--database注释
COMMENT ON DATABASE foodb IS '样例数据库';
--表注释
COMMENT ON TABLE foo IS '样例';
--sequence注释
COMMENT ON SEQUENCE foo_seq IS '样例';
--列明注释
COMMENT ON COLUMN foo.foo_id IS 'ID';
COMMENT ON COLUMN foo.foo_name IS '姓名';
COMMENT ON COLUMN foo.foo_category IS '分类;
COMMENT ON COLUMN foo.foo_flg IS '标签';
--注释删除
COMMENT ON COLUMN foo.foo_id IS NULL;