我们有 JCC 将数据从 Oracle 提供给 SQL Server 2016。由于某些未知原因，历史表中存在具有相同开始和结束时间的重复项。怎么会发生？我尝试使用条件 SET Column = Column 更新记录。在那种情况下，我有 2 条记录，其中所有字段都相同，但开始时间和结束时间不同。怎么会出现相同的日期时间呢？
更新:
数据链接:
CREATE TABLE [dbo].[LEASES](
[LEASE_NUMBER] [CHAR](7) NOT NULL,
[CREDIT_DECISION_CODE] [CHAR](1) NULL,
[LEASE_APPLICATION] [CHAR](7) NULL,
[ACCOUNT_NUMBER] [CHAR](8) NULL,
[CELLULAR_NUMBER] [CHAR](10) NULL,
[DEALER_CODE] [CHAR](5) NULL,
[USERNAME] [CHAR](12) NULL,
[LEASE_DATE] [DATETIME2](7) NULL,
[NEW_USED_FLAG] [CHAR](1) NULL,
[MANUFACTURER_CODE] [CHAR](6) NULL,
[MODEL] [CHAR](10) NULL,
[SERIAL_NUMBER_ELECTRONIC] [INT] NULL,
[SERIAL_NUMBER_MECHANICAL] [CHAR](10) NULL,
[CONTROL_HEAD] [CHAR](12) NULL,
[LEASE_TERM] [SMALLINT] NULL,
[LESSEE_CITY] [CHAR](17) NULL,
[LESSEE_ADDRESS_1] [CHAR](30) NULL,
[LESSEE_ADDRESS_2] [CHAR](30) NULL,
[LESSEE_STATE] [CHAR](2) NULL,
[LESSEE_ZIP_CODE] [CHAR](9) NULL,
[LESSEE_NAME] [CHAR](30) NULL,
[KEY_NAME] [CHAR](12) NULL,
[BASE_PAYMENT] [DECIMAL](10, 2) NULL,
[MONTHLY_SALES_TAX] [DECIMAL](10, 2) NULL,
[INSURANCE] [DECIMAL](10, 2) NULL,
[MONTHLY_PAYMENT] [DECIMAL](10, 2) NULL,
[SECURITY_DEPOSIT] [DECIMAL](10, 2) NULL,
[INVOICES_GENERATED_COUNT] [SMALLINT] NULL,
[DATE_LAST_INVOICED] [DATETIME] NULL,
[DATE_LAST_LATE_FEE] [DATETIME] NULL,
[SECURITY_DEPOSITS_INVOICED] [DECIMAL](10, 2) NULL,
[SECURITY_DEPOSITS_REFUNDED] [DECIMAL](10, 2) NULL,
[ADVANCE_RENT] [DECIMAL](10, 2) NULL,
[ADVANCE_SALES_TAX] [DECIMAL](10, 2) NULL,
[TOTAL_ADVANCE_PAYMENT] [DECIMAL](10, 2) NULL,
[AUTO_LEASE_EXPIRATION_DATE] [CHAR](4) NULL,
[PAYMENTS_REMAINING] [SMALLINT] NULL,
[PV_PAYMENTS_REMAINING] [DECIMAL](10, 2) NULL,
[TAX_RATE] [DECIMAL](10, 4) NULL,
[TAX_STATE] [CHAR](2) NULL,
[LEASE_FACTOR] [DECIMAL](10, 4) NULL,
[AMOUNT_FINANCED] [DECIMAL](10, 2) NULL,
[REMARKS] [CHAR](60) NULL,
[VOUCHER_NUMBER] [CHAR](12) NULL,
[BILL_METHOD_ADVANCE] [CHAR](1) NULL,
[FINANCING_PACKAGE] [INT] NULL,
[BUYOUT_AMOUNT] [DECIMAL](10, 2) NULL,
[BUYOUT_DATE] [DATETIME] NULL,
[DEPRECIATION_MONTHS] [SMALLINT] NULL,
[SALVAGE_VALUE] [DECIMAL](10, 2) NULL,
