使用Apworks开发基于CQRS架构的应用程序（七）：配置数据库

到目前为止，我们还未涉及任何数据库的配置工作。本章节将简单介绍基于Apworks的应用程序的数据库配置。在SQL Server中（目前的Apworks版本仅支持SQL Server）创建两个数据库：TinyLibraryEventDB和TinyLibraryQueryDB，然后分别执行如下SQL脚本：

• TinyLibraryEventDB
  

  USE TinyLibraryEventDB;
  /****** Object:  Table [dbo].[DomainEvents]    Script Date: 12/24/2010 20:27:20 ******/
  IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[DomainEvents]') AND type in (N'U'))
  DROP TABLE [dbo].[DomainEvents]
  GO
  /****** Object:  Table [dbo].[Snapshots]    Script Date: 12/24/2010 20:27:20 ******/
  IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[Snapshots]') AND type in (N'U'))
  DROP TABLE [dbo].[Snapshots]
  GO
  /****** Object:  Table [dbo].[Snapshots]    Script Date: 12/24/2010 20:27:20 ******/
  SET ANSI_NULLS ON
  GO
  SET QUOTED_IDENTIFIER ON
  GO
  IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[Snapshots]') AND type in (N'U'))
  BEGIN
  CREATE TABLE [dbo].[Snapshots](
   [Id] [bigint] IDENTITY(1,1) NOT NULL,
   [Timestamp] [datetime] NOT NULL,
   [SnapshotData] [varbinary](max) NOT NULL,
   [AggregateRootId] [bigint] NOT NULL,
   [AggregateRootType] [nvarchar](max) COLLATE Chinese_PRC_CI_AS NOT NULL,
   [SnapshotType] [nvarchar](max) COLLATE Chinese_PRC_CI_AS NOT NULL,
   [Version] [bigint] NOT NULL,
   [Branch] [bigint] NOT NULL,
   CONSTRAINT [PK_Snapshots] PRIMARY KEY CLUSTERED
  (
   [Id] ASC
  )WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON)
  )
  END
  GO
  /****** Object:  Table [dbo].[DomainEvents]    Script Date: 12/24/2010 20:27:20 ******/
  SET ANSI_NULLS ON
  GO
  SET QUOTED_IDENTIFIER ON
  GO
  IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[DomainEvents]') AND type in (N'U'))
  BEGIN
  CREATE TABLE [dbo].[DomainEvents](
   [Id] [bigint] IDENTITY(1,1) NOT NULL,
   [AggregateRootId] [bigint] NOT NULL,
   [AggregateRootType] [nvarchar](max) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
   [Timestamp] [datetime] NOT NULL,
   [Version] [bigint] NOT NULL,
   [Branch] [bigint] NOT NULL,
   [TargetType] [nvarchar](max) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
   [Data] [varbinary](max) NOT NULL,
   CONSTRAINT [PK_DomainEvents] PRIMARY KEY CLUSTERED
  (
   [Id] ASC
  )WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON)
  )
  END
  GO

• TinyLibraryQueryDB
  

  USE TinyLibraryQueryDB;
  /****** Object:  Table [dbo].[Books]    Script Date: 12/14/2010 14:12:31 ******/
  IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[Books]') AND type in (N'U'))
  DROP TABLE [dbo].[Books]
  GO
  /****** Object:  Table [dbo].[Readers]    Script Date: 12/14/2010 14:12:31 ******/
  IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[Readers]') AND type in (N'U'))
  DROP TABLE [dbo].[Readers]
  GO
  /****** Object:  Table [dbo].[Registrations]    Script Date: 12/14/2010 14:12:31 ******/
  IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[Registrations]') AND type in (N'U'))
  DROP TABLE [dbo].[Registrations]
  GO
  /****** Object:  Table [dbo].[Registrations]    Script Date: 12/14/2010 14:12:31 ******/
  SET ANSI_NULLS ON
  GO
  SET QUOTED_IDENTIFIER ON
  GO
  IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[Registrations]') AND type in (N'U'))
  BEGIN
  CREATE TABLE [dbo].[Registrations](
   [Id] [bigint] IDENTITY(1,1) NOT NULL,
   [BookId] [bigint] NOT NULL,
   [ReaderId] [bigint] NOT NULL,
   [ReaderName] [nvarchar](max) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
   [ReaderLoginName] [nvarchar](max) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
   [BookTitle] [nvarchar](255) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
   [BookPublisher] [nvarchar](255) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
   [BookPubDate] [datetime] NOT NULL,
   [BookISBN] [nvarchar](255) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
   [BookPages] [int] NOT NULL,
   [RegistrationDate] [datetime] NULL,
   [DueDate] [datetime] NULL,
   [ReturnedDate] [datetime] NULL,
   [Returned] [bit] NULL,
   CONSTRAINT [PK_Registrations] PRIMARY KEY CLUSTERED
  (
   [Id] ASC
  )WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON)
  )
  END
  GO
  /****** Object:  Table [dbo].[Readers]    Script Date: 12/14/2010 14:12:31 ******/
  SET ANSI_NULLS ON
  GO
  SET QUOTED_IDENTIFIER ON
  GO
  IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[Readers]') AND type in (N'U'))
  BEGIN
  CREATE TABLE [dbo].[Readers](
   [Id] [bigint] IDENTITY(1,1) NOT NULL,
   [LoginName] [nvarchar](max) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
   [Name] [nvarchar](max) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
   [AggregateRootId] [bigint] NOT NULL,
   CONSTRAINT [PK_Readers] PRIMARY KEY CLUSTERED
  (
   [Id] ASC
  )WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON)
  )
  END
  GO
  /****** Object:  Table [dbo].[Books]    Script Date: 12/14/2010 14:12:31 ******/
  SET ANSI_NULLS ON
  GO
  SET QUOTED_IDENTIFIER ON
  GO
  IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[Books]') AND type in (N'U'))
  BEGIN
  CREATE TABLE [dbo].[Books](
   [Id] [bigint] IDENTITY(1,1) NOT NULL,
   [Title] [nvarchar](255) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
   [Publisher] [nvarchar](255) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
   [PubDate] [datetime] NOT NULL,
   [ISBN] [nvarchar](255) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
   [Pages] [int] NOT NULL,
   [Lent] [bit] NULL,
   [AggregateRootId] [bigint] NOT NULL,
   [LendTo] [nvarchar](255) COLLATE SQL_Latin1_General_CP1_CI_AS NULL,
   CONSTRAINT [PK_Books] PRIMARY KEY CLUSTERED
  (
   [Id] ASC
  )WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON)
  )
  END
  GO

