Oracle動態修改表的字段

--alter table TM_PRODUCT_INFO modify (brief_overview clob);
ALTER TABLE TM_PRODUCT_INFO RENAME COLUMN brief_overview TO brief_overview1;
ALTER TABLE TM_PRODUCT_INFO ADD brief_overview clob;
UPDATE TM_PRODUCT_INFO SET brief_overview = CAST(brief_overview1 AS VARCHAR(1024));
ALTER TABLE TM_PRODUCT_INFO DROP COLUMN brief_overview1;