[LAST_DEPRECIATION_DATE] [DATETIME] NULL,
[LAST_DEPRECIATION_AMOUNT] [DECIMAL](10, 2) NULL,
[ACCUMULATED_DEPRECIATION] [DECIMAL](10, 2) NULL,
[BILL_METHOD_BUYOUT] [CHAR](1) NULL,
[BUYOUT_INVOICED] [CHAR](1) NULL,
[RECEIVED_DATE] [DATETIME] NULL,
[LEASE_PROGRAM] [CHAR](5) NULL,
[PAYMENTS_INCLUDED_ADVANCE] [SMALLINT] NULL,
[SALESPERSON_CODE] [CHAR](5) NULL,
[UNGUARANTEED_RESIDUAL_VALUE] [DECIMAL](10, 2) NULL,
[UNEARNED_INCOME] [DECIMAL](10, 2) NULL,
[DIRECT_COST] [DECIMAL](10, 2) NULL,
[AMORTIZABLE_UNEARNED_INCOME] [DECIMAL](10, 2) NULL,
[AMORTIZED_FLAG] [CHAR](1) NULL,
[RESIDUAL_VALUE_PERCENTAGE] [DECIMAL](10, 4) NULL,
[MINIMUM_LEASE_PAYMENTS] [DECIMAL](10, 2) NULL,
[IMPLICIT_MONTHLY_INTEREST_RATE] [DECIMAL](10, 8) NULL,
[AP_POSTED_FLAG] [CHAR](1) NULL,
[AP_POSTED_DATE] [DATETIME] NULL,
[CAPITALIZED_LEASE_FLAG] [CHAR](1) NULL,
[LEASE_STATUS] [CHAR](1) NULL,
[GROSS_INVESTMENT] [DECIMAL](10, 2) NULL,
[ADVANCE_BILLED_FLAG] [CHAR](1) NULL,
[AP_VOUCHER_NUMBER] [CHAR](12) NULL,
[BANK_PACKAGE] [CHAR](5) NULL,
[INSURANCE_BINDER] [CHAR](1) NULL,
[CURRENT_BUYOUT] [DECIMAL](10, 2) NULL,
[LEASE_AGE_YEARS] [SMALLINT] NULL,
[GUARANTOR_NAME] [CHAR](30) NULL,
[GUARANTOR_ADDRESS_LINE_1] [CHAR](30) NULL,
[GUARANTOR_ADDRESS_LINE_2] [CHAR](30) NULL,
[GUARANTOR_CITY] [CHAR](17) NULL,
[GUARANTOR_STATE] [CHAR](2) NULL,
[GUARANTOR_ZIP] [CHAR](9) NULL,
[GUARANTOR_TELEPHONE] [CHAR](18) NULL,
[GUARANTOR_SS_NUMBER] [CHAR](9) NULL,
[GUARANTOR] [CHAR](30) NULL,
[BILL_CYCLES_DEFER] [INT] NULL,
[REVENUE_ACCOUNT] [CHAR](5) NULL,
[INVOICE_TYPE] [CHAR](5) NULL,
[CORRESPONDENCE_FLAG] [CHAR](1) NULL,
[DOWN_PAYMENT] [DECIMAL](10, 2) NULL,
[ADVANCE_INSURANCE] [DECIMAL](10, 2) NULL,
[ORIGINAL_EQUIPMENT_COST] [DECIMAL](10, 2) NULL,
[SERVICING_DEALER_CODE] [CHAR](5) NULL,
[DEALER_BUYOUT_DATE] [DATETIME] NULL,
[LEASE_OWNER_CODE] [CHAR](5) NULL,
[LEASE_OWNER_DATE] [DATETIME] NULL,
[VENDOR_CODE] [CHAR](5) NULL,
[SPLIT_FUNDING_COUNT] [SMALLINT] NULL,
[DEALER_AMOUNT] [DECIMAL](10, 2) NULL,
[VENDOR_AMOUNT] [DECIMAL](10, 2) NULL,
[SALESPERSON_AMOUNT] [DECIMAL](10, 2) NULL,
