IQueryable与IEnumberable的区别

var set3 = (from c in db.cms_certificateDetails select c).OrderByDescending(c => c.id).AsEnumerable()
 .Skip(150).Take(10);
 foreach (var cmsCertificateDetailse in set3)
 ...{
 Console.WriteLine(cmsCertificateDetailse.czry + ";" + cmsCertificateDetailse.kddh + "\\r\\n");//打印结果
}

		

SELECT 
[Extent1].[id] AS [id], 
[Extent1].[kddh] AS [kddh], 
[Extent1].[czry] AS [czry], 
[Extent1].[yjnr] AS [yjnr], 
[Extent1].[tjTime] AS [tjTime], 
[Extent1].[bz] AS [bz], 
[Extent1].[forId] AS [forId]
FROM [dbo].[cms_certificateDetails] AS [Extent1]
ORDER BY [Extent1].[id] DESC

		

var set4 = (from c in db.cms_certificateDetails select c).OrderByDescending(c => c.id).AsQueryable()
 .Skip(150).Take(10);
 foreach (var cmsCertificateDetailse in set4)
 ...{
 Console.WriteLine(cmsCertificateDetailse.czry + ";" + cmsCertificateDetailse.kddh + "\\r\\n");//打印结果
}

		

SELECT TOP (10) 
[Extent1].[id] AS [id], 
[Extent1].[kddh] AS [kddh], 
[Extent1].[czry] AS [czry], 
[Extent1].[yjnr] AS [yjnr], 
[Extent1].[tjTime] AS [tjTime], 
[Extent1].[bz] AS [bz], 
[Extent1].[forId] AS [forId]
FROM ( SELECT [Extent1].[id] AS [id], [Extent1].[kddh] AS [kddh], [Extent1].[czry] AS [czry], [Extent1].[yjnr] AS [yjnr], [Extent1].[tjTime] AS [tjTime], [Extent1].[bz] AS [bz], [Extent1].[forId] AS [forId], row_number() OVER (ORDER BY [Extent1].[id] DESC) AS [row_number]
    FROM [dbo].[cms_certificateDetails] AS [Extent1]
) AS [Extent1]
WHERE [Extent1].[row_number] > 150
ORDER BY [Extent1].[id] DESC

		

static void Main(string[] args)
        ...{
            //创建数据库访问网关
            using (SchoolDBEntities schoolEntities = new SchoolDBEntities())
            ...{
                //查询的结果放入IQueryable接口的集合中
                IQueryable<T_Class> classesIQue = (from c in schoolEntities.T_Class
                                                   orderby c.ID
                                                     select c).Skip<T_Class>(3).Take<T_Class>(3);
                //注意这个AsEnumerable<T_Class>()在分页查询之前，先将其转换成IEnumerable类型
                IEnumerable<T_Class> classesIEnu = (from c in schoolEntities.T_Class
                                                    orderby c.ID   
                                                    select c).AsEnumerable<T_Class>().Skip<T_Class>(3).Take<T_Class>(3);
                //因为启用了延迟加载机制，所以下面调用一下，才会真正去读取数据库
                int i = 0;
                foreach (var c in classesIQue)
                ...{
                    i++;
                }
                Console.WriteLine(i);
                foreach (var c in classesIEnu)
                ...{
                    i++;
                }
                Console.WriteLine(i);
            }
            Console.WriteLine("OK");
            Console.ReadKey();
        }