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?
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
我已经解决了这个问题,首先使用DBCC,然后使用插入。例如,如果你的桌子是
首先在表中设置新的当前ID Value为NEW_RESEED_VALUE
MyTable { IDCol, 可乐, colB }
DBCC CHECKIDENT('MyTable', RESEED, NEW_RESEED_VALUE)
然后你可以使用
insert into MyTable (colA, ColB) select colA, colB from MyTable
这将复制所有记录,但使用新的IDCol值作为NEW_RESEED_VALUE开始。然后,在删除/移动外键引用(如果有)后,可以删除ID值较高的重复行。
其他回答
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
尝试使用DBCC CHECKIDENT:
DBCC CHECKIDENT ('YourTable', RESEED, 1);
你需要
set identity_insert YourTable ON
然后删除行并重新插入不同的标识。
插入完成后,不要忘记关闭identity_insert
set identity_insert YourTable OFF
将您的表复制到没有标识列的新表。
select columns into newtable from yourtable
用new seed添加一个标识列到newtable,并将其作为主键
ALTER TABLE tableName ADD id MEDIUMINT NOT NULL AUTO_INCREMENT KEY
我做了以下事情:
将相关数据移动到临时存储中 更新主键/标识列值(删除和创建约束) 用新的外键值重新插入相关数据
我把我的解决方案包装在一个存储过程中:
CREATE PROCEDURE [dbo].[UpdateCustomerLocationId]
@oldCustomerLocationId INT,
@newCustomerLocationId INT
AS
/*
Updates CustomerLocation.CustomerLocationId @oldCustomerLocationId to @newCustomerLocationId
Example:
EXEC [dbo].[UpdateCustomerLocationId]
@oldCustomerLocationId = 6154874,
@newCustomerLocationId = 50334;
*/
BEGIN
SET NOCOUNT ON;
-- exit if @oldCustomerLocationId does not exists
IF NOT EXISTS (SELECT * FROM dbo.CustomerLocation cl WHERE cl.CustomerLocationId = @oldCustomerLocationId)
BEGIN
PRINT CONCAT('CustomerLocationId ''', @oldCustomerLocationId, ''' (@oldCustomerLocationId) does not exist in dbo.CustomerLocation');
RETURN 1; -- 0 = success, > 0 = failure
END
-- exit if @newCustomerLocationId already exists
IF EXISTS (SELECT * FROM dbo.CustomerLocation cl WHERE cl.CustomerLocationId = @newCustomerLocationId)
BEGIN
PRINT CONCAT('CustomerLocationId ''', @newCustomerLocationId, ''' (@newCustomerLocationId) already exists in dbo.CustomerLocation');
RETURN 2; -- 0 = success, > 0 = failure
END
BEGIN TRAN;
BEGIN -- MOVE related data into temporary storage
IF EXISTS (SELECT * FROM dbo.CustomerLocationData t WHERE t.CustomerLocationId = @oldCustomerLocationId) BEGIN
IF OBJECT_ID('tempdb..#CustomerLocationData') IS NOT NULL
DROP TABLE #CustomerLocationData;
SELECT * INTO #CustomerLocationData FROM dbo.CustomerLocationData t WHERE t.CustomerLocationId = @oldCustomerLocationId;
DELETE t FROM dbo.CustomerLocationData t WHERE t.CustomerLocationId = @oldCustomerLocationId;
END
END
BEGIN -- UPDATE dbo.CustomerLocation
-- DROP CONSTRAINTs
ALTER TABLE [dbo].[CustomerLocation] DROP CONSTRAINT [UC_CustomerLocation];
-- INSERT OLD record with new CustomerLocationId
SET IDENTITY_INSERT dbo.CustomerLocation ON;
INSERT INTO dbo.CustomerLocation
(
CustomerLocationId, CustomerId, LocationId, CustomerLocationIdent, CustomerLocationIdent2, LocationIdent, LocationName, CustomerDistrictId,
CustomerLocationGUID, UpdatedOn, IssueManager, EnrollSelfMonitoring, TemperatureControlDeadlineHour, CreatedOn, OperationBegin, ActiveCustomer,
Comments, LocationName2, ParentGroup, TempString1, TempString2, TempString3, TempString4, TempString5, AutoInheritFromLocation, ClassificationPrimary
)
SELECT @newCustomerLocationId AS CustomerLocationId, CustomerId,LocationId, CustomerLocationIdent, CustomerLocationIdent2, LocationIdent, LocationName, CustomerDistrictId,
CustomerLocationGUID, UpdatedOn, IssueManager, EnrollSelfMonitoring, TemperatureControlDeadlineHour, CreatedOn, OperationBegin, ActiveCustomer,
Comments,LocationName2, ParentGroup, TempString1, TempString2, TempString3, TempString4, TempString5, AutoInheritFromLocation, ClassificationPrimary
FROM dbo.CustomerLocation
WHERE CustomerLocationId = @oldCustomerLocationId;
SET IDENTITY_INSERT dbo.CustomerLocation OFF;
-- DELETE OLD record
DELETE cl FROM dbo.CustomerLocation cl WHERE cl.CustomerLocationId = @oldCustomerLocationId;
-- ADD CONSTRAINTS
ALTER TABLE [dbo].[CustomerLocation] ADD CONSTRAINT [UC_CustomerLocation] UNIQUE NONCLUSTERED ([CustomerId], [LocationId]);
END
BEGIN -- re-INSERT related data from temporary storage
IF OBJECT_ID('tempdb..#CustomerLocationData') IS NOT NULL BEGIN
SET IDENTITY_INSERT dbo.CustomerLocationData ON;
INSERT INTO dbo.CustomerLocationData (Guid, CustomerLocationId, CustomerLocationDataTypeId, Date, Category, Data)
SELECT Guid, @newCustomerLocationId CustomerLocationId, CustomerLocationDataTypeId, Date, Category, Data FROM #CustomerLocationData;
SET IDENTITY_INSERT dbo.CustomerLocationData OFF;
END
END
COMMIT TRAN;
END