.net core 2.2 控制台ef使用sqlite存储数据

1.安装依赖

Microsoft.EntityFrameworkCore.Design

Microsoft.EntityFrameworkCore.Sqlite

Microsoft.EntityFrameworkCore.Tools

Microsoft.Extensions.Configuration

Microsoft.Extensions.Configuration.Json

2.添加appsettings.json（DB路径使用了绝对路径）

{
  "exclude": [
    "**/bin",
    "**/bower_components",
    "**/jspm_packages",
    "**/node_modules",
    "**/obj",
    "**/platforms"
  ],
  "ConnectionStrings": {
    "db": "Data Source=C:\Users\lixipeng\source\repos\ConsoleApp1\ConsoleApp4\db/blogging.db"
  }
}

3.使用CodeFirst

3.1 新建Models文件夹

3.2新建Blog类

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

namespace Sqlite.Models
{
    public class Blog
    {
        public int BlogId { get; set; }
        public string Url { get; set; }

        public ICollection<Post> Posts { get; set; }
    }
}

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3.3新建Post类

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

namespace Sqlite.Models
{
    public class Post
    {
        public int PostId { get; set; }
        public string Title { get; set; }
        public string Content { get; set; }
        public int BlogId { get; set; }
        public Blog Blog { get; set; }
    }
}

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3.4新建数据库上下文

using JetBrains.Annotations;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;

namespace Sqlite.Models
{
    public class BloggingContext:DbContext
    {
        public DbSet<Post> Posts { get; set; }
        public DbSet<Blog> Blogs { get; set; }
        private IConfiguration configuration;
        public BloggingContext()
        {
            configuration = new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory()).AddJsonFile("appsettings.json").Build();
        }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseSqlite(configuration.GetConnectionString("db"));
        }
    }
}

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4新建db文件夹

5生成数据库（用命令生成失败了，不知是不是我环境的问题，改用了代码生成数据库（生成数据库后应该需要注释掉）），运行代码后会在设置的文件夹中生成db文件

using Sqlite.Models;
using System;
using System.Linq;

namespace ConsoleApp4
{
    class Program
    {
        static void Main(string[] args)
        {
            using (BloggingContext db = new BloggingContext())
            {
                db.Database.EnsureCreated();//这句代码会创建数据库，需要注意数据库路径
            } 
        }
    }
}

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6插入数据保存和查询测试

using Sqlite.Models;
using System;
using System.Linq;

namespace ConsoleApp4
{
    class Program
    {
        static void Main(string[] args)
        {
            using (BloggingContext db = new BloggingContext())
            {
                db.Database.EnsureCreated(); //这句代码会创建数据库，需要注意数据库路径（创建后自己记得注释）
                db.Blogs.Add(new Blog { Url = "https://blog.csdn.net/lms99251" });
                var count = db.SaveChanges();
                var fir = db.Blogs.ToList();
                Console.WriteLine(db.Blogs.FirstOrDefault().BlogId);
            }
        }
    }
}

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