SQL 重新播种有效，但自动增量从 0 开始

Question

我有一些表有一个身份列，我正在尝试重新设定。重新播种有效(我认为)但是当一个新数据项插入到表中时，标识列从 0 开始。

我要重新播种的代码是:

DBCC CHECKIDENT(MyTable, RESEED, 0)

表的身份规范是:

身份增量 = 1

身份种子 = 1

快速说明 我在重新播种之前对表执行删除操作

请帮忙

Answer 1

当种子被初始化为 0 时，“未初始化”或截断的表(意味着没有数据被插入到表中)似乎将从 0 开始。但是当数据被插入到表中并且使用删除来清除所有表的行。重新播种为 0 只会使数据库的最后一个种子为 0，而下一个种子为 1。

也就是说，这里是一个复制问题的例子:

-- Script to create a test table
IF EXISTS(SELECT 1 FROM Information_Schema.Tables WHERE TABLE_SCHEMA = 'dbo' 
            AND TABLE_NAME = 'SeedTest') BEGIN

    DROP TABLE SeedTest

END

-- Create a Test Seed Table
CREATE TABLE [dbo].[SeedTest](
    [Id] [int] IDENTITY(1,1) NOT NULL,
    [Value] [varchar](255) NOT NULL,
 CONSTRAINT [PK_SeedTest] PRIMARY KEY CLUSTERED 
(
    [Id] ASC
) WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

GO


-- When a table is truncated or "Not Initialized" (meaning no data EVER inserted)
-- An initial reseed of 0 will make the first identity insert value = 0.
DBCC CHECKIDENT (SeedTest, RESEED, 0)

GO

INSERT INTO SeedTest([Value]) VALUES('Test')
SELECT * FROM SeedTest

GO

-- If you truncate the table and reseed the same effect will occur (first identity insert value = 0).
TRUNCATE TABLE SeedTest

GO

DBCC CHECKIDENT (SeedTest, RESEED, 0)

GO

INSERT INTO SeedTest([Value]) VALUES('Test')

SELECT * FROM SeedTest


-- When Deleting records from a table (Foreign key constraints may prevent a truncate)
-- Reseeding to 0 will set the last seed to 0 and make the next seed = 1
DELETE FROM SeedTest

GO

DBCC CHECKIDENT (SeedTest, RESEED, 0)

GO

INSERT INTO SeedTest([Value]) VALUES('Test')
SELECT * FROM SeedTest

GO