ASP.NET中使用Entity Framework（EF）基本操作
原创
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- 创建数据库上下文（DbContext）类：
using System.Data.Entity;
public class MyDbContext : DbContext
{
public MyDbContext() : base("MyDbContext")
{
}
public DbSet<MyEntity> MyEntities { get; set; }
}
- 创建实体类：
public class MyEntity
{
public int Id { get; set; }
public string Name { get; set; }
}
- 在Web.config中配置数据库连接字符串：
<connectionStrings>
<add name="MyDbContext" connectionString="Data Source=MyServer;Initial Catalog=MyDatabase;Integrated Security=True" providerName="System.Data.SqlClient" />
</connectionStrings>
- 添加新的数据：
using (var context = new MyDbContext())
{
var entity = new MyEntity { Name = "John" };
context.MyEntities.Add(entity);
context.SaveChanges();
}
- 查询数据：
using (var context = new MyDbContext())
{
var entities = context.MyEntities.ToList();
foreach (var entity in entities)
{
Console.WriteLine(entity.Name);
}
}
- 更新数据：
using (var context = new MyDbContext())
{
var entity = context.MyEntities.FirstOrDefault(e => e.Id == 1);
if (entity != null)
{
entity.Name = "Jane";
context.SaveChanges();
}
}
- 删除数据：
using (var context = new MyDbContext())
{
var entity = context.MyEntities.FirstOrDefault(e => e.Id == 1);
if (entity != null)
{
context.MyEntities.Remove(entity);
context.SaveChanges();
}
}
