text: ALTER TABLE phabricator_project.project
    ADD subprojectPHIDs longblob NOT NULL;
  UPDATE phabricator_project.project
    SET subprojectPHIDs = '[]';
  
  CREATE TABLE phabricator_project.project_subproject (
    projectPHID varchar(64) BINARY NOT NULL,
    subprojectPHID varchar(64) BINARY NOT NULL,
    PRIMARY KEY (subprojectPHID, projectPHID),
    UNIQUE KEY (projectPHID, subprojectPHID)
  ) ENGINE=InnoDB;