text: -- Your SQL goes here
  CREATE TABLE posts (
    id SERIAL PRIMARY KEY,
    publish_tx_id CHAR(64) NOT NULL unique,
    user_address CHAR(40) NOT NULL,
    file_hash CHAR(64) NOT NULL,
    topic CHAR(40) NOT NULL,
    url VARCHAR(255) NOT NULL,
    update_by_tx_id CHAR(64) NOT NULL DEFAULT '',
    updated_at timestamp NOT NULL
  )
  