C#-efcore-增删改查代码

以下是C# EFCore的增删改查代码：

增加：

using (var context = new MyDbContext())
{
    var newPerson = new Person
    {
        FirstName = "John",
        LastName = "Doe",
        Age = 30
    };

    context.Persons.Add(newPerson);
    context.SaveChanges();
}

删除：

using (var context = new MyDbContext())
{
    var personToDelete = context.Persons.Where(p => p.Id == 1).FirstOrDefault();

    if (personToDelete != null)
    {
        context.Persons.Remove(personToDelete);
        context.SaveChanges();
    }
}

修改：

using (var context = new MyDbContext())
{
    var personToUpdate = context.Persons.Where(p => p.Id == 1).FirstOrDefault();

    if (personToUpdate != null)
    {
        personToUpdate.FirstName = "Jane";
        personToUpdate.LastName = "Doe";
        personToUpdate.Age = 35;

        context.SaveChanges();
    }
}

查询：

using (var context = new MyDbContext())
{
    var persons = context.Persons.ToList();

    foreach (var person in persons)
    {
        Console.WriteLine($"{person.FirstName} {person.LastName}, Age: {person.Age}");
    }
}