我从SQL Server数据库的一个表中删除了一些记录。

表中的id是这样的:

99 100 101 1200 1201...

我想删除后来的记录(ID >1200),然后我想重置自动增量,以便下一个自动生成的ID将是102。所以我的记录是顺序的,有办法做到这一点在SQL Server?


当前回答

如果你正在使用MySQL,试试这个:

ALTER TABLE tablename AUTO_INCREMENT = 1

其他回答

我想添加这个答案是因为DBCC checkident -方法在对表使用模式时会产生问题。用这个来确定:

DECLARE @Table AS NVARCHAR(500) = 'myschema.mytable';
DBCC CHECKIDENT (@Table, RESEED, 0);

如果需要检查操作是否成功,请使用

SELECT IDENT_CURRENT(@Table);

在上面的例子中应该输出0。

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;

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.

我想明白了。它是:

 DBCC CHECKIDENT ('tablename', RESEED, newseed)

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

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