declare @name varchar(20)select @name=b.name from syscolumns a,sysobjects b where a.id=object_id('tablename') and b.id=a.cdefault and a.name='field1' and b.name like 'DF%'exec('alter table tablename drop constraint '+@name) alter table tablename drop column field1
还是出错 declare @name varchar(20) select @name=b.name from syscolumns a,sysobjects b where a.id=object_id('saldetails') and b.id=a.cdefault and a.name='u6' and b.name like 'DF%' exec('alter table saldetails drop constraint '+@name) 服务器: 消息 3728,级别 16,状态 1,行 1 'DF__saldetails__u6__' 不是约束。 服务器: 消息 3727,级别 16,状态 1,行 1 未能除去约束。请参阅前面的错误信息。
declare @name varchar(1000)select @name=b.name from syscolumns a,sysobjects b where a.id=object_id('tablename') and b.id=a.cdefault and a.name='field1' and b.name like 'DF%'exec('alter table tablename drop constraint '+@name) alter table tablename drop column field1
declare @name varchar(1000) select @name=b.name from syscolumns a,sysobjects b where a.id=object_id('tablename') and b.id=a.cdefault and a.name='field1' and b.name like 'DF%' if @name<>'' begin exec('alter table tablename drop constraint '+@name) end alter table tablename drop column field1
declare @name varchar(20)
select @name=b.name from syscolumns a,sysobjects b where a.id=object_id('saldetails') and b.id=a.cdefault and a.name='u6' and b.name like 'DF%'
exec('alter table saldetails drop constraint '+@name)
服务器: 消息 3728,级别 16,状态 1,行 1
'DF__saldetails__u6__' 不是约束。
服务器: 消息 3727,级别 16,状态 1,行 1
未能除去约束。请参阅前面的错误信息。
DEFAULT 0出错了
服务器: 消息 156,级别 15,状态 1,行 2
在关键字 'DEFAULT' 附近有语法错误。
select @name=b.name from syscolumns a,sysobjects b where a.id=object_id('tablename') and b.id=a.cdefault and a.name='field1' and b.name like 'DF%'
if @name<>''
begin
exec('alter table tablename drop constraint '+@name)
end
alter table tablename drop column field1