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

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

其他回答

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
ALTER TABLE tablename add newcolumn int
update tablename set newcolumn=existingcolumnname
ALTER TABLE tablename DROP COLUMN existingcolumnname;
EXEC sp_RENAME 'tablename.oldcolumn' , 'newcolumnname', 'COLUMN'
update tablename set newcolumnname=value where condition

然而,上面的代码只有在没有主-外键关系的情况下才能工作

尝试使用DBCC CHECKIDENT:

DBCC CHECKIDENT ('YourTable', RESEED, 1);
--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

如果您特别需要将主键值更改为不同的数字(例如123 -> 1123)。identity属性阻止更改PK值。Set Identity_insert将不起作用。如果您有级联删除,则不建议执行插入/删除操作(除非您关闭了引用完整性检查)。

编辑:新版本的SQL不允许更改syscolumns实体,因此我的部分解决方案必须以艰难的方式完成。关于如何从主键中删除Identity,请参考这个SO: 从表中的列中删除Identity 这个脚本将在PK中关闭标识:

***********************

sp_configure 'allow update', 1
go
reconfigure with override
go


update syscolumns set colstat = 0 --turn off bit 1 which indicates identity column
where id = object_id('table_name') and name = 'column_name'
go


exec sp_configure 'allow update', 0
go
reconfigure with override
go

***********************

接下来,您可以设置关系,以便它们更新外键引用。否则你需要关闭关系强制执行。这个SO链接展示了如何: 如何使用T-SQL临时禁用外键约束?

现在,您可以进行更新。我写了一个简短的脚本来基于相同的列名编写所有的更新SQL(在我的情况下,我需要将CaseID增加1,000,000:

select 
'update ['+c.table_name+'] SET ['+Column_Name+']=['+Column_Name+']+1000000'
from Information_Schema.Columns as c
JOIN Information_Schema.Tables as t ON t.table_Name=c.table_name and t.Table_Schema=c.table_schema and t.table_type='BASE TABLE'
where Column_Name like 'CaseID' order by Ordinal_position

最后,重新启用引用完整性,然后重新启用主键上的Identity列。

注意:我看到有些人在这些问题上问为什么。在我的例子中,我必须将来自第二个生产实例的数据合并到主DB中,这样才能关闭第二个实例。我只需要所有操作数据的PK/ fk不发生冲突。元数据fk是相同的。