用T-SQL语句查找一个数据库里的所有表里的类型为smalldatetime的字段修成datetime的sql语句

declare @tablename sysname
declare @colname sysname
declare @sqlstr varchar(8000)
declare cur cursor for
select a.name,b.name from sysobjects a,syscolumns b
where a.id=b.id and b.xtype=58 and a.xtype='u'
open cur
fetch next from cur
into @tablename,@colname
while @@fetch_status=0
begin
set @sqlstr='alter table ['+@tablename+'] alter column ['+@colname+'] datetime'
exec(@sqlstr)
fetch next from cur
into @tablename,@colname
end
deallocate cur

在相应数据库上下文执行。