将“正常”表作为临时表答案

【问题标题】：Make a "normal" table as temporal table将“正常”表作为临时表
【发布时间】：2021-04-11 13:36:53
【问题描述】：

我有一个这样创建的表：

CREATE TABLE address_user 
(
    [username] VARCHAR(13) NOT NULL,
    [address] CHAR(58) NOT NULL,
    [id] BIGINT NOT NULL,

    CONSTRAINT [PK_ address_user] 
        PRIMARY KEY CLUSTERED ([id] ASC)
);

现在我希望能够保留这个表的历史修改，所以我想把它做成临时表。我知道创建临时表的脚本，最终结果应该是：

CREATE TABLE address_user 
(
    [username] VARCHAR(13) NOT NULL,
    [address] CHAR(58) NOT NULL,
    [id] BIGINT NOT NULL,
    [sys_start_time] DATETIME2(7) 
        GENERATED ALWAYS AS ROW START HIDDEN NOT NULL,
    [sys_end_time] DATETIME2 (7) 
        GENERATED ALWAYS AS ROW END HIDDEN NOT NULL,

    PERIOD FOR SYSTEM_TIME ([sys_start_time], [sys_end_time]),
    CONSTRAINT [PK_ address_user] 
        PRIMARY KEY CLUSTERED ([id] ASC)
)
WITH (SYSTEM_VERSIONING = ON (HISTORY_TABLE=[dbo].[address_user_history], DATA_CONSISTENCY_CHECK=ON));

执行此操作的简单方法是删除之前的表，然后使用良好的架构重新创建表。

但是，我的表中有很多信息，保存数据并删除表，重新创建并重新插入数据让我很不舒服。

因此，如果您有解决方案来转换临时表中的第一个表，而无需删除所有内容并重新创建它，那应该会有很大帮助！

【问题讨论】：

标签： sql-server temporal-tables

【解决方案1】：

创建新表address_user_new，插入数据，然后使用sp_rename将address_user重命名为address_user_old，将address_user_new重命名为address_user。这一切都可以在事务中完成，以确保转换是原子的并且明显是瞬时的。例如

if object_id('address_user') is not null
  ALTER TABLE address_user SET ( SYSTEM_VERSIONING = OFF)
go
if object_id('address_user_new') is not null
  ALTER TABLE address_user_new SET ( SYSTEM_VERSIONING = OFF)
go
drop table if exists address_user
drop table if exists address_user_history
drop table if exists address_user_new
drop table if exists address_user_old
go

CREATE TABLE address_user 
(
    [username] VARCHAR(13) NOT NULL,
    [address] CHAR(58) NOT NULL,
    [id] BIGINT NOT NULL,

    CONSTRAINT [PK_address_user] 
        PRIMARY KEY CLUSTERED ([id] ASC)
);

go
CREATE TABLE address_user_new 
(
    [username] VARCHAR(13) NOT NULL,
    [address] CHAR(58) NOT NULL,
    [id] BIGINT NOT NULL,
    [sys_start_time] DATETIME2(7) 
        GENERATED ALWAYS AS ROW START HIDDEN NOT NULL,
    [sys_end_time] DATETIME2 (7) 
        GENERATED ALWAYS AS ROW END HIDDEN NOT NULL,

    PERIOD FOR SYSTEM_TIME ([sys_start_time], [sys_end_time]),
    CONSTRAINT [PK_address_user_new] 
        PRIMARY KEY CLUSTERED ([id] ASC)
)
WITH (SYSTEM_VERSIONING = ON (HISTORY_TABLE=[dbo].[address_user_history], DATA_CONSISTENCY_CHECK=ON));

go


set xact_abort on
begin transaction

insert into address_user_new(username,address,id)
select username,address,id
from address_user with (tablockx)

exec sp_rename 'address_user', 'address_user_old', 'OBJECT'
exec sp_rename 'PK_address_user', 'PK_address_user_old', 'OBJECT'

exec sp_rename 'address_user_new', 'address_user', 'OBJECT'
exec sp_rename 'PK_address_user_new', 'PK_address_user', 'OBJECT'

commit transaction

【讨论】：