using Demo.Data;
using Demo.Domain;
using Microsoft.EntityFrameworkCore;
using System;
using System.Linq;
namespace Demo.App
{
class Program
{
static void Main(string[] args)
{
using var context = new DemoContext();
//var italy = "Italy";
//var leagues = context.Leagues
// .Where(x=>x.Country== italy)//变量参数化查询,直接用值就不是
// .ToList();
////var leagues2 = (from lg in context.Leagues where lg.Country== "Italy" select lg).ToList();
//foreach (var league in leagues)//context.Leagues
//{
// Console.WriteLine(league.Name);
//}
//var leagues = context.Leagues
// .Where(x => x.Country.Contains("e"))// 输出 [Country] CHARINDEX(N'e', [l].[Country]) > 0
// .ToList();
////var leagues2 = (from lg in context.Leagues where lg.Country== "Italy" select lg).ToList();
//foreach (var league in leagues)//context.Leagues
//{
// Console.WriteLine(league.Name);
//}
var leagues = context.Leagues
.Where(x => EF.Functions.Like(x.Country,"%e%"))// 输出[Country] LIKE N'%e%'
.ToList();
//var leagues2 = (from lg in context.Leagues where lg.Country== "Italy" select lg).ToList();
foreach (var league in leagues)//context.Leagues
{
Console.WriteLine(league.Name);
}
//ToList()
//First() 第一个,没有会报错
//FirstOrDefault 第一个,没有返回默认值
//Single SingleOrDefault Last() LastOrDefault() 一个 最后一个必须排序,否则报错
//Count() LongCount() Min() Max() Average() Sum() 总数 Long类型总数 最大 平均 求和
//Find 寻找
//异步版本
//ToListAsync()
//...
Console.ReadKey();
}
}
}