[DEALER_OFFICE] [SMALLINT] NULL,
[ASSESSMENT_YEAR] [SMALLINT] NULL,
[PROPERTY_TAX_RATE] [DECIMAL](10, 4) NULL,
[ASSESSMENT_FACTOR] [DECIMAL](10, 4) NULL,
[MONTHLY_PROPERTY_TAX] [DECIMAL](10, 2) NULL,
[MANAGER_CODE] [CHAR](5) NULL,
[DEALER_BUYOUT_PROGRAM] [CHAR](5) NULL,
[SHARED_RESID_METHOD] [CHAR](1) NULL,
[SHARED_RESID_AMOUNT] [DECIMAL](10, 2) NULL,
[SHARED_RESID_PERCENT] [DECIMAL](10, 4) NULL,
[SHARED_RESID_L_AND_D] [CHAR](1) NULL,
[SHARED_RESID_COLLECTION_TYPE] [CHAR](1) NULL,
[SHARED_RESID_MONTHS_OVERDUE] [SMALLINT] NULL,
[ORIGINAL_LEASE_TERM] [SMALLINT] NULL,
[ORIGINAL_LEASE_DATE] [DATETIME] NULL,
[ORIGINAL_BASE_PAYMENT] [DECIMAL](10, 2) NULL,
[ORIGINAL_MINIMUM_PAYMENTS] [DECIMAL](10, 2) NULL,
[NEW_PAYMENT_PLAN_FLAG] [CHAR](1) NULL,
[NEW_PAYMENT_PLAN_OFFSET] [SMALLINT] NULL,
[NEW_PAYMENT_PLAN_DATE] [DATETIME] NULL,
[NEW_MINIMUM_PAYMENTS] [DECIMAL](10, 2) NULL,
[BILLING_PERIOD_NUMBER] [SMALLINT] NULL,
[BILLING_PERIOD_1_INVOICES] [SMALLINT] NULL,
[BILLING_PERIOD_1_PAYMENT] [DECIMAL](10, 2) NULL,
[BILLING_PERIOD_2_INVOICES] [SMALLINT] NULL,
[BILLING_PERIOD_2_PAYMENT] [DECIMAL](10, 2) NULL,
[BILLING_PERIOD_3_INVOICES] [SMALLINT] NULL,
[BILLING_PERIOD_3_PAYMENT] [DECIMAL](10, 2) NULL,
[BILLING_PERIOD_4_INVOICES] [SMALLINT] NULL,
[BILLING_PERIOD_4_PAYMENT] [DECIMAL](10, 2) NULL,
[BILLING_PERIOD_5_INVOICES] [SMALLINT] NULL,
[BILLING_PERIOD_5_PAYMENT] [DECIMAL](10, 2) NULL,
[BILLING_PERIOD_6_INVOICES] [SMALLINT] NULL,
[BILLING_PERIOD_6_PAYMENT] [DECIMAL](10, 2) NULL,
[EQUIPMENT_AMOUNT] [DECIMAL](10, 2) NULL,
[SERVICE_AMOUNT] [DECIMAL](10, 2) NULL,
[MONTHS_OF_RECOURSE] [SMALLINT] NULL,
[VENDOR_PAID_FLAG] [CHAR](1) NULL,
[SALESPERSON_PAID_FLAG] [CHAR](1) NULL,
[AP_ACCOUNT] [CHAR](5) NULL,
[GL_AP_ACCOUNT] [CHAR](4) NULL,
[GL_OWNER_COMPANY] [CHAR](4) NULL,
[GL_BRANCH] [CHAR](1) NULL,
[GL_DEPARTMENT] [CHAR](2) NULL,
[GL_EQUIPMENT] [CHAR](2) NULL,
[GL_STATE] [CHAR](2) NULL,
[DEALER_RECOURSE_PERCENT] [DECIMAL](10, 4) NULL,
[VENDOR_RECOURSE_PERCENT] [DECIMAL](10, 4) NULL,
[SALESPERSON_RECOURSE_PERCENT] [DECIMAL](10, 4) NULL,
