使用T4模板基于POCO生成多个类

当我向数据库添加表时，我正在寻找一种提高工作效率的方法。一般来说，当我添加新表时，我必须执行以下步骤。

1. 将表添加到数据库（简单）
2. 创建相应的 EF Code First 类。 （我不使用数据库迁移）
3. 创建一个与 #2 中创建的 EF 类匹配的 POCO 模型。
4. 创建存储库类
5. 为 CQRS 模式创建命令和处理程序
6. 为新创建的类创建 AutoMapper 地图

我最近创建了一个新网站，其中要求首先使用 EF 数据库，我了解了它如何使用 tt 文件生成类。这让我想到我可以以某种方式使用这些模板（新模板）来生成基本 CRUD 操作的所有标准支持项。问题是我没有创建这些模板的经验，也不知道从哪里开始。

要生成的示例代码：

存储库

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

public interface IUsersRepository : IRepository<Users>
{
}

public class UsersRepository : RepositoryBase<Users>, IUsersRepository
{
    public UsersRepository(IDatabaseFactory databaseFactory)
        : base(databaseFactory)
    {
    }

}

基于 EDMX（或 Code First）生成的实体的基本模型

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

public class User 
{
    public int UserId { get; set; }
    public string UserRole { get; set; }
    public string UserName { get; set; }
}

Command

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

public class AddUpdateUserPayoutCommand : CommandBase, ICommand
{
    public int UserId { get; set; }
    public string UserRole { get; set; }
    public string UserName { get; set; }
}

命令处理程序

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

public class AddUpdateUserHandler: ICommandHandler<AddUpdateUserCommand>
{
    private readonly IUsersRepository _repository;
    private readonly IUnitOfWork _unitOfWork;
    public AddUpdateUserPayoutHandler(IUsersRepository repository, IUnitOfWork unitOfWork)
    {
        _repository = repository;
        _unitOfWork = unitOfWork;
    }
    public ICommandResult Execute(AddUpdateUserCommand command)
    {
        Users entity;
        if (command.UserId == 0)
        {
            entity = AutoMapper.Mapper.Map<Users>(command);
            _repository.Add(entity);
        }
        else
        {
            entity = _repository.Get(x=>x.UserId==command.UserId);
            entity = AutoMapper.Mapper.Map<Users>(command);
            _repository.Update(entity);
        }
        _unitOfWork.Commit(command.UserId);         

        return new CommandResult(true,entity.UserId);
    }
}

Automapper 地图 - 放置在 app_start 中

Mapper.CreateMap<User, AddUpdateUserCommand>();

此示例并不是一个可以剪切粘贴到项目中的解决方案，而是作为一个示例，说明如何编写从数据库模式生成代码的模板。

构建一个快速模板来演示如何生成代码工件。

您可以在这里找到整个项目：https://github.com/mrange/CodeStack/tree/master/q18787460/ModelGenerator https://github.com/mrange/CodeStack/tree/master/q18787460/ModelGenerator

模板本身使用 T4Include.Schema 来获取数据库架构。 SMO 也完全可以合法使用，我只是更喜欢 T4Include.Schema 因为它的性能并且它只依赖于 SqlConnection （T4Include.Schema 是 SqlConnection 的一部分）https://www.nuget.org/packages/T4IncludeTemplate/ https://www.nuget.org/packages/T4IncludeTemplate/).

模板的基本策略是获取所有表并迭代它们生成代码工件。

<#@ include file="$(SolutionDir)\packages\T4IncludeTemplate.1.0.3\T4\Schema.ttinclude"#>

<#

    // The namespace surrounding the code
    var namespaceName               = "ModelGenerator";
    var connectionString            = @"Data Source=localhost\SQLEXPRESS;Initial Catalog=TestDB;Integrated Security=True";
    var schema                      = GetSchema (connectionString);
    Func<string, string> justify    = s => LeftJustify (s, 40);

    var tables                      = schema
        .SchemaObjects
        .Where (so => so.Type == SchemaObject.SchemaObjectType.Table)
        .ToArray ()
        ;
#>

namespace <#=namespaceName#>
{
<#
    foreach (var table in tables)
    {
#>
    /// <summary>
    /// Repository interface for <#=table.Name#>
    /// </summary>
    partial interface I<#=table.Name#>Repository : IRepository<<#=table.Name#>>
    {
    }

    /// <summary>
    /// Repository class for <#=table.Name#>
    /// </summary>
    partial class <#=table.Name#>Repository : RepositoryBase<<#=table.Name#>>, I<#=table.Name#>Repository
    {
    }

    /// <summary>
    /// Poco class for <#=table.Name#>
    /// </summary>
    partial class <#=table.Name#>
    {
<#
    foreach (var column in table.Columns)
    {
#>
        public <#=justify (column.CsTypeName)#> <#=justify (column.Name)#>{ get; set; }
<#
    }
#>
    } 

