dotnetefcore脚手架快速搭建办法

简书链接:dotnetefcore脚手架快速搭建办法
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刚开始学ef框架，从网上模仿写的，代码，结果后面执行出了问题。。
发现有一个更快的方法
先配置好环境
https://docs.microsoft.com/en-us/ef/core/cli/dotnet

dotnet tool install --global dotnet-ef
dotnet tool update --global dotnet-ef
dotnet add package Microsoft.EntityFrameworkCore.Design
dotnet ef

进入项目
PS C:\Users\惠普\source\repos\CoreWebApi_>
网上的教程输入dotnet ef提示
无法执行，因为找不到指定的命令或文件。
可能的原因包括:
*内置的 dotnet 命令拼写错误。
原因就是上面dotnet tool install --global dotnet-ef这个东西没装
dotnet ef dbcontext scaffold Server=localhost;Database=efcorelearn;User=root;Password=password; Pomelo.EntityFrameworkCore.MySql -o Models

上面的代码就是连接数据库然后进行分析产生对应的代码放到Models文件夹里面
DigitalTwinContext.cs的命名是根据数据库命名自动识别生成的。
相当规范，于是我删除了我手动写的 一套

主要看看怎么 context写的

using System;
using System.Collections.Generic;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata;

namespace CoreWebApi_.Models
{
    public partial class DigitalTwinContext : DbContext
    {
        public DigitalTwinContext()
        {
        }

        public DigitalTwinContext(DbContextOptions<DigitalTwinContext> options)
            : base(options)
        {
        }

        public virtual DbSet<Node> Nodes { get; set; } = null!;
        public virtual DbSet<NodesTemp> NodesTemps { get; set; } = null!;
        public virtual DbSet<View> Views { get; set; } = null!;

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            if (!optionsBuilder.IsConfigured)
            {
#warning To protect potentially sensitive information in your connection string, you should move it out of source code. You can avoid scaffolding the connection string by using the Name= syntax to read it from configuration - see https://go.microsoft.com/fwlink/?linkid=2131148. For more guidance on storing connection strings, see http://go.microsoft.com/fwlink/?LinkId=723263.
                optionsBuilder.UseSqlServer("Data Source=192.168.1.124;Initial Catalog=DigitalTwin;User ID=SA;Password=12345678;Connect Timeout=15");
            }
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Node>(entity =>
            {
                entity.HasNoKey();

                entity.Property(e => e.Descript)
                    .HasMaxLength(500)
                    .IsUnicode(false);

                entity.Property(e => e.Flag)
                    .HasColumnName("flag")
                    .HasDefaultValueSql("((0))");

                entity.Property(e => e.Id)
                    .ValueGeneratedOnAdd()
                    .HasColumnName("id");

                entity.Property(e => e.ItemDescript)
                    .HasMaxLength(50)
                    .IsUnicode(false)
                    .HasColumnName("itemDescript");

                entity.Property(e => e.ItemName)
                    .HasMaxLength(50)
                    .IsUnicode(false)
                    .HasColumnName("itemName");

                entity.Property(e => e.Name)
                    .HasMaxLength(50)
                    .IsUnicode(false);

                entity.Property(e => e.Parent)
                    .HasColumnName("parent")
                    .HasDefaultValueSql("((0))");

                entity.Property(e => e.ParentId).HasColumnName("parentId");

                entity.Property(e => e.Tag)
                    .HasMaxLength(50)
                    .IsUnicode(false)
                    .HasColumnName("tag");
            });

            modelBuilder.Entity<NodesTemp>(entity =>
            {
                entity.HasNoKey();

                entity.ToTable("NodesTemp");

                entity.Property(e => e.Descript)
                    .HasMaxLength(500)
                    .IsUnicode(false);

                entity.Property(e => e.Id)
                    .ValueGeneratedOnAdd()
                    .HasColumnName("id");

                entity.Property(e => e.ItemDescript)
                    .HasMaxLength(50)
                    .IsUnicode(false)
                    .HasColumnName("itemDescript");

                entity.Property(e => e.ItemName)
                    .HasMaxLength(50)
                    .IsUnicode(false)
                    .HasColumnName("itemName");

                entity.Property(e => e.Name)
                    .HasMaxLength(50)
                    .IsUnicode(false);

                entity.Property(e => e.ParentId).HasColumnName("parentId");

