迁移计算列
内存优化的表中不支持计算列。 但是，可模拟计算列。
将基于磁盘的表迁移到内存优化的表时，应考虑是否需要使计算列持久化。 内存优化的表和本机编译的存储过程的性能特征不同，因此可能不需要持久化。
非持久化计算列
若要模拟非持久化计算列的效果，请在内存优化的表上创建一个视图。 在定义该视图的 SELECT 语句中，将计算列定义添加到该视图中。 除了在本机编译的存储过程中以外，使用计算列中的值的查询应从该视图进行读取。 在本机编译的存储过程中，应根据计算列定义更新任何 select、update 或 delete 语句。
-- Schema for the table dbo.OrderDetails:
-- OrderId int not null primary key,
-- ProductId int not null,
-- SalePrice money not null,
-- Quantity int not null,
-- Total money not null
--
-- Total is computed as SalePrice * Quantity and is not persisted.
CREATE VIEW dbo.v_order_details AS
SELECT
OrderId,
ProductId,
SalePrice,
Quantity,
Quantity * SalePrice AS Total
FROM dbo.order_details
持久化计算列
若要模拟持久化计算列的效果，请创建一个存储过程用于插入到表中，创建另一个存储过程用于更新表。 插入或更新表时，调用这些存储过程以执行这些任务。 在存储过程中，根据输入内容算出计算字段的值，方式很像在基于磁盘的原始表上定义计算列。 然后，在存储过程中按需插入或更新表。
-- Schema for the table dbo.OrderDetails:
-- OrderId int not null primary key,
-- ProductId int not null,
-- SalePrice money not null,
-- Quantity int not null,
-- Total money not null
--
-- Total is computed as SalePrice * Quantity and is persisted.
-- we need to create insert and update procedures to calculate Total.
CREATE PROCEDURE sp_insert_order_details
@OrderId int, @ProductId int, @SalePrice money, @Quantity int
WITH NATIVE_COMPILATION, SCHEMABINDING, EXECUTE AS OWNER
AS BEGIN ATOMIC WITH (LANGUAGE = N'english', TRANSACTION ISOLATION LEVEL = SNAPSHOT)
-- compute the value here.
-- this stored procedure works with single rows only.
-- for bulk inserts, accept a table-valued parameter into the stored procedure
-- and use an INSERT INTO SELECT statement.
DECLARE @total money = @SalePrice * @Quantity
INSERT INTO dbo.OrderDetails (OrderId, ProductId, SalePrice, Quantity, Total)
VALUES (@OrderId, @ProductId, @SalePrice, @Quantity, @total)
END
GO
CREATE PROCEDURE sp_update_order_details_by_id
@OrderId int, @ProductId int, @SalePrice money, @Quantity int
WITH NATIVE_COMPILATION, SCHEMABINDING, EXECUTE AS OWNER
AS BEGIN ATOMIC WITH (LANGUAGE = N'english', TRANSACTION ISOLATION LEVEL = SNAPSHOT)
-- compute the value here.
-- this stored procedure works with single rows only.
DECLARE @total money = @SalePrice * @Quantity
UPDATE dbo.OrderDetails
SET ProductId = @ProductId, SalePrice = @SalePrice, Quantity = @Quantity, Total = @total
WHERE OrderId = @OrderId
END
GO