EF Core 2.0中开启Transaction事务会对DbContext创建和关闭数据库连接的行为有所影响

CREATE TABLE [dbo].[Book](
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [BookName] [nvarchar](50) NULL,
    [BookDescription] [nvarchar](50) NULL,
    [ISBN] [nvarchar](20) NULL,
    [CreateTime] [datetime] NULL,
 CONSTRAINT [PK_Book] 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

ALTER TABLE [dbo].[Book] ADD  CONSTRAINT [DF_Book_CreateTime]  DEFAULT (getdate()) FOR [CreateTime]
GO

INSERT [dbo].[Book] ([BookName], [BookDescription], [ISBN]) VALUES (N‘Chinese‘, N‘Chinese‘, N‘0001‘)
GO
INSERT [dbo].[Book] ([BookName], [BookDescription], [ISBN]) VALUES (N‘English‘, N‘English‘, N‘0002‘)
GO
INSERT [dbo].[Book] ([BookName], [BookDescription], [ISBN]) VALUES (N‘Japanese‘, N‘Japanese‘, N‘0003‘)
GO
INSERT [dbo].[Book] ([BookName], [BookDescription], [ISBN]) VALUES (N‘Russian‘, N‘Russian‘, N‘0004‘)
GO
INSERT [dbo].[Book] ([BookName], [BookDescription], [ISBN]) VALUES (N‘Italian‘, N‘Italian‘, N‘0005‘)
GO

using System;
using System.Collections.Generic;

namespace EFCoreDB.Entities
{
    public partial class Book
    {
        public int Id { get; set; }
        public string BookName { get; set; }
        public string BookDescription { get; set; }
        public string Isbn { get; set; }
        public DateTime? CreateTime { get; set; }
    }
}