAYS AS IDENTITY,
  	-- Author is called Name
  	AuthorName                              VARCHAR(64) NOT NULL,
  	-- Primary index to Author(Author Id in "Author has Author Id")
  	PRIMARY KEY(AuthorId),
  	-- Unique index to Author(Author Name in "author-Name is of Author")
  	UNIQUE(AuthorName)
  );
  
  
  CREATE TABLE Comment (
  	-- Comment has Comment Id
  	CommentId                               BIGINT NOT NULL GENERATED ALWAYS AS IDENTITY,
  	-- Comment was written by Author that has Author Id
  	AuthorId                                BIGINT NOT NULL,
  	-- Comment consists of text-Content and maybe Content is of Style
  	ContentStyle                            VARCHAR(20) NULL,
  	-- Comment consists of text-Content and Content has Text
  	ContentText                             VARCHAR(MAX) NOT NULL,
  	-- Comment is on Paragraph that involves Post that has Post Id
  	ParagraphPostId                         BIGINT NOT NULL,
  	-- Comment is on Paragraph that involves Ordinal
  	ParagraphOrdinal                        INTEGER NOT NULL,
  	-- Primary index to Comment(Comment Id in "Comment has Comment Id")
  	PRIMARY KEY(CommentId),
  	FOREIGN KEY (AuthorId) REFERENCES Author (AuthorId)
  );
  
  
  CREATE TABLE Paragraph (
  	-- Paragraph involves Post that has Post Id
  	PostId                                  BIGINT NOT NULL,
  	-- Paragraph involves Ordinal
  	Ordinal                                 INTEGER NOT NULL,
  	-- Paragraph contains Content that maybe is of Style
  	ContentStyle                            VARCHAR(20) NULL,
  	-- Paragraph contains Content that has Text
  	ContentText                             VARCHAR(MAX) NOT NULL,
  	-- Primary index to Paragraph(Post, Ordinal in "Post includes Ordinal paragraph")
  	PRIMARY KEY(PostId, Ordinal)
  );
  
  
  CREATE TABLE Post (
  	-- Post has Post Id
  	PostId                                  BIGINT NOT NULL GENERATED ALWAYS AS IDENTITY,
  	-- Post was written by Author that has Author Id
  	AuthorId                                BIGINT NOT NULL,
  	-- Post belongs to Topic that has Topic Id
  	TopicId                                 BIGINT NOT NULL,
  	-- Primary index to Post(Post Id in "Post has Post Id")
  	PRIMARY KEY(PostId),
  	FOREIGN KEY (AuthorId) REFERENCES Author (AuthorId)
  );
  
  
  CREATE TABLE Topic (
  	-- Topic has Topic Id
  	TopicId                                 BIGINT NOT NULL GENERATED ALWAYS AS IDENTITY,
  	-- Topic is called topic-Name
  	TopicName                               VARCHAR(64) NOT NULL,
  	-- maybe Topic belongs to parent-Topic and Topic has Topic Id
  	ParentTopicId                           BIGINT NULL,
  	-- Primary index to Topic(Topic Id in "Topic has Topic Id")
  	PRIMARY KEY(TopicId),
  	-- Unique index to Topic(Topic Name in "Topic is called topic-Name")
  	UNIQUE(TopicName),
  	FOREIGN KEY (ParentTopicId) REFERENCES Topic (TopicId)
  );
  
  
  ALTER TABLE Comment
  	ADD FOREIGN KEY (ParagraphPostId, ParagraphOrdinal) REFERENCES Paragraph (PostId, Ordinal);
  
  ALTER TABLE Paragraph
  	ADD FOREIGN KEY (PostId) REFERENCES Post (PostId);
  
  ALTER TABLE Post
  	ADD FOREIGN KEY (TopicId) REFERENCES Topic (TopicId);
  