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Start/Stop RDS Instances on Schedule

by Ivan Perevernykhata

How to start/stop RDS instances on schedule with aws-sdk, nodeJs Lambda function and CloudWatch

functionExtensions Techniques 1: Throwable Functional Interfaces

by JIANGWilliam

This is the first of three episodes to introduce considerations and techniques used for the throwable functional interfaces defined in my open-sourced library functionExtensions.

Dynamically creating a predicate delegate

by Randy Kroeger

Created a POC that dynamically builds a predicate using Expression and Reflection.

Northwind Database with NoSQL DBreeze

by Pradip Koli

Using NoSQL DBreeze database with ASP.NET on SQL Northwind Database.

Latest Articles

Working with AWS Lambda C++ Runtime as Lambda layer

by P. Erward

How to put the AWS Lambda C++ Runtime into a Lambda layer and how to use it

Five Minute Cloud Lamdba Function

by egoebelbecker

Create an AWS Lambda in five minutes

How to Access Private S3 Objects with AWS Cognito

by Necmettin Demir

To provide a URL link to access objects in private S3 bucket through AWS Cognito User Pool (using hosted UI), Authorized API Gateway and Lambda in a Secure Way.

Running PHP in Lambda on a Homebrew MVC Framework

by PaulKukiel

Build a Custom PHP MVC in 30 mins and deploy to AWS lambda

All Articles

Lambda

Working with AWS Lambda C++ Runtime as Lambda layer

21 Feb 2024 by P. Erward

How to put the AWS Lambda C++ Runtime into a Lambda layer and how to use it

How do I use AJAX in an AWS lambda/serverless website

23 Nov 2023 by Mike Breeden

In the past I've been able to be very creative using AJAX in ASP.Net websites, particularly for Intranet Applications. I've been exploring AWS Lambda/Serverless websites which have a great cost advantage, etc. Apparently you cannot use AJAX...

An unhandled exception occurred while processing the request AWS lambda project

23 Feb 2023 by Hasitha Wijesooriya

I am trying to run my lambda project in Asp.net Core. I attempted several solutions but received the same error. FileNotFoundException: Could not load file or assembly 'File Processing, Culture=neutral, PublicKeyToken=null'. The system cannot...

Five Minute Cloud Lamdba Function

2 Oct 2022 by egoebelbecker

Create an AWS Lambda in five minutes

How do I take a response HTTP with AWS lambda?

9 Jun 2022 by Giuseppe Di Palma

I wrote a telegram bot with aws lambda. I have an Api gateway endpoint which runs the event and triggers the lambda function. Now the problem is that I can't get the "body" because it always returns the same error. This is the request I can get...

How to Access Private S3 Objects with AWS Cognito

21 May 2022 by Necmettin Demir

To provide a URL link to access objects in private S3 bucket through AWS Cognito User Pool (using hosted UI), Authorized API Gateway and Lambda in a Secure Way.

How do group by and count in lambda expression

14 Mar 2022 by HRVP

I have one model MaterialModel ID Material 1 MaterialZZZ 2 MaterialYYY 3 MaterialXXX 1 MaterialABC 2 MaterialKKK 2 MaterialVVV 5 MaterialMMM Expected Result (Result Model) ID Count 1 2 2 3 3 1 5 1 I want to group by and take the...

How do group by and count in lambda expression

14 Mar 2022 by Maciej Los

Take a look at below code: void Main() { List mm = new List() { new MaterialModel(){ID = 1, Material = "MaterialZZZ"}, new MaterialModel(){ID = 2, Material = "MaterialYYY"}, new MaterialModel(){ID = 3,...

How do group by and count in lambda expression

14 Mar 2022 by Luc Pattyn

static void Main(string[] args) { List items=new List(); items.Add(new Item(1, "zzz")); items.Add(new Item(2, "yyy")); items.Add(new Item(3, "xxx")); items.Add(new Item(1, "abc")); items.Add(new Item(2, "kkk"));...

What I'm missing while converting my Python code to AWS lambda?

6 Nov 2021 by Richard MacCutchan

You already posted this question at Can anyone convert this Python flask code into AWS lambda?[^], and I explained what the problem is. Please do not repost.

Can anyone convert this Python flask code into AWS lambda?

