DBCC CHECKIDENT (<TableName>, reseed, 0)

这将把当前标识值设置为0。

在插入下一个值时，标识值将增加到1。

在可能的情况下使用TRUNCATE总是比删除所有记录更好，因为它也不使用日志空间。

如果我们需要删除和重置种子，请记住，如果表从未被填充，并且您使用DBCC CHECKIDENT('tablenem'，RESEED,0) 那么第一条记录将得到identity = 0 如MSDN文档所述

在您的情况下，只重建索引，而不用担心丢失 级数恒等式这样的情况很常见。

虽然大多数答案都建议RESEED为0，而且有些人认为这是TRUNCATED表的缺陷，但微软有一个排除ID的解决方案

DBCC CHECKIDENT ('[TestTable]', RESEED)

这将检查表并重置到下一个ID。它从MS SQL 2005到现在都是可用的。

https://msdn.microsoft.com/en-us/library/ms176057.aspx

第一个:标识规范只是:“No”>>保存数据库执行项目

之后:身份规范只是:“是”>>保存数据库执行项目

您的数据库ID, PK从1 >>开始

需要注意的是，如果所有的数据都是通过DELETE从表中删除的(即没有WHERE子句)，那么只要a)权限允许，b)没有fk引用表(这里似乎就是这种情况)，使用TRUNCATE table将是首选，因为它可以更有效地DELETE并同时重置IDENTITY种子。以下细节取自TRUNCATE TABLE的MSDN页面:

Compared to the DELETE statement, TRUNCATE TABLE has the following advantages: Less transaction log space is used. The DELETE statement removes rows one at a time and records an entry in the transaction log for each deleted row. TRUNCATE TABLE removes the data by deallocating the data pages used to store the table data and records only the page deallocations in the transaction log. Fewer locks are typically used. When the DELETE statement is executed using a row lock, each row in the table is locked for deletion. TRUNCATE TABLE always locks the table (including a schema (SCH-M) lock) and page but not each row. Without exception, zero pages are left in the table. After a DELETE statement is executed, the table can still contain empty pages. For example, empty pages in a heap cannot be deallocated without at least an exclusive (LCK_M_X) table lock. If the delete operation does not use a table lock, the table (heap) will contain many empty pages. For indexes, the delete operation can leave empty pages behind, although these pages will be deallocated quickly by a background cleanup process. If the table contains an identity column, the counter for that column is reset to the seed value defined for the column. If no seed was defined, the default value 1 is used. To retain the identity counter, use DELETE instead.

下面是:

DELETE FROM [MyTable];
DBCC CHECKIDENT ('[MyTable]', RESEED, 0);

变成:

TRUNCATE TABLE [MyTable];

请参阅TRUNCATE TABLE文档(上面有链接)以获得有关限制等的其他信息。

运行此脚本重置标识列。您需要做两个更改。用需要更新的表替换tableXYZ。此外，标识列的名称需要从临时表中删除。这在一个有35000行和3列的表上是瞬时的。显然，备份表并首先在测试环境中尝试这一点。

select * 
into #temp
From tableXYZ

set identity_insert tableXYZ ON

truncate table tableXYZ

alter table #temp drop column (nameOfIdentityColumn)

set identity_insert tableXYZ OFF

insert into tableXYZ
select * from #temp