要删除某个数据库，或者删除数据库中的所有表（删除表结构和数据），需要先删除表间的外键约束，才能删除表。如删除数据库db_wy中的所有表：
--/第1步**********删除所有表的外键约束*************************/DECLARE c1 cursor forselect 'alter table ['+ object_name(parent_obj) + '] drop constraint ['+name+']; 'from sysobjectswhere xtype = 'F'open c1declare @c1 varchar(8000)fetch next from c1 into @c1while(@@fetch_status=0)beginexec(@c1)fetch next from c1 into @c1endclose c1deallocate c1--/第2步**********删除所有表*************************/use db_wyGOdeclare @sql varchar(8000)while (select count(*) from sysobjects where type='U')>0beginSELECT @sql='drop table ' + nameFROM sysobjectsWHERE (type = 'U')ORDER BY 'drop table ' + nameexec(@sql) end