alter table case_basicinfo rename column staff_id to staff_id_bak;
alter table case_basicinfo add staff_id clob;
update case_basicinfo set staff_id=staff_id_bak;
alter table case_basicinfo drop column staff_id_bak;
alter table case_basicinfo rename column staff_id to staff_id_bak;
alter table case_basicinfo add staff_id clob;
update case_basicinfo set staff_id=staff_id_bak;
alter table case_basicinfo drop column staff_id_bak;