$this - > db - > query("ALTER TABLE properties
     ADD is_manually_created varchar(1) DEFAULT 'N';
     ");  

     $this - > db - > query("ALTER TABLE attachments MODIFY COLUMN file_name VARCHAR(250); ");

     $this - > db - > query("CREATE TABLE `documents` (
       `id`
       int(12) NOT NULL AUTO_INCREMENT,
       `document_type`
       varchar(20) DEFAULT NULL COMMENT 'communication, memo,',
       `description`
       text,
       `received_from`
       varchar(100) DEFAULT NULL,
       PRIMARY KEY(`id`)
     ) ENGINE = InnoDB DEFAULT CHARSET = utf8;
     "); 

     $this - > db - > query("CREATE TABLE `documents_tracking` (
       `id`
       int(12) NOT NULL AUTO_INCREMENT,
       `doc_id`
       int(12) DEFAULT NULL,
       `remarks`
       text,
       `current_division`
       varchar(30) DEFAULT NULL,
       `date_time`
       timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
       `user_id`
       int(12) DEFAULT NULL,
       PRIMARY KEY(`id`)
     ) ENGINE = InnoDB DEFAULT CHARSET = utf8;
     "); 

     $this - > db - > query("ALTER TABLE documents_tracking
       MODIFY COLUMN division varchar(30);
       ");