                entity.Property(e => e.Tag)
                    .HasMaxLength(50)
                    .IsUnicode(false)
                    .HasColumnName("tag");
            });

            modelBuilder.Entity<View>(entity =>
            {
                entity.HasNoKey();

                entity.Property(e => e.Data)
                    .HasMaxLength(50)
                    .IsUnicode(false)
                    .HasColumnName("data");

                entity.Property(e => e.Height).HasColumnName("height");

                entity.Property(e => e.Id)
                    .ValueGeneratedOnAdd()
                    .HasColumnName("id");

                entity.Property(e => e.Is3d).HasColumnName("is3d");

                entity.Property(e => e.Parent).HasColumnName("parent");

                entity.Property(e => e.ParentName)
                    .HasMaxLength(50)
                    .IsUnicode(false)
                    .HasColumnName("parentName");

                entity.Property(e => e.Scale)
                    .HasColumnName("scale")
                    .HasDefaultValueSql("((1))");

                entity.Property(e => e.Tag)
                    .HasMaxLength(50)
                    .IsUnicode(false)
                    .HasColumnName("tag");

                entity.Property(e => e.Title)
                    .HasMaxLength(50)
                    .IsUnicode(false)
                    .HasColumnName("title");

                entity.Property(e => e.Type)
                    .HasMaxLength(50)
                    .IsUnicode(false)
                    .HasColumnName("type");

                entity.Property(e => e.Width).HasColumnName("width");

                entity.Property(e => e.X).HasColumnName("x");

                entity.Property(e => e.Y).HasColumnName("y");
            });

            OnModelCreatingPartial(modelBuilder);
        }

        partial void OnModelCreatingPartial(ModelBuilder modelBuilder);
    }
}

我之前自己写的

using Microsoft.EntityFrameworkCore;
using System.Diagnostics;

namespace CoreWebApi_.EF
{
    public class DigitalTwinContext : DbContext
    {

        public DigitalTwinContext() : base()
        {
            //这里可配置Context的各种配置选项
        }


        public DigitalTwinContext(DbContextOptions<DigitalTwinContext> options) : base(options)
        {
            //这里可配置Context的各种配置选项
        }


        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
        }
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            //配置数据库提供程序,并为提供程序配置对应的数据库连接字符串
            if (!optionsBuilder.IsConfigured)
            {
                String connectionStr = StaticHolder.builder.Configuration.GetConnectionString("SqlServerConnection");
                Debug.Write("isConfig =false ," + connectionStr);
                optionsBuilder.UseSqlServer(connectionStr);
            }
            else
            {
                Debug.Write("isConfig =true,");

            }


        }

    }
}

接口里面的使用

[HttpGet("AddViewFromItem")]
      public String AddViewFromItem
     (String title, String descript, String tag, int roomID,float scale,String type, float width, float height,int x, int y)
      {
          using (DigitalTwinContext db = new DigitalTwinContext())
          {
              //string name, string descript, string tag, int id, int parent
              Views view = new();
              view.parent = roomID;
              view.tag = tag;
              view.scale = scale;
              view.type = type;
              view.width = width;
              view.height = height;
              view.x = x;
              view.y = y;
              db.Add(view);
              db.SaveChanges();
              return "SUCCESS!";
          }
      }

可以看到我的和他的是有区别的，

另外脚手架定义的是是不分类partial 而且 命名全是大写开头，这将导致我直接作为model返回的json给客户端还需要处理，总感觉有点乱搞的意思。

namespace CoreWebApi_.Models
{
    public partial class Node
    {
        public string? Name { get; set; }
        public string? Descript { get; set; }
        public string? Tag { get; set; }
        public string? ItemName { get; set; }
        public string? ItemDescript { get; set; }
        public int Id { get; set; }
        public int ParentId { get; set; }
        public int? Flag { get; set; }
        public int? Parent { get; set; }
    }
}

sql创建语句

USE [DigitalTwin]
GO

/****** Object:  Table [dbo].[Views]    Script Date: 2022/9/8 15:23:57 ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE [dbo].[Views](
	[width] [float] NOT NULL,
	[height] [float] NOT NULL,
	[x] [float] NOT NULL,
	[y] [float] NOT NULL,
	[id] [int] IDENTITY(1,1) NOT NULL,
	[title] [varchar](50) NULL,
	[type] [varchar](50) NULL,
	[scale] [float] NOT NULL,
	[tag] [varchar](50) NULL,
	[data] [varchar](50) NULL,
	[parent] [int] NOT NULL,
	[parentName] [varchar](50) NULL,
	[is3d] [tinyint] NOT NULL
) ON [PRIMARY]
GO

