SQL Server删除表

Question

如果您在SQL Server中删除一个有键、索引、约束等的表，它会将这些也一并删除吗？我只是想知道当我编写脚本时是否需要为所有这些创建删除脚本，还是只需删除表格即可？

谢谢，

S

- scarpacci

Answer 1

是的，虽然你不能删除被其他表外键引用的表。

以下是在SQL Server 2008中删除引用它的外键的表的步骤：

create table TA ( AID int identity(1, 1), OtherId int, Name varchar(512), constraint PK_TA primary key (AID))
create table TB ( BID int identity(1, 1), OtherId int, Name varchar(512), constraint PK_TB primary key (BID))
alter table TA add constraint FK_TA_TB foreign key (OtherId) references TB (BID)
alter table TB add constraint FK_TB_TA foreign key (OtherId) references TA (AID)

drop table ta -- doesn't work
drop table tb -- doesn't work

create procedure my_DropTable @tableName varchar(512) as
begin
    if OBJECT_ID(@tableName) is null begin print 'OBJECT DOES NOT EXIST' return end
    declare @sql nvarchar(max)
    while exists (select * from sys.foreign_keys where referenced_object_id = object_id(@tableName))
    begin
        select @sql = 'ALTER TABLE ' + OBJECT_NAME(parent_object_id) + ' DROP CONSTRAINT ' + OBJECT_NAME(object_id)
        from sys.foreign_keys where referenced_object_id = object_id(@tableName)

        exec sp_executesql @sql
    end
    set @sql = 'DROP TABLE ' + @tableName
    exec sp_executesql @sql
end

exec my_DropTable 'TA'
exec my_DropTable 'TB'

- Jason Goemaat

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确实，如果您正在编写一个脚本来删除所有内容，那么您需要以这样的方式来执行它，即首先删除引用其他表的表。 - bjorsig

@bjorsig：除非您有循环引用，但在我的经验中这种情况并不常见。 - Shannon Severance