如何从sql查询中编写Linq查询或lambda表达式 [英] how to write Linq query or lambda expresion from sql query

问题描述

大家好，

i想写这个SQL查询的linq查询或lambda expresion

 选择最大（tblEmailList.name），计数（tblEmailRecipientList.ListId）<跨度类= 代码关键字 >从 tblEmailList <跨度类= 代码关键字>加入 tblEmailRecipientList <跨度类= 代码关键字>上 tblEmailRecipientList.ListId = tblEmailList.ListId 
 <跨度类= 代码关键字>基 <跨度类=代码 - 关键字> by  tblEmailRecipientList.ListId 

提前感谢

解决方案

尝试如下：

  var  result = 来自 p   context.tblEmailRecipientList 
  join  c  in  context.tblEmailList等于c.ListId 
  group  p by p.ListId  into  temp 
  select   new  
 {
 TotalCount = temp.Count（），
 MaxName = temp.Max（m = >  m.name）
}; 

从这里开始：如何：执行分组连接（C＃编程指南） [ ^ ]

请你在卡住时回到这里。



详情请见：

查询表达式语法示例：加入运算符 [ ^ ]

查询表达式语法示例：分组 [ ^ ]

如何：用C＃编写LINQ查询 [ ^ ]

101 LINQ样本 [ ^ ]

LINQ查询表达式（ C＃编程指南） [ ^

Hi All,
i want to write linq query or lambda expresion fot this sql query

select Max(tblEmailList.name),count(tblEmailRecipientList.ListId) from tblEmailList  join tblEmailRecipientList on tblEmailRecipientList.ListId = tblEmailList.ListId
group by tblEmailRecipientList.ListId

thanks in advance

解决方案

Try like below:

var result = from p in context.tblEmailRecipientList             
 join c in context.tblEmailList on p.ListId equals c.ListId  
 group p by p.ListId into temp 
 select new 
 {
       TotalCount = temp.Count(), 
       MaxName = temp.Max(m => m.name)
 };

Start here: How to: Perform Grouped Joins (C# Programming Guide)[^]
Please, come back here when you get stuck.

For further details, please see:
Query Expression Syntax Examples: Join Operators[^]
Query Expression Syntax Examples: Grouping[^]
How to: Write LINQ Queries in C#[^]
101 LINQ Samples[^]
LINQ Query Expressions (C# Programming Guide)[^]

这篇关于如何从sql查询中编写Linq查询或lambda表达式的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！