ALTER TABLE [dbo].[Views] ADD  CONSTRAINT [DF_Views_width]  DEFAULT ((0)) FOR [width]
GO

ALTER TABLE [dbo].[Views] ADD  CONSTRAINT [DF_Views_height]  DEFAULT ((0)) FOR [height]
GO

ALTER TABLE [dbo].[Views] ADD  CONSTRAINT [DF_Views_x]  DEFAULT ((0)) FOR [x]
GO

ALTER TABLE [dbo].[Views] ADD  CONSTRAINT [DF_Views_y]  DEFAULT ((0)) FOR [y]
GO

ALTER TABLE [dbo].[Views] ADD  CONSTRAINT [DF_Views_scale]  DEFAULT ((1)) FOR [scale]
GO

ALTER TABLE [dbo].[Views] ADD  CONSTRAINT [DF_Views_parent]  DEFAULT ((0)) FOR [parent]
GO

ALTER TABLE [dbo].[Views] ADD  CONSTRAINT [DF_Views_is3d]  DEFAULT ((0)) FOR [is3d]
GO

关于主键的问题

解决办法似乎只能重新生成， 同样2个没有设置主键，有一个model 一直提示需要主键，我给他设置主键然后重新生成代码，发现区别是 没有hasNoKey()这行 hasKey("id")加上是不行的，依然错误不过错误又不一样，反正吧，efcore 第三方的东西反人类，有的大神或许认为我应该理解，我是不理解，2个一模一样的的表，我通过create语句比对了，不可能有问题， 两个都没有主键，为啥另外一个就可以插入

最后老哥说一句 ，
有问题无法解决 就直接用脚手架自己生成，解决问题。
既然要主键我就全部设置主键，
重新生成脚手架放到同一个目录

```
C:\Users\惠普\source\repos\CoreWebApi_>dotnet ef dbcontext scaffold --help


Usage: dotnet ef dbcontext scaffold [arguments] [options]

Arguments:
  <CONNECTION>  The connection string to the database.
  <PROVIDER>    The provider to use. (E.g. Microsoft.EntityFrameworkCore.SqlServer)

Options:
  -d|--data-annotations                  Use attributes to configure the model (where possible). If omitted, only the fluent API is used.
  -c|--context <NAME>                    The name of the DbContext. Defaults to the database name.
  --context-dir <PATH>                   The directory to put the DbContext file in. Paths are relative to the project directory.
  -f|--force                             Overwrite existing files.
  -o|--output-dir <PATH>                 The directory to put files in. Paths are relative to the project directory.
  --schema <SCHEMA_NAME>...              The schemas of tables to generate entity types for.
  -t|--table <TABLE_NAME>...             The tables to generate entity types for.
  --use-database-names                   Use table and column names directly from the database.
  --json                                 Show JSON output. Use with --prefix-output to parse programatically.
  -n|--namespace <NAMESPACE>             The namespace to use. Matches the directory by default.
  --context-namespace <NAMESPACE>        The namespace of the DbContext class. Matches the directory by default.
  --no-onconfiguring                     Don't generate DbContext.OnConfiguring.
  --no-pluralize                         Don't use the pluralizer.
  -p|--project <PROJECT>                 The project to use. Defaults to the current working directory.
  -s|--startup-project <PROJECT>         The startup project to use. Defaults to the current working directory.
  --framework <FRAMEWORK>                The target framework. Defaults to the first one in the project.
  --configuration <CONFIGURATION>        The configuration to use.
  --runtime <RUNTIME_IDENTIFIER>         The runtime to use.
  --msbuildprojectextensionspath <PATH>  The MSBuild project extensions path. Defaults to "obj".
  --no-build                             Don't build the project. Intended to be used when the build is up-to-date.
  -h|--help                              Show help information
  -v|--verbose                           Show verbose output.
  --no-color                             Don't colorize output.
  --prefix-output                        Prefix output with level.

最后 ，配置参数可以让首字母不大写，跟随sql字段 --use-database-names

dotnet ef dbcontext scaffold "Data Source=192.168.1.124;Initial Catalog=DigitalTwin;User ID=SA;Password=12345678;Connect Timeout=15" Microsoft.EntityFrameworkCore.SqlServer --use-database-names -f -o  Models