由于我们所使用的数据库系统是SQL Server，对于上面的TinyLibraryEventDB而言，它就是直接使用的Apworks应用开发框架中自带的SQL脚本。开发人员可以在Apworks的安装目录中找到该脚本文件。

就关系型数据库而言，我们需要一个额外的步骤去维护对象与数据表的映射关系。Apworks采用的是XML Storage Mapping Schema来维护这样的关系。

1. 向TinyLibrary.Services项目添加一个新的XML文件，将其更名为DomainEventStorageMappings.xml，然后输入下面的内容
   

   <?xml version="1.0" encoding="utf-8"?>
   <StorageMappingSchema>
     <DataTypes>
       <DataType FullName="Apworks.Events.Storage.DomainEventDataObject" MapTo="DomainEvents">
         <Properties>
           <Property Name="Id" MapTo="Id" Identity="true" AutoGenerate="true"/>
         </Properties>
       </DataType>
       <DataType FullName="Apworks.Events.Storage.SnapshotDataObject" MapTo="Snapshots">
         <Properties>
           <Property Name="Id" MapTo="Id" Identity="true" AutoGenerate="true"/>
         </Properties>
       </DataType>
     </DataTypes>
   </StorageMappingSchema>

2. 向TinyLibrary.Services项目添加一个新的XML文件，将其更名为QueryObjectStorageMappings.xml，然后输入下面的内容
   

   <?xml version="1.0" encoding="UTF-8"?>
   <StorageMappingSchema>
     <DataTypes>
       <DataType FullName="TinyLibrary.QueryObjects.ReaderObject" MapTo="Readers">
         <Properties>
           <Property Name="Id" MapTo="Id" Identity="true" AutoGenerate="true"/>
         </Properties>
       </DataType>
       <DataType FullName="TinyLibrary.QueryObjects.BookObject" MapTo="Books">
         <Properties>
           <Property Name="Id" MapTo="Id" Identity="true" AutoGenerate="true"/>
         </Properties>
       </DataType>
       <DataType FullName="TinyLibrary.QueryObjects.RegistrationObject" MapTo="Registrations">
         <Properties>
           <Property Name="Id" MapTo="Id" Identity="true" AutoGenerate="true"/>
           <Property Name="BookAggregateRootId" MapTo="BookId"/>
           <Property Name="ReaderAggregateRootId" MapTo="ReaderId"/>
         </Properties>
       </DataType>
     </DataTypes>
   </StorageMappingSchema>

以下是这些XML文件的XSD结构，这个XSD Schema也被包含在Apworks应用开发框架的安装目录中。

<?xml version="1.0" encoding="UTF-8"?>
<!-- edited with XMLSpy v2009 (http://www.altova.com) by Administrator (EMBRACE) -->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified">
 <xs:element name="StorageMappingSchema">
  <xs:annotation>
   <xs:documentation>Represents the schema for storage mapping.</xs:documentation>
  </xs:annotation>
  <xs:complexType>
   <xs:sequence minOccurs="0">
    <xs:element ref="DataTypes"/>
   </xs:sequence>
  </xs:complexType>
 </xs:element>
 <xs:element name="DataTypes">
  <xs:complexType>
   <xs:sequence minOccurs="0" maxOccurs="unbounded">
    <xs:element ref="DataType"/>
   </xs:sequence>
  </xs:complexType>
 </xs:element>
 <xs:element name="DataType">
  <xs:complexType>
   <xs:sequence minOccurs="0">
    <xs:element ref="Properties"/>
   </xs:sequence>
   <xs:attribute name="FullName" type="xs:string" use="required"/>
   <xs:attribute name="MapTo" type="xs:string" use="required"/>
  </xs:complexType>
 </xs:element>
 <xs:element name="Properties">
  <xs:complexType>
   <xs:sequence minOccurs="0" maxOccurs="unbounded">
    <xs:element ref="Property"/>
   </xs:sequence>
  </xs:complexType>
 </xs:element>
 <xs:element name="Property">
  <xs:complexType>
   <xs:attribute name="Name" type="xs:string" use="required"/>
   <xs:attribute name="MapTo" type="xs:string" use="required"/>
   <xs:attribute name="Identity" type="xs:boolean" use="optional"/>
   <xs:attribute name="AutoGenerate" type="xs:boolean" use="optional"/>
  </xs:complexType>
 </xs:element>
</xs:schema>