[NUMBER_OF_UNITS] [SMALLINT] NULL,
[INVOICES_SUBJECT_TO_DISCOUNT] [CHAR](1) NULL,
[ORIGINAL_LEASE_PROGRAM] [CHAR](5) NULL,
[MISSING_PAYMENT_COUNT] [SMALLINT] NULL,
[BROKER_CODE] [CHAR](5) NULL,
[REVENUE_SHARING_CODE] [CHAR](5) NULL,
[REVENUE_SHARING_FACTOR] [DECIMAL](5, 2) NULL,
[REVENUE_SHARING_FLAG] [CHAR](1) NULL,
[DEALER_SHARING_CODE] [CHAR](5) NULL,
[DEALER_SHARING_FACTOR] [DECIMAL](5, 2) NULL,
[DEALER_SHARING_FLAG] [CHAR](1) NULL,
[CHARGEBACK_RESERVE_FLAG] [CHAR](1) NULL,
[FUNDING_FEE] [DECIMAL](10, 2) NULL,
[FUNDING_FEE_INVOICED_FLAG] [CHAR](1) NULL,
[LEASE_REFERENCE] [CHAR](30) NULL,
[ORIGINAL_LEASE_NUMBER] [CHAR](12) NULL,
[ORIGINAL_ACCOUNT_NUMBER] [CHAR](12) NULL,
[BASE_PAYMENT_TAXABLE] [CHAR](1) NULL,
[DAY_TO_CHARGE_BACK] [SMALLINT] NULL,
[LESSEE_FED_ID_NUMBER] [CHAR](9) NULL,
[ORIGINAL_PURCHASE_PRICE] [DECIMAL](10, 2) NULL,
[ORIGINAL_PURCHASE_DATE] [DATETIME] NULL,
[ACQUISITION_PURCHASE_PRICE] [DECIMAL](10, 2) NULL,
[ACQUISITION_PURCHASE_DATE] [DATETIME] NULL,
[BROKER_REV_SHAR_AMT_OVERRIDE] [DECIMAL](10, 2) NULL,
[DEALER_REV_SHAR_AMT_OVERRIDE] [DECIMAL](10, 2) NULL,
[UPFRONT_TAX_FLAG] [CHAR](1) NULL,
[UPFRONT_TAX_AMOUNT] [DECIMAL](10, 2) NULL,
[UPFRONT_TAX_BILLED] [CHAR](1) NULL,
[SysStart] [DATETIME2](7) GENERATED ALWAYS AS ROW START NOT NULL,
[SysEnd] [DATETIME2](7) GENERATED ALWAYS AS ROW END NOT NULL,
PRIMARY KEY CLUSTERED
(
[LEASE_NUMBER] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY],
PERIOD FOR SYSTEM_TIME ([SysStart], [SysEnd])
) ON [PRIMARY]
WITH
(
SYSTEM_VERSIONING = ON ( HISTORY_TABLE = [dbo].[LEASES_HISTORY] )
)
GO
更新 2:
我无法提供真实数据，但这是我用来获取重复项的查询。请注意，我对表中的所有列进行 GROUPing BY，因此这些列肯定是重复的:
SELECT LEASE_NUMBER
, SysStart
, SysEnd
, cnt
FROM
( SELECT *
, COUNT(*) cnt
FROM dbo.LEASES_HISTORY AS l
GROUP BY l.LEASE_NUMBER
, l.CREDIT_DECISION_CODE
, l.LEASE_APPLICATION
, l.ACCOUNT_NUMBER
, l.CELLULAR_NUMBER
, l.DEALER_CODE
, l.USERNAME
, l.LEASE_DATE
, l.NEW_USED_FLAG
, l.MANUFACTURER_CODE
, l.MODEL
, l.SERIAL_NUMBER_ELECTRONIC
, l.SERIAL_NUMBER_MECHANICAL
, l.CONTROL_HEAD
, l.LEASE_TERM
, l.LESSEE_CITY
