變更 欄位 Default 值

1.先取得 Constraint Name
select * from sysobjects o
inner join syscolumns c
on o.id = c.cdefault
inner join sysobjects t
on c.id = t.id
where o.xtype = 'D'
and c.name = 'DrugLn2Amt'
and t.name = 'EF_GDP_Recipehead'

2.刪除 Constraint
Alter Table EF_GDP_RecipeHead Drop DF__EF_GDP_Re__DrugL__21731E62

3.再 Create Constraint
Alter Table EF_GDP_RecipeHead Add   CONSTRAINT [ DF__EF_GDP_Re__DrugL__21731E62] DEFAULT (0) FOR [DrugLn2Amt]