我有SQL Server数据库,我想改变标识列,因为它开始了 有一个大数字10010,它与另一个表相关,现在我有200条记录,我想在记录增加之前修复这个问题。

更改或重置该列的最佳方法是什么?


当前回答

就我所见,有几种方法可以做到这一点。,但在我看来最好和最快的方法是以下一种:

标识列有一个计数器,它不一定与已注册的列相同,您可以使用以下SQL命令查看该计数器的值:

DBCC CHECKIDENT('tableName', NORESEED);

然后,如果你想编辑标识列,你将不能,但我建议在重新播种计数器到你需要的数字后,做一个新的寄存器。要重新播种计数器,使用以下命令:

DBCC CHECKIDENT('tableName', RESEED, desiredNumber);

其他回答

我有类似的问题,我需要更新一些id,我所做的是(我需要增加他们10k):

set identity_insert YourTable ON

INSERT INTO YourTable 
   ([ID]
   ,[something1]
   ,[something2]
   ,[something3])
SELECT 
   ([ID] + 10000)
   ,[something1]
   ,[something2]
   ,[something3]) 
FROM YourTable
WHERE something1 = 'needs updeted id' 
   AND something2 = 'some other condition'

set identity_insert YourTable OFF

DELETE FROM YourTable 
WHERE ID >= 'your old ID From' 
   AND ID <= 'Your old ID To' 

就是这样。希望你能理解这个逻辑,在我的情况下,还有PK-FK键与其他表连接,这意味着我必须更新它们,在我可以从“YourTable”原始行删除之前。

我知道这个问题已经有答案了,我只是想以SQL查询为例,

--before running this make sure Foreign key constraints have been removed that reference the ID. 

--set table to allow identity to be inserted
SET IDENTITY_INSERT yourTable ON;
GO
--insert everything into a temp table
SELECT * 
INTO #tmpYourTable
FROM yourTable

--clear your table
DELETE FROM yourTable
--insert back all the values with the updated ID column
INSERT INTO yourTable (IDCol, OtherCols)
SELECT ID+1 as updatedID --put any other update logic to the ID here
, OtherCols FROM #tmpYourTable
--drop the temp table
DROP TABLE #tmpYourTable
--put identity back to normal
SET IDENTITY_INSERT yourTable OFF;
GO

尝试使用DBCC CHECKIDENT:

DBCC CHECKIDENT ('YourTable', RESEED, 1);
SET IDENTITY_INSERT dbo.TableName ON
INSERT INTO dbo.TableName 
(
    TableId, ColumnName1, ColumnName2, ColumnName3
)
VALUES
(
    TableId_Value, ColumnName1_Value, ColumnName2_Value, ColumnName3_Value
)

SET IDENTITY_INSERT dbo.TableName OFF

当使用Identity_Insert时,不要忘记包含列名,因为sql不允许你在没有指定列名的情况下进行插入

您不能更新标识列。 SQL Server不允许更新标识列,这与使用更新语句更新其他列不同。

尽管有一些替代方案可以实现类似的需求。

当需要为新记录更新标识列值时

使用DBCC CHECKIDENT检查表的当前标识值,如果需要,则更改标识值。

DBCC CHECKIDENT('tableName', RESEED, NEW_RESEED_VALUE)

当需要更新现有记录的标识列值时

使用IDENTITY_INSERT,它允许显式的值插入到表的标识列中。

SET IDENTITY_INSERT YourTable {ON|OFF}

例子:

-- Set Identity insert on so that value can be inserted into this column
SET IDENTITY_INSERT YourTable ON
GO
-- Insert the record which you want to update with new value in the identity column
INSERT INTO YourTable(IdentityCol, otherCol) VALUES(13,'myValue')
GO
-- Delete the old row of which you have inserted a copy (above) (make sure about FK's)
DELETE FROM YourTable WHERE ID=3
GO
--Now set the idenetity_insert OFF to back to the previous track
SET IDENTITY_INSERT YourTable OFF