, l.LESSEE_ADDRESS_1
, l.LESSEE_ADDRESS_2
, l.LESSEE_STATE
, l.LESSEE_ZIP_CODE
, l.LESSEE_NAME
, l.KEY_NAME
, l.BASE_PAYMENT
, l.MONTHLY_SALES_TAX
, l.INSURANCE
, l.MONTHLY_PAYMENT
, l.SECURITY_DEPOSIT
, l.INVOICES_GENERATED_COUNT
, l.DATE_LAST_INVOICED
, l.DATE_LAST_LATE_FEE
, l.SECURITY_DEPOSITS_INVOICED
, l.SECURITY_DEPOSITS_REFUNDED
, l.ADVANCE_RENT
, l.ADVANCE_SALES_TAX
, l.TOTAL_ADVANCE_PAYMENT
, l.AUTO_LEASE_EXPIRATION_DATE
, l.PAYMENTS_REMAINING
, l.PV_PAYMENTS_REMAINING
, l.TAX_RATE
, l.TAX_STATE
, l.LEASE_FACTOR
, l.AMOUNT_FINANCED
, l.REMARKS
, l.VOUCHER_NUMBER
, l.BILL_METHOD_ADVANCE
, l.FINANCING_PACKAGE
, l.BUYOUT_AMOUNT
, l.BUYOUT_DATE
, l.DEPRECIATION_MONTHS
, l.SALVAGE_VALUE
, l.LAST_DEPRECIATION_DATE
, l.LAST_DEPRECIATION_AMOUNT
, l.ACCUMULATED_DEPRECIATION
, l.BILL_METHOD_BUYOUT
, l.BUYOUT_INVOICED
, l.RECEIVED_DATE
, l.LEASE_PROGRAM
, l.PAYMENTS_INCLUDED_ADVANCE
, l.SALESPERSON_CODE
, l.UNGUARANTEED_RESIDUAL_VALUE
, l.UNEARNED_INCOME
, l.DIRECT_COST
, l.AMORTIZABLE_UNEARNED_INCOME
, l.AMORTIZED_FLAG
, l.RESIDUAL_VALUE_PERCENTAGE
, l.MINIMUM_LEASE_PAYMENTS
, l.IMPLICIT_MONTHLY_INTEREST_RATE
, l.AP_POSTED_FLAG
, l.AP_POSTED_DATE
, l.CAPITALIZED_LEASE_FLAG
, l.LEASE_STATUS
, l.GROSS_INVESTMENT
, l.ADVANCE_BILLED_FLAG
, l.AP_VOUCHER_NUMBER
, l.BANK_PACKAGE
, l.INSURANCE_BINDER
, l.CURRENT_BUYOUT
, l.LEASE_AGE_YEARS
, l.GUARANTOR_NAME
, l.GUARANTOR_ADDRESS_LINE_1
, l.GUARANTOR_ADDRESS_LINE_2
, l.GUARANTOR_CITY
, l.GUARANTOR_STATE
, l.GUARANTOR_ZIP
, l.GUARANTOR_TELEPHONE
, l.GUARANTOR_SS_NUMBER
, l.GUARANTOR
, l.BILL_CYCLES_DEFER
, l.REVENUE_ACCOUNT
, l.INVOICE_TYPE
, l.CORRESPONDENCE_FLAG
, l.DOWN_PAYMENT
, l.ADVANCE_INSURANCE
, l.ORIGINAL_EQUIPMENT_COST
, l.SERVICING_DEALER_CODE
, l.DEALER_BUYOUT_DATE
, l.LEASE_OWNER_CODE
, l.LEASE_OWNER_DATE
, l.VENDOR_CODE
, l.SPLIT_FUNDING_COUNT
, l.DEALER_AMOUNT
, l.VENDOR_AMOUNT
, l.SALESPERSON_AMOUNT
, l.DEALER_OFFICE
, l.ASSESSMENT_YEAR
, l.PROPERTY_TAX_RATE
, l.ASSESSMENT_FACTOR
, l.MONTHLY_PROPERTY_TAX
, l.MANAGER_CODE
, l.DEALER_BUYOUT_PROGRAM
, l.SHARED_RESID_METHOD