    /// <summary>
    /// Command class for <#=table.Name#>
    /// </summary>
    partial class <#=table.Name#>Command : CommandBase, ICommand
    {
<#
    foreach (var column in table.Columns)
    {
#>
        public <#=justify (column.CsTypeName)#> <#=justify (column.Name)#> { get; set; }
<#
    }
#> 
    }

    /// <summary>
    /// Command handler class for <#=table.Name#>
    /// </summary>
    partial class <#=table.Name#>CommandHandler : ICommandHandler<<#=table.Name#>Command>
    {
        private readonly IUsersRepository _repository;
        private readonly IUnitOfWork _unitOfWork;
        public <#=table.Name#>CommandHandler(IUsersRepository repository, IUnitOfWork unitOfWork)
        {
            _repository = repository;
            _unitOfWork = unitOfWork;
        }

        public ICommandResult Execute(<#=table.Name#>Command command)
        {
            <#=table.Name#> entity;

<#
    var identityColumn = table.Columns.FirstOrDefault (c => c.IsIdentity);
    if (identityColumn == null)
    {
#>
@@@ ERROR__NO_IDENTITY_COLUMN_FOUND_FOR: <#=table.FullName#>
<#
    }
    else
    {
#>
            if (command.<#=identityColumn.Name#> == 0)
            {
                entity = AutoMapper.Mapper.Map<<#=table.Name#>>(command);
                _repository.Add(entity);
            }
            else
            {
                entity = _repository.Get(x=>x.UserId==command.<#=identityColumn.Name#>);
                entity = AutoMapper.Mapper.Map<<#=table.Name#>>(command);
                _repository.Update(entity);
            }
            _unitOfWork.Commit(command.<#=identityColumn.Name#>);         

            return new CommandResult(true,entity.<#=identityColumn.Name#>);
<#
    }
#>
        }
    }
<#
    }
#>
}

<#+

    static Schema GetSchema (string connectionString) 
    {
        using (var connection = new SqlConnection (connectionString))
        {
            connection.Open ();

            return new Schema (connection);
        }
    }


#>

最后生成的代码如下所示（对于我的测试数据库，只有一个表：CUS_Customer）

// ############################################################################
// #                                                                          #
// #        ---==>  T H I S  F I L E  I S   G E N E R A T E D  <==---         #
// #                                                                          #
// # This means that any edits to the .cs file will be lost when its          #
// # regenerated. Changes should instead be applied to the corresponding      #
// # template file (.tt)                                                      #
// ############################################################################











namespace ModelGenerator
{
    /// <summary>
    /// Repository interface for CUS_Customer
    /// </summary>
    partial interface ICUS_CustomerRepository : IRepository<CUS_Customer>
    {
    }

    /// <summary>
    /// Repository class for CUS_Customer
    /// </summary>
    partial class CUS_CustomerRepository : RepositoryBase<CUS_Customer>, ICUS_CustomerRepository
    {
    }

    /// <summary>
    /// Poco class for CUS_Customer
    /// </summary>
    partial class CUS_Customer
    {
        public System.Int64                             CUS_ID                                  { get; set; }
        public System.String                            CUS_FirstName                           { get; set; }
        public System.String                            CUS_LastName                            { get; set; }
        public System.DateTime                          CUS_Born                                { get; set; }
        public System.DateTime                          CUS_Created                             { get; set; }
    } 

    /// <summary>
    /// Command class for CUS_Customer
    /// </summary>
    partial class CUS_CustomerCommand : CommandBase, ICommand
    {
        public System.Int64                             CUS_ID                                   { get; set; }
        public System.String                            CUS_FirstName                            { get; set; }
        public System.String                            CUS_LastName                             { get; set; }
        public System.DateTime                          CUS_Born                                 { get; set; }
        public System.DateTime                          CUS_Created                              { get; set; }

    }

    /// <summary>
    /// Command handler class for CUS_Customer
    /// </summary>
    partial class CUS_CustomerCommandHandler : ICommandHandler<CUS_CustomerCommand>
    {
        private readonly IUsersRepository _repository;
        private readonly IUnitOfWork _unitOfWork;
        public CUS_CustomerCommandHandler(IUsersRepository repository, IUnitOfWork unitOfWork)
        {
            _repository = repository;
            _unitOfWork = unitOfWork;
        }

        public ICommandResult Execute(CUS_CustomerCommand command)
        {
            CUS_Customer entity;

            if (command.CUS_ID == 0)
            {
                entity = AutoMapper.Mapper.Map<CUS_Customer>(command);
                _repository.Add(entity);
            }
            else
            {
                entity = _repository.Get(x=>x.UserId==command.CUS_ID);
                entity = AutoMapper.Mapper.Map<CUS_Customer>(command);
                _repository.Update(entity);
            }
            _unitOfWork.Commit(command.CUS_ID);         

            return new CommandResult(true,entity.CUS_ID);
        }
    }
}

如果您从 github 拉取该项目并将连接字符串更新为与您相关的内容，它应该会为您生成代码。如果您遇到任何问题，请回复此帖子。