static void Main(string[] args)
{
using (MYContext ctx = new MYContext())
{
//ctx.Database.Log = F;
ctx.Database.Log = (sql) => {
Console.WriteLine("*************Log**********" + sql);
};
/*
* Person p1 = new Person();
* p1.Age = 18;
* p1.CreateDateTime = DateTime.Now;
* p1.Name = "EF";
* ctx.Persons.Add(p1);*/
/*
* Dog d = new Dog();
* d.Name = "旺财";
* //ctx.Dogs.Add(d);
* ctx.Set<Dog>().Add(d);
* Console.WriteLine("Id="+d.Id);
* ctx.SaveChanges();
* Console.WriteLine("Id=" + d.Id);*/
// IQueryable<Person> persons = ctx.Persons.Where(p=>p.Age>10);
//var persons = ctx.Persons.Where(p=>p.Age>10);
/*
* var persons = from p in ctx.Persons
* where p.Age > 10
* select p;
* foreach(var p in persons)
* {
* Console.WriteLine(p);
* }*/
//var person = ctx.Persons.Where(p => p.Id == 4).SingleOrDefault();
/*
* var person = ctx.Persons.SingleOrDefault(p=>p.Id==4);
* if(person==null)
* {
* Console.WriteLine("已被删除");
* }
* else
* {
* ctx.Persons.Remove(person);
* ctx.SaveChanges();
* }*/
/*
* ctx.Persons.RemoveRange(ctx.Persons.Where(p => p.Age > 10));
* ctx.SaveChanges();*/
/*
* var persons = ctx.Persons;
* foreach(var p in persons)
* {
* p.Age++;
* }
* ctx.SaveChanges();*/
/*
* var items = from p in ctx.Persons
* group p by p.Age into g1
* select new { Age = g1.Key, Count = g1.Count(), IdMax = g1.Max(p => p.Id) };
* foreach(var item in items)
* {
* Console.WriteLine(item.Age+"="+item.Count+","+item.IdMax);
* }*/
/*
* var items = from p in ctx.Persons
* orderby p.Age
* select p;
* foreach(var p in items)
* {
* Console.WriteLine(p);
* }*/
// var items = ctx.Persons.OrderBy(p=>p.Age).Skip(1).Take(2);
/*
* var items = (from p in ctx.Persons
* orderby p.Age
* select p).Skip(1).Take(2);//.ToList();
*
* Console.WriteLine("准备开始foreach喽！！！！！！！！！");
* foreach (var p in items)
* {
* Console.WriteLine(p);
* }*/
/*
* Person p = ctx.Persons.First();
* p.Name = "rrr";
* p.Age = 666;
* ctx.SaveChanges();*/
//long[] ids = { 2, 5, 6 };//不要写成int[]
// var result = ctx.Persons.Where(p => ids.Contains(p.Id));
//必须写成IQueryable<Person>，如果写成IEnumerable就会在内存中取后续数据
/*
* IQueryable<Person> result = ctx.Persons.Where(p=>p.Id>3);
* result = result.Where(p=>p.Name.Length>3);
*
* result.ToList();*/
/*
* string name = Console.ReadLine();
* int age = 888;
* ctx.Database.ExecuteSqlCommand("insert into T_Persons(Name,CreateDateTime,Age) values({0},GetDate(),{1})", name, age);*/
/*
* var result = ctx.Database.SqlQuery<GroupCount>("select age,count(*) AgeCount from T_Persons group by Age");
* foreach(GroupCount item in result)
* {
* Console.WriteLine(item.Age+"="+item.AgeCount);
* }*/
/*
* var result = ctx.Database.SqlQuery<Person>("select * from T_Persons");
* foreach(var p in result)
* {
* Console.WriteLine(p);
* }*/
/*
* var result = ctx.Database.SqlQuery<string>("select Name from T_Persons");
* foreach(string item in result)
* {
* Console.WriteLine(item);
* }*/
/*
* int i = ctx.Database.SqlQuery<int>("select count(*) from T_Persons").Single();
* Console.WriteLine(i);*/
// var result = ctx.Persons.Where(p=>SqlFunctions.DateDiff("hour",p.CreateDateTime,DateTime.Now)>1);
//var result = ctx.Persons.Where(p => (DateTime.Now - p.CreateDateTime).TotalHours > 1);
//var result = ctx.Persons.Where(p => p.Id==3);
//var result = ctx.Persons.Where(p => Convert.ToString(p.Id) == "3");
//result.ToList();
// Person p1 = ctx.Persons.SingleOrDefault(p => p.Id == 1);
/*
* Person p1 = new Person() {Id=1,Age=666,CreateDateTime=DateTime.Parse("2017-03-14 16:38:25.417"),Name="rrr" };
* ctx.Persons.Remove(p1);
* //p1.Age++;
* ctx.SaveChanges();*/
/*
