在跨平台开发中使用Sqlite EF 框架
1. 安装依赖包
install-package Microsoft.EntityFrameworkCore
install-package EntityFrameworkCore.Sqlite
install-package Microsoft.EntityFrameworkCore.Sqlite.Design
install-package Microsoft.EntityFrameworkCore.Tools
2.建立数据模型
using System.ComponentModel.DataAnnotations;
namespace EFCoreQuickStart.Models
{public class Book{[Key]public int BookId { get; set; }public string Text { get; set; }}
}
3.建立数据上下文
using Microsoft.EntityFrameworkCore;namespace EFCoreQuickStart.Models
{public class BookDbContext : DbContext{public DbSet<Book> Books { get; set; }protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder){optionsBuilder.UseSqlite("Data Source=books.db");}}
}
4.迁移数据
(系统不会自动生成数据库，因此需要通过迁移命令来创建数据库文件)
Add-Migration InitalCreate
Update-Database
5.使用
using EFCoreQuickStart.Models;
using Microsoft.EntityFrameworkCore;namespace EFCoreQuickStart
{internal class Program{static void Main(string[] args){Console.WriteLine("Hello, World!");using (var db = new BookDbContext()) {Console.WriteLine("插入一条记录");db.Books.Add(new Book() { Text = "C#高级编程" } );Console.WriteLine("成功插入一条记录");try {db.SaveChanges();}catch (DbUpdateException ex){Console.WriteLine(ex.InnerException?.Message);}//查询Console.WriteLine("查询所有记录");var model = db.Books.OrderBy(b => b.BookId).First();Console.WriteLine(model.Text);//更新Console.WriteLine("更新一条记录");model.Text = "C#高级编程（第10版）";db.SaveChanges();Console.WriteLine("更新成功！");}}}
}