-- 解除锁表
CALL SYSPROC.ADMIN_CMD('REORG TABLE BS_DOC_CONTRACT_INFO');

-- 添加字段
alter table BS_CREDIT_AGREEMENT_MASTER add MARGIN_PROPORTION DECIMAL(18,6);
comment  on  column  BS_CREDIT_AGREEMENT_MASTER.MARGIN_PROPORTION   is  '保证金比例';

--更改字段类型
alter table  [表名] alter column [字段名] set data type  [column_type] 
-- decimal(18,4)
--设置字段默认时间为当前时间 
alter table [表名] alter column [字段名] set default  current date; 

-- 去掉字段
alter table [表名] drop column [字段名]

-- 添加表注释
comment on table [表名]  is  '注释内容';

-- 删除外键
alter table AA_ROLEMENU drop constraint FK_REFERENCE_54

-- 备份表数据
create table BD_INFO_CLIENT_BAK as (select c.* from BD_INFO_CLIENT c) definition only;
INSERT INTO BD_INFO_CLIENT_BAK SELECT * FROM BD_INFO_CLIENT;

-- 设置默认值
alter table BD_INFO_CLIENT_BANK alter COLUMN PAYTYPW set default '01';