近来发现数据库过大,空间不足,因此打算将数据库的数据进行全面的清理,但表非常多,一张一张的清空,实在麻烦,因此就想利用SQL语句一次清空所有数据.找到了三种方法进行清空.使用的数据库为MS SQL SERVER.
1.搜索出所有表名,构造为一条SQL语句
declare
@trun_name
varchar
(
8000
)
set @trun_name = ''
select @trun_name = @trun_name + ' truncate table ' + [ name ] + ' ' from sysobjects where xtype = ' U ' and status > 0
exec ( @trun_name )
set @trun_name = ''
select @trun_name = @trun_name + ' truncate table ' + [ name ] + ' ' from sysobjects where xtype = ' U ' and status > 0
exec ( @trun_name )
该方法适合表不是非常多的情况,否则表数量过多,超过字符串的长度,不能进行完全清理.
2.利用游标清理所有表
declare
@trun_name
varchar
(
50
)
declare name_cursor cursor for
select ' truncate table ' + name from sysobjects where xtype = ' U ' and status > 0
open name_cursor
fetch next from name_cursor into @trun_name
while @@FETCH_STATUS = 0
begin
exec ( @trun_name )
print ' truncated table ' + @trun_name
fetch next from name_cursor into @trun_name
end
close name_cursor
deallocate name_cursor
declare name_cursor cursor for
select ' truncate table ' + name from sysobjects where xtype = ' U ' and status > 0
open name_cursor
fetch next from name_cursor into @trun_name
while @@FETCH_STATUS = 0
begin
exec ( @trun_name )
print ' truncated table ' + @trun_name
fetch next from name_cursor into @trun_name
end
close name_cursor
deallocate name_cursor
这是我自己构造的,可以做为存储过程调用, 能够一次清空所有表的数据,并且还可以进行有选择的清空表.
3.利用微软未公开的存储过程
exec
sp_msforeachtable "
truncate
table
?"
该方法可以一次清空所有表,但不能加过滤条件.