, l.SHARED_RESID_AMOUNT
, l.SHARED_RESID_PERCENT
, l.SHARED_RESID_L_AND_D
, l.SHARED_RESID_COLLECTION_TYPE
, l.SHARED_RESID_MONTHS_OVERDUE
, l.ORIGINAL_LEASE_TERM
, l.ORIGINAL_LEASE_DATE
, l.ORIGINAL_BASE_PAYMENT
, l.ORIGINAL_MINIMUM_PAYMENTS
, l.NEW_PAYMENT_PLAN_FLAG
, l.NEW_PAYMENT_PLAN_OFFSET
, l.NEW_PAYMENT_PLAN_DATE
, l.NEW_MINIMUM_PAYMENTS
, l.BILLING_PERIOD_NUMBER
, l.BILLING_PERIOD_1_INVOICES
, l.BILLING_PERIOD_1_PAYMENT
, l.BILLING_PERIOD_2_INVOICES
, l.BILLING_PERIOD_2_PAYMENT
, l.BILLING_PERIOD_3_INVOICES
, l.BILLING_PERIOD_3_PAYMENT
, l.BILLING_PERIOD_4_INVOICES
, l.BILLING_PERIOD_4_PAYMENT
, l.BILLING_PERIOD_5_INVOICES
, l.BILLING_PERIOD_5_PAYMENT
, l.BILLING_PERIOD_6_INVOICES
, l.BILLING_PERIOD_6_PAYMENT
, l.EQUIPMENT_AMOUNT
, l.SERVICE_AMOUNT
, l.MONTHS_OF_RECOURSE
, l.VENDOR_PAID_FLAG
, l.SALESPERSON_PAID_FLAG
, l.AP_ACCOUNT
, l.GL_AP_ACCOUNT
, l.GL_OWNER_COMPANY
, l.GL_BRANCH
, l.GL_DEPARTMENT
, l.GL_EQUIPMENT
, l.GL_STATE
, l.DEALER_RECOURSE_PERCENT
, l.VENDOR_RECOURSE_PERCENT
, l.SALESPERSON_RECOURSE_PERCENT
, l.NUMBER_OF_UNITS
, l.INVOICES_SUBJECT_TO_DISCOUNT
, l.ORIGINAL_LEASE_PROGRAM
, l.MISSING_PAYMENT_COUNT
, l.BROKER_CODE
, l.REVENUE_SHARING_CODE
, l.REVENUE_SHARING_FACTOR
, l.REVENUE_SHARING_FLAG
, l.DEALER_SHARING_CODE
, l.DEALER_SHARING_FACTOR
, l.DEALER_SHARING_FLAG
, l.CHARGEBACK_RESERVE_FLAG
, l.FUNDING_FEE
, l.FUNDING_FEE_INVOICED_FLAG
, l.LEASE_REFERENCE
, l.ORIGINAL_LEASE_NUMBER
, l.ORIGINAL_ACCOUNT_NUMBER
, l.BASE_PAYMENT_TAXABLE
, l.DAY_TO_CHARGE_BACK
, l.LESSEE_FED_ID_NUMBER
, l.ORIGINAL_PURCHASE_PRICE
, l.ORIGINAL_PURCHASE_DATE
, l.ACQUISITION_PURCHASE_PRICE
, l.ACQUISITION_PURCHASE_DATE
, l.BROKER_REV_SHAR_AMT_OVERRIDE
, l.DEALER_REV_SHAR_AMT_OVERRIDE
, l.UPFRONT_TAX_FLAG
, l.UPFRONT_TAX_AMOUNT
, l.UPFRONT_TAX_BILLED
, l.SysStart
, l.SysEnd
HAVING COUNT(*) > 1
) a;
更新 3:好的，这是我能够获得的新信息。我们试图捕获 rpc_completed 事件以查看实际发生的情况。跟踪文件有 7 个不同的语句，带有不同的 event_sequence 编号。据我了解，这意味着这些语句是在不同的事务中执行的。稍后我会尝试准备更详细的更新，但现在这些语句如下(除了最后一个语句之外的所有语句都是使用 sp_prepexec 存储过程执行的):
该行实际上有 3 种不同的状态，我们称它们为 x,y,z
- 通过 PK 以
