//3.1 异步查询对象列表
static async Task <IEnumerable <Donator> > GetDonatorsAsync()
{
using (var db = new DonatorsContext())
{
return(await db.Donators.ToListAsync());
}
}
//3.3 异步定位一条记录
static async Task <Donator> FindDonatorAsync(int donatorId)
{
using (var db = new DonatorsContext())
{
return(await db.Donators.FindAsync(donatorId));
}
}
static void Main(string[] args)
{
#region 1.0 视图
Database.SetInitializer(new Initializer());
using (var db = new DonatorsContext())
{
//1.1 方法一
//var donators = db.DonatorViews;
//foreach (var donator in donators)
//{
// Console.WriteLine(donator.ProvinceName + "\t" + donator.DonatorId + "\t" + donator.DonatorName + "\t" + donator.Amount + "\t" + donator.DonateDate);
//}
//1.2 另一种方法
var sql = @"SELECT DonatorId ,DonatorName ,Amount ,DonateDate ,ProvinceName from dbo.DonatorViews where ProvinceName={0}";
var donatorsViaCommand = db.Database.SqlQuery <DonatorViewInfo>(sql, "河北省");
foreach (var donator in donatorsViaCommand)
{
Console.WriteLine(donator.ProvinceName + "\t" + donator.DonatorId + "\t" + donator.DonatorName + "\t" + donator.Amount + "\t" + donator.DonateDate);
}
}
#endregion
#region 2.0 EF调用存储过程查询数据SqlQuery
//using (var db=new DonatorsContext())
//{
// var sql = "SelectDonators {0}";
// var donators = db.Database.SqlQuery<DonatorFromStoreProcedure>(sql,"山东省");
// foreach (var donator in donators)
// {
// Console.WriteLine(donator.ProvinceName+"\t"+donator.Name+"\t"+donator.Amount+"\t"+donator.DonateDate);
// }
//}
//2.1 EF调用存储过程之ExecuteSqlCommand方法
using (var db = new DonatorsContext())
{
//var sql = "UpdateDonator {0},{1}";
//Console.WriteLine("执行存储过程前的数据为：");
//PrintDonators();
//var rowsAffected = db.Database.ExecuteSqlCommand(sql, "Update", 10m);
//Console.WriteLine("影响的行数为{0}条", rowsAffected);
//Console.WriteLine("执行存储过程之后的数据为：");
//PrintDonators();
}
#endregion
#region 3.0 异步API
//Console.WriteLine(FindDonatorAsync(1).Result.DonateDate);
#endregion
Console.WriteLine("Operation Completed!");
Console.ReadLine();
}
//3.4 异步聚合函数
static async Task <int> GetDonatorCountAsync()
{
using (var db = new DonatorsContext())
{
return(await db.Donators.CountAsync());
}
}
//3.2 异步创建一个新的对象
static async Task InsertDonatorAsync(Donator donator)
{
using (var db = new DonatorsContext())
{
db.Donators.Add(donator);
await db.SaveChangesAsync();
}
}
//3.5 异步遍历查询结果
static async Task LoopDonatorsAsync()
{
using (var db = new DonatorsContext())
{
await db.Donators.ForEachAsync(d =>
{
d.DonateDate = DateTime.Today;
});
}
}
static void PrintDonators()
{
using (var db = new DonatorsContext())
{
var donators = db.Donators.Where(p => p.ProvinceId == 2);//找出河北省的打赏者
foreach (var donator in donators)
{
Console.WriteLine(donator.Name + "\t" + donator.Amount + "\t" + donator.DonateDate);
}
}
}
