半保证没有白痴:

declare @max int;  
select @max = max(key) from table;  
dbcc checkident(table,reseed,@max)

http://sqlserverplanet.com/tsql/using-dbcc-checkident-to-reseed-a-table-after-delete

我知道这是一个老问题。然而，我正在为MySQL寻找类似的解决方案，这个问题出现了。

对于那些正在寻找MySQL解决方案的人，你需要运行这个查询:

// important!!! You cannot reset the counter to a value less than or equal to the value that is currently in use. For both InnoDB and MyISAM, if the value is less than or equal to the maximum value currently in the AUTO_INCREMENT column, the value is reset to the current maximum AUTO_INCREMENT column value plus one.
   
ALTER TABLE <your-table-name> AUTO_INCREMENT = 100

文档

DBCC CHECKIDENT('databasename.dbo.tablename', RESEED, number)

如果number = 0，那么在下一次插入时，自动递增字段将包含值1

如果number = 101，那么在下一次插入时，自动递增字段将包含值102

一些额外的信息…可能对你有用 在上述查询中给出自动递增数之前，必须确保现有表的自动递增列包含的值小于该数。

要从表(table1)中获取列(column_name)的最大值，可以使用以下查询

 SELECT MAX(column_name) FROM table1

You do not want to do this in general. Reseed can create data integrity problems. It is really only for use on development systems where you are wiping out all test data and starting over. It should not be used on a production system in case all related records have not been deleted (not every table that should be in a foreign key relationship is!). You can create a mess doing this and especially if you mean to do it on a regular basis after every delete. It is a bad idea to worry about gaps in you identity field values.

这个呢?

ALTER TABLE `table_name`
  MODIFY `id` int(12) NOT NULL AUTO_INCREMENT, AUTO_INCREMENT=0;

这是一种快速而简单的方法，可以将自动增量更改为0或任何您想要的数字。我通过导出数据库并自己阅读代码来解决这个问题。

你也可以这样写，使它成为一个单行解决方案:

ALTER TABLE `table_name` MODIFY `id` int(12) NOT NULL AUTO_INCREMENT, AUTO_INCREMENT=0;

重置数据库中的每个键，从最后一个最高键的最大值开始自动递增:

Exec sp_MSforeachtable 'DBCC CHECKIDENT(''?'', RESEED, 0)'

Exec sp_MSforeachtable 'DBCC CHECKIDENT(''?'', RESEED)'