x状态更新记录——此时数据库中没有这样的记录 - 通过 PK 以
y状态更新记录——此时数据库中没有这样的记录 - 插入
x状态的记录 - INSERT 状态为
y的记录——因违反 PK 约束而失败 - UPDATE 记录到
x状态——实际上没有改变任何行，所以实际记录没有改变 - 将记录更新到
y状态——实际记录已更改 - 使用
sp_execute过程将记录更新到z状态，其中 handle_id 与上次更新相同(更新到z状态)但是通过参数传递的值是不同的
所以在这些操作结束时我们有:
原始表处于 z 状态，历史表有类似的东西(日期时间是真实值):
x状态列，2017-11-01 16:55:31.3358248，2017-11-01 16:55:31.3358248x状态列，2017-11-01 16:55:31.3358248，2017-11-01 16:55:31.3358248y状态列，2017-11-01 16:55:31.3358248，2017-11-01 16:55:41.9296659
最佳答案
时态表使用事务的开始时间 作为使用的时间戳(请参阅插入、更新和删除部分下的 Temporal Tables in MS Docs)。通过在您的事务中进行多次更新，或者在同一事务中进行插入后进行更新，您将获得具有相同开始/结束时间的给定主键值的多条记录。
链接摘录:
UPDATES: On an UPDATE, the system stores the previous value of the row in the history table and sets the value for the SysEndTime column to the begin time of the current transaction (in the UTC time zone) based on the system clock
这是一个将重现该行为的示例。请注意，ProductId = 2 的 ProductsHistory 表中有 2 个相同的 Miniature Widgets 条目。另请注意，虽然 ProductId = 1 的更新没有更改值，但它们仍然创建了相同的历史表记录。
create table test.Products (
ProductId int not null primary key,
ProductName nvarchar(100) not null,
EffectiveDate datetime2(7) generated always as row start hidden not null,
EndingDate datetime2(7) generated always as row end hidden not null,
period for system_time (EffectiveDate, EndingDate)
)
with (system_versioning = on (history_table = test.ProductsHistory));
go
begin tran
insert test.Products (ProductId, ProductName) values
(1, N'Widgets'),
(2, N'Miniature Widgets');
update test.Products set ProductName = 'Tiny Widgets' where ProductId = 2;
update test.Products set ProductName = 'Miniature Widgets' where ProductId = 2;
update test.Products set ProductName = 'Tiny Widgets' where ProductId = 2;
update test.Products set ProductName = 'Widgets' where ProductId = 1;
update test.Products set ProductName = 'Widgets' where ProductId = 1;
commit tran
select p.ProductId, p.ProductName, p.EffectiveDate, p.EndingDate
from test.Products for system_time all p;
select *
from test.ProductsHistory;
关于sql-server - 时间历史表中的重复项，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/46977409/