* Person p1 = new Person() { Age=119,
* CreateDateTime =DateTime.Now,Name="hj"};
* Console.WriteLine(ctx.Entry(p1).State);
* //ctx.Entry(p1).State = System.Data.Entity.EntityState.Added;
* ctx.Persons.Add(p1);
* Console.WriteLine(ctx.Entry(p1).State);
*
* ctx.SaveChanges();
* Console.WriteLine(ctx.Entry(p1).State);*/
/*
* Person p1 = new Person { Id=1};
* Console.WriteLine(ctx.Entry(p1).State);
* ctx.Persons.Attach(p1);
* Console.WriteLine(ctx.Entry(p1).State);
* p1.Name = "rupeng.com";
* Console.WriteLine(ctx.Entry(p1).State);
* ctx.SaveChanges();
* Console.WriteLine(ctx.Entry(p1).State);*/
/*
* Person p1 = ctx.Persons.First();
* Console.WriteLine(ctx.Entry(p1).State);
* p1.Age = 111;
* Console.WriteLine(ctx.Entry(p1).State);
* ctx.SaveChanges();
* Console.WriteLine(ctx.Entry(p1).State);
*/
/*
* Person p1 = ctx.Persons.First();
* Console.WriteLine(ctx.Entry(p1).State);
* //ctx.Persons.Remove(p1);
* ctx.Entry(p1).State = System.Data.Entity.EntityState.Deleted;
* Console.WriteLine(ctx.Entry(p1).State);
* ctx.SaveChanges();
* Console.WriteLine(ctx.Entry(p1).State);
*
* //ctx.Persons.Add(p1);
* ctx.Entry(p1).State = System.Data.Entity.EntityState.Added;
* ctx.SaveChanges();
* Console.WriteLine(ctx.Entry(p1).State);
*/
/*
* Person p1 = new Person();
* p1.Id = 6;
* p1.Name = "如鹏网";
* Console.WriteLine(ctx.Entry(p1).State);
* ctx.Persons.Attach(p1);
* Console.WriteLine(ctx.Entry(p1).State);
* ctx.Entry(p1).Property(e => e.Name).IsModified = true;
* Console.WriteLine(ctx.Entry(p1).State);
* ctx.SaveChanges();
* Console.WriteLine(ctx.Entry(p1).State);*/
/*
* foreach(var p in ctx.Persons.AsNoTracking().Where(p=>p.Id>5))
* {
*
* p.Age++;
* Console.WriteLine(p);
* }*/
var p = ctx.Persons.AsNoTracking().First();
Console.WriteLine(ctx.Entry(p).State);
ctx.Entry(p).State = System.Data.Entity.EntityState.Unchanged;
p.Name = "哈哈哈哈";
Console.WriteLine(ctx.Entry(p).State);
ctx.SaveChanges();
Console.ReadKey();
}
}
static void Main(string[] args)
{
using (MYContext ctx = new MYContext())
{
/*
* Person p1 = new Person();
* p1.Age = 18;
* p1.CreateDateTime = DateTime.Now;
* p1.Name = "EF";
* ctx.Persons.Add(p1);*/
/*
* Dog d = new Dog();
* d.Name = "旺财";
* //ctx.Dogs.Add(d);
* ctx.Set<Dog>().Add(d);
* Console.WriteLine("Id="+d.Id);
* ctx.SaveChanges();
* Console.WriteLine("Id=" + d.Id);*/
// IQueryable<Person> persons = ctx.Persons.Where(p=>p.Age>10);
//var persons = ctx.Persons.Where(p=>p.Age>10);
/*
* var persons = from p in ctx.Persons
* where p.Age > 10
* select p;
* foreach(var p in persons)
* {
* Console.WriteLine(p);
* }*/
//var person = ctx.Persons.Where(p => p.Id == 4).SingleOrDefault();
/*
* var person = ctx.Persons.SingleOrDefault(p=>p.Id==4);
* if(person==null)
* {
* Console.WriteLine("已被删除");
* }
* else
* {
* ctx.Persons.Remove(person);
* ctx.SaveChanges();
* }*/
/*
* ctx.Persons.RemoveRange(ctx.Persons.Where(p => p.Age > 10));
* ctx.SaveChanges();*/
/*
* var persons = ctx.Persons;
* foreach(var p in persons)
* {
* p.Age++;
* }
* ctx.SaveChanges();*/
/*
* var items = from p in ctx.Persons
* group p by p.Age into g1
* select new { Age = g1.Key, Count = g1.Count(), IdMax = g1.Max(p => p.Id) };
* foreach(var item in items)
* {
* Console.WriteLine(item.Age+"="+item.Count+","+item.IdMax);
* }*/
/*
* var items = from p in ctx.Persons
* orderby p.Age
* select p;
* foreach(var p in items)
* {
* Console.WriteLine(p);
* }*/
// var items = ctx.Persons.OrderBy(p=>p.Age).Skip(1).Take(2);
var items = (from p in ctx.Persons
orderby p.Age
select p).Skip(1).Take(2);
foreach (var p in items)
{
Console.WriteLine(p);
}
Console.ReadKey();
}
}