6 Nov 2021 by Richard MacCutchan

Sorry no. This site does not provide free code conversion services.

How can I avoid null using lambda in this case?

20 Oct 2021 by User 15041314

{ "message": "The operation was successful.", "code": 200, "fileDetailResponseDtos": [ { "phoneNumber": "550000000", "textMessage": "Message1", "createDateTime": "2021-10-20T15:45:27.277", "sender": "Anar", ...

How to handle optional condition / null in single statement of lambda expression

24 Jun 2021 by bholey

var deleteItems = _EFContext.DbTable.Where(so => so.Identifier == ProviderIdentifier && !string.IsNullOrEmpty(tranType) ? so.TranType.ToLower() == tranType : **true**); _EFContext.DbTable.RemoveRange(deleteItems);...

How to handle optional condition / null in single statement of lambda expression

24 Jun 2021 by Richard Deeming

Trying to push the condition to the database query will result in poor performance. Instead, only add the condition if it is required: var deleteItems = _EFContext.DbTable.Where(so => so.Identifier == ProviderIdentifier); if...

Running PHP in Lambda on a Homebrew MVC Framework

14 Jun 2021 by PaulKukiel

Build a Custom PHP MVC in 30 mins and deploy to AWS lambda

How to Easily Create Telegram Bot using C#

23 May 2021 by Uladzislau Baryshchyk

A walkthrough and source code for creating telegram bot using C# and deploying it on AWS

How to solve the problem in lambda function

10 Mar 2021 by RupaT

I am have a lambda function which calls an API and return the data to react where the react prints it in the front end. When I call an API(1) it is working , but for another API its not working. Can someone please help me resolve this? Lambda...

Deploy a Typescript Lambda Function with AWS CDK and a Deno Layer

24 Nov 2020 by PaulKukiel

How to build and deploy a Typescript lambda function with AWS CDK and Deno layer

Mocking Expressions

8 Aug 2020 by Vlad Neculai Vizitiu

Mocking/stubbing lambda expressions to have a bit more control over our unit tests

Lambda group by query with count in mvc5 C#

6 Aug 2020 by AramRezaie

I am writing lambda query to get some details from table. I want to get count of each same records with 'UserID' and 'AssetId'. My table structure is as follows. UserID AssetID ProductName ProductLocate...

Lambda group by query with count in mvc5 C#

6 Aug 2020 by F-ES Sitecore

LINQ Count[^]

Dynamically Build LINQ Expressions

3 Jun 2020 by Jeremy Likness

A primer on using LINQ to wring strongly typed queries directly in code

entity-framework

How to join three table lambda expression in C#?

2 Jun 2020 by Maciej Los

Start here: Perform inner joins (LINQ in C#) | Microsoft Docs[^] Perform left outer joins (LINQ in C#) | Microsoft Docs[^] When you get stuck, come back here, provide your code, describe your issue and wait for response.

How to join three table lambda expression in C#?

2 Jun 2020 by Member 14169626

How to join three table. I want to select the department id column from the department table of the person.If I want to select the status id from the staff table according to those personid and departmentid. I want to select columns from...

How to group by having lambda expression in C#?

28 May 2020 by Maciej Los

Try: var result = Myentity.Person .Where(x=>x.per==123) .GroupBy(x=>new {x.a, x.b}) .Select(grp=> grp.OrderByDescending(x=> x.d).First()) .ToList();

entity-framework

How to group by having lambda expression in C#?

27 May 2020 by Member 14169626

Select id from table person where per=123 group by a,b having count(*)=max(d) Myentity.Person.where(x=>x.per=123).GroupBy(x=>new {x.a,x.b}) What I have tried: How to lambda expression this query.

entity-framework

How to group by having lambda expression in C#?

27 May 2020 by Richard MacCutchan

Lambda expressions - C# Programming Guide | Microsoft Docs[^]

entity-framework

Translating C# Lambda Expressions to General Purpose Filter Descriptors & HTTP Query Strings

22 May 2020 by Kamran Saeedi

An idea on how to use .NET ExpressionVisitor to translate lambda expressions into classes that encapsulate data suitable for filtering data & creating query strings

Expression-Trees

How can I use where instead of contains?

