--默认值或 DEFAULT 约束
DECLARE @STRING VARCHAR(8000)
WHILE EXISTS(SELECT NAME FROM SYSOBJECTS WHERE XTYPE='D')
BEGIN
SELECT @STRING='ALTER TABLE '+B.NAME+' DROP CONSTRAINT '+A.NAME+CHAR(13)
FROM (SELECT PARENT_OBJ,NAME FROM SYSOBJECTS WHERE XTYPE='D') A,
(SELECT ID,NAME FROM SYSOBJECTS WHERE OBJECTPROPERTY(ID, N'ISUSERTABLE') = 1) B
WHERE A.PARENT_OBJ=B.ID
EXEC(@STRING)
END
GO
--UNIQUE 约束
DECLARE @STRING VARCHAR(8000)
WHILE EXISTS(SELECT NAME FROM SYSOBJECTS WHERE XTYPE='UQ')
BEGIN
SELECT @STRING='ALTER TABLE '+B.NAME+' DROP CONSTRAINT '+A.NAME+CHAR(13)
FROM (SELECT PARENT_OBJ,NAME FROM SYSOBJECTS WHERE XTYPE='UQ') A,
(SELECT ID,NAME FROM SYSOBJECTS WHERE OBJECTPROPERTY(ID, N'ISUSERTABLE') = 1) B
WHERE A.PARENT_OBJ=B.ID
EXEC(@STRING)
END
GO
--FOREIGN KEY 约束
DECLARE @STRING VARCHAR(8000)
WHILE EXISTS(SELECT NAME FROM SYSOBJECTS WHERE TYPE='F')
BEGIN
SELECT @STRING='ALTER TABLE '+B.NAME+' DROP CONSTRAINT '+A.NAME+CHAR(13)
FROM (SELECT PARENT_OBJ,NAME FROM SYSOBJECTS WHERE TYPE='F') A,
(SELECT ID,NAME FROM SYSOBJECTS WHERE OBJECTPROPERTY(ID, N'ISUSERTABLE') = 1) B
WHERE A.PARENT_OBJ=B.ID
EXEC(@STRING)
END
--declare tb cursor local for
--默认值约束
select sql='alter table ['+b.name+'] drop constraint ['+d.name+']'
from syscolumns a
join sysobjects b on a.id=b.id
join syscomments c on a.cdefault=c.id
join sysobjects d on c.id=d.id
where b.name=@tbname
and a.name=@fdname
union all --外键引用
select s='alter table ['+c.name+'] drop constraint ['+b.name+']'
from sysforeignkeys a
join sysobjects b on b.id=a.constid
join sysobjects c on c.id=a.fkeyid
join syscolumns d on d.id=c.id and a.fkey=d.colid
join sysobjects e on e.id=a.rkeyid
join syscolumns f on f.id=e.id and a.rkey=f.colid
where e.name=@tbname
and d.name=@fdname
union all --索引
select case e.xtype when 'PK' then 'alter table ['+c.name+'] drop constraint ['+e.name+']'
else 'drop index ['+c.name+'].['+a.name+']' end
from sysindexes a
join sysindexkeys b on a.id=b.id and a.indid=b.indid
join sysobjects c on b.id=c.id and c.xtype='U' and c.name<>'dtproperties'
join syscolumns d on b.id=d.id and b.colid=d.colid
join sysobjects e on c.id=e.parent_obj
where a.indid not in(0,255)
and c.name=@tbname
and d.name=@fdname
declare @s varchar(8000)
open tb
fetch next from tb into @s
while @@fetch_status=0
begin
exec(@s)
fetch next from tb into @s
end
close tb
deallocate tb