約3milの行を持つテーブルでSQL Serverの変更の追跡を切り替えました。
変更の追跡をオンにします。
ALTER DATABASE FooDB
SET CHANGE_TRACKING = ON
(CHANGE_RETENTION = 10 DAYS, AUTO_CLEANUP = OFF)
ALTER TABLE [dbo].[fooTable]
ENABLE CHANGE_TRACKING
WITH (TRACK_COLUMNS_UPDATED = OFF)
行を個別に編集すると、すべて正常に、挿入/更新/削除ごとに変更が保存されます。
複数の行を更新する更新クエリを実行すると、更新のSECOND行の変更レコードしか取得できません。
そう:
UPDATE fooTable SET name = UPPER(name) where id between 100 and 200
続いて(各行で実際の更新が行われるようにするため)
UPDATE fooTable SET name = LOWER(name) where id between 100 and 200
レコード101のみの変更レコードになります。
SQL Express 2014
私は何が起こっているのかを理解しました。
私が行った悪い仮定は、変更によって4つの行が一度に更新される場合、テーブルのSYS_CHANGE_VERSIONが4増えるということです。チェンジテーブルには4つの変更がありますが、バージョンは1だけ上がります(複数のレコードを変更した単一の変更です)。
自分でテストしたい人は、以下のコードを使用できます。
-- 1. Create Table
CREATE TABLE dbo.fooTable(
[ID] [int] IDENTITY(1,1) NOT FOR REPLICATION NOT NULL,
[Title] [nvarchar](20) NULL,
[Surname] [nvarchar](128) NULL,
[MiddleNames] [nvarchar](128) NULL,
[Firstname] [nvarchar](128) NULL,
[CreateDate] [datetime2](7) NOT NULL CONSTRAINT [DF_CustomerProfile_CreateDate_I] DEFAULT (getdate()),
[LastModifiedDate] [datetime2](7) NOT NULL CONSTRAINT [DF_CustomerProfile_LastModifiedDate_I] DEFAULT (getdate()),
CONSTRAINT [PK_fooTable_I] PRIMARY KEY CLUSTERED
(
[ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON)
)
GO
-- 2. Insert dummy data
insert into fooTable (Title, Firstname, MiddleNames, Surname, CreateDate, lastModifiedDate)
values ('Mr','John',null,'Smith',GetDate()-5, getdate())
insert into fooTable (Title, Firstname, MiddleNames, Surname, CreateDate, lastModifiedDate)
values ('Mrs','Mary','Beth','Jones',GetDate()-5, getdate())
insert into fooTable (Title, Firstname, MiddleNames, Surname, CreateDate, lastModifiedDate)
values ('Ms','Thanh',null,'Nguyen',GetDate()-5, getdate())
insert into fooTable (Title, Firstname, MiddleNames, Surname, CreateDate, lastModifiedDate)
values ('Dr','Lee','Evan','Oscars',GetDate()-5, getdate())
-- 3. Turn on Change Tracking
-- Database
ALTER DATABASE fooDB
SET CHANGE_TRACKING = ON
(CHANGE_RETENTION = 10 DAYS, AUTO_CLEANUP = OFF)
-- Tables
ALTER TABLE dbo.fooTable
ENABLE CHANGE_TRACKING
WITH (TRACK_COLUMNS_UPDATED = OFF)
-- 4. Check current version
Select CHANGE_TRACKING_CURRENT_VERSION() -- Should be Zero if you have never turned change tracking on before.
-- 5. Make a single change
Update fooTable set MiddleNames = 'Arthur' where Surname = 'Smith'
-- 6. Check current version, should have gone up by 1
Select CHANGE_TRACKING_CURRENT_VERSION() -- Should be 1 if you have never turned change tracking on before.
-- 7. See the change, should be Type U on record with ID 1
DECLARE @version bigint
SET @version = CHANGE_TRACKING_CURRENT_VERSION()-1
Select CT.*
FROM CHANGETABLE(CHANGES dbo.fooTable, @version) CT
-- 8. If everything is OK up to here, that's great. Now we have a problem.
-- Update all the rows in the table
Update fooTable set lastModifiedDate = Getdate() + 5
-- 9. Check current version, I expected it would go up by 4, one update for each record
Select CHANGE_TRACKING_CURRENT_VERSION() -- Should be 5 if you have never turned change tracking on before.
-- 10. View all changes for the table. There should be 4 (the first one will be gone now.)
Select CT.*
FROM CHANGETABLE(CHANGES dbo.fooTable, 0) CT
-- Observe that each row has the same SYS_CHANGE_VERSION which means I need to deal with it and move on.