Select top 1操作简化: 在Linq中,使用Select操作可以选择指定的字段,使用Take操作可以选择指定数量的记录。为了简化Select top 1操作,可以使用FirstOrDefault方法,该方法接受一个Lambda表达式作为参数,用于指定选择的条件。例如: 代码语言:csharp 复制 var topRecord = data.FirstOrDefault(x => x.Category =...
SELECTTOP1*FROMCustomersORDERBYNEWID() --随机取出一条记录,想取多条,则top n 当随着LINQ时代的来代,这一切就有点不太好用了 按照传统的思路,我们可以把LINQ查询式写为 var results=(from cindb.Customers orderbyNEWID() select c).Take(10); //具体数据条数由take来进行指定 问题出现了,在C#当中根本...
View Code 上述是简单查询方法,这里SELECT于sql中的Select没什么区别,只是位置变了,代表查询所有值 条件关系型查询方法: + View Code 条件关系型查询就是在简单查询的基础上加上条件关系操作符 && ,|| First()单一查询 First()查询类似于sql语句中的TOP(1),限定查询,只向我们返回第一个元素 例如: //返回执行...
db.S.Where(q=>q.TypeID==1).OrderByDesending(q=>q.ID).Take(1);
DataClasses1DataContext db = new DataClasses1DataContext();var s = (from p in db.BusinessWaybill orderby p.id descending select p.id).First();texts.Append(s..ToString());
SELECT TOP 1 * FROM table ORDER BY col DESC All replies (12) Thursday, January 10, 2008 8:28 AM ✅Answered x_coloredcode NorthwindDataContext db = new NorthwindDataContext(); var shippers = from shipper in db.Shippers orderby shipper.CompanyName select shipper; return shippers.First(); ...
SELECT TOP 1 [t0].[CustomerID], [t0].[CompanyName], FROM [Customers] AS [t0] WHERE (NOT (EXISTS( SELECT NULL AS [EMPTY] FROM ( SELECT TOP 1 [t1].[CustomerID] FROM [Customers] AS [t1] WHERE [t1].[City] = @p0 ORDER BY [t1].[CustomerID] ...
成功linq Take实现top用法1 using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.UI;using System.Web.UI.WebControls;using System.Data;namespace WebApplication1.linq1.top1{ public partial class test1 : System.Web.UI.Page { protected void Page_Load(...
SELECT TOP 1 [t0].[CustomerID], [t0].[CompanyName], FROM [Customers] AS [t0] WHERE (NOT (EXISTS( SELECT NULL AS [EMPTY] FROM ( SELECT TOP 1 [t1].[CustomerID] FROM [Customers] AS [t1] WHERE [t1].[City] = @p0 ORDER BY [t1].[CustomerID] ) AS [t2] WHERE [t0].[Custo...
select r).FirstOrDefault(); //()linq to ef 好像不支持 Last() var ss1 = db.Am_recProScheme.FirstOrDefault(); //var ss1 = db.Am_recProScheme.First(); string sssql = "select top(1) * from Am_recProScheme"; 6.跳过前面多少条数据取余下的数据 ...