text: -- Your SQL goes here
  CREATE TYPE TSentenceType AS ENUM ('origin','translation','relation');
  
  CREATE TABLE sentences (
      id           SERIAL PRIMARY KEY,
      is_pr        BOOL  DEFAULT(FALSE),
      block_id     INTEGER ,
  
      channel_id   INTEGER ,
      book_id      INTEGER  NOT NULL,
      paragraph    INTEGER  NOT NULL,
      word_start        INTEGER  NOT NULL,
      word_end        INTEGER  NOT NULL,
  
      content      TEXT,
      content_type TContentType NOT NULL DEFAULT('markdown'), 
      
      type         TSentenceType NOT NULL DEFAULT('translation'), 
      lang         VARCHAR (16) NOT NULL DEFAULT('en'),
      status TStatus  NOT NULL DEFAULT('private'), 
  
      editor_id INTEGER  NOT NULL,
      owner_id INTEGER  NOT NULL,
  
  	version     INTEGER NOT NULL DEFAULT (1),
      deleted_at  TIMESTAMP,
  
      created_at  TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
      updated_at  TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
  );
  
  
  CREATE INDEX sentences_unique ON sentences ("channel_id","book_id","paragraph","word_start","word_end");
  
  