你不必这么做 ALTER 评论。只是使用

COMMENT ON table_name.colname IS '...';

设置新注解。这将自动覆盖旧的注解。
评论不是 ALTER ed或 DROP 佩德。若要删除注解，请使用将其设置为null COMMENT ON .

注解将随着表重命名而“移动”：

# select c.relname table_name, pg_catalog.obj_description(c.oid) as comment

from pg_catalog.pg_class c where c.relname = 'old';
 table_name |   comment   
------------+-------------
 old        | comment old
(1 row)

# alter table old rename to new;

ALTER TABLE

# select c.relname table_name, pg_catalog.obj_description(c.oid) as comment

from pg_catalog.pg_class c where c.relname = 'old';
 table_name | comment 
------------+---------
(0 rows)

# select c.relname table_name, pg_catalog.obj_description(c.oid) as comment

from pg_catalog.pg_class c where c.relname = 'new';
 table_name |   comment   
------------+-------------
 new        | comment old
(1 row)

#