一、MYSQL

二、ORACLE

三、DB2

//给表中添加列和列说明
alter table table_name add column  column_name  varchar(20);
comment  on  column  table_name.column_name   is  'XXXXX'

//查询表中列的说明
select t.Remarks as  注释, t.COLNAME from syscat.COLUMNS t where tabschema='table_schema' and TABNAME=upper('table_name');

 

//给表中添加列和列说明alter table table_name add column  COLUMN_name varchar(20);comment  on  column  table_name.COLUMN_name   is  'XXXXX'
//查询表中列的说明select t.Remarks as  注释, t.COLNAME from syscat.COLUMNS t where tabschema='table_schema' and TABNAME=upper('table_name');