16 May 2020 by phil.o

These are not the same thing. Where expects a predicate as argument which is used to filter the items in a collection, and returns a filtered enumeration. Contains expects an item as argument and returns true or false depending on whether the...

entity-framework

How can I use where instead of contains?

16 May 2020 by Member 14169626

In terms of performance, I want to do using contains instead of where. How can I create the query below without using contains? var t=myentities.Employee.WHERE(x=>x.EmployeeID ==123 && myList.Any(y=>x.BranchID.Contains)).ToList(); What I have...

entity-framework

Linq and lambda expression

27 Apr 2020 by Fernando_Costa

Now work. var myvar = Model.Where(_ => _.Status== (int)Status.Yes) .Where(_ => _.Status== (int)Status.No) .OrderByDescending(_ => _.Agenda.Dt).FirstOrDefault();

How to restrict few linq features/ lampda query for my C# collection

29 Mar 2020 by Maciej Los

Seems, you don't understand what OriginalGriff has already told you... So, i'll try to show you an example. Imagine, you have a Person class: public class Person { private string personname = string.Empty; private DateTime dob = new...

How to restrict few linq features/ lampda query for my C# collection

29 Mar 2020 by code4Better

Hello All, I have a C# collection; say personal info, List _personalInfo = new List(); Currently I can perform any action on these collection using linq/lamda like _personalInfo.Where or personalInfo.Count or...

How to restrict few linq features/ lampda query for my C# collection

28 Mar 2020 by OriginalGriff

The best way to do that is encapsulation: make the List a private member of a class of your own, and create methods to allow users to do "permitted" actions. At no time does the encapsulating class return the encapsulated collection to the...

Using the AWS Toolkit for PyCharm to Create and Deploy a Kinesis Firehose Stream with a Lambda Transformation Function.

7 Mar 2020 by James A. Brannan

Semi-realistic example of using AWS Kinesis Firehose

Sending Data to Kinesis Firehose Using Python

7 Mar 2020 by James A. Brannan

In this tutorial, you create a simple Python client that sends records to an AWS Kinesis Firehose stream.

Putting the Fun in C# Local Functions

2 Mar 2020 by Rion Williams

C# local functions and how they can be used to make code more readable

Using LambdaBiz Framework to Orchestrate AWS Lambda

1 Mar 2020 by JUST_Neeraj

Create long-running, stateful, durable and serverless orchestrations in AWS using the LambdaBiz framework

Automapper 3.2.1 The Call is Ambiguous Between the Following Methods or Properties

12 Feb 2020 by OwenDavies

A fix for people experiencing the same issue with AutoMapper 3.2.1

How to merge(contains) two table values using query with linq in C#?

12 Jan 2020 by Maciej Los

I already answered your question here: How to write lambda linq query in C#?[^] Please, respect the rules of QA forum[^] and do not repost questions!

How to merge(contains) two table values using query with linq in C#?

12 Jan 2020 by Member 14169626

var query1=entities.Table1.Where(x=>x.TypeID=="4").Select(x=>x.ID).ToList(); var query2=entities.Table2.Where(x=>x.PID==2)Select(x=>x.ID).ToList(); I'm pulling the same fields from two different tables. The 2nd query retrieves the first query value. What I have tried: var...

How to merge(contains) two table values using query with linq in C#?

11 Jan 2020 by Gerry Schmitz

query2.AddRange( query1 ); List.AddRange(IEnumerable) Method (System.Collections.Generic) | Microsoft Docs[^]

How to write lambda linq query in C#?

11 Jan 2020 by Member 14169626

Table 1 COLUMN A COLUMN B COLUMN C 123 4 XXX 124 2 XYZ 125 4 LSK 142 4 TSY 156 2 ASA TABLE 2 COLUMNA COLUMNC COLUMNF COLUMNZ 123 XXX 0 QWRT 124 XYZ 0 ...

How to write lambda linq query in C#?

11 Jan 2020 by Maciej Los

This should've done the trick: var result = table2.Where(second=>second.columnf == 0 && table1.Any(first=>first.columnb == 4 && first.columna == second.columna)) .ToList();

How do I write a value that holds a string with lambda in C#?

8 Jan 2020 by Maciej Los

Seems you want to create a where statement dynamically. So, please read this: How to use expression trees to build dynamic queries (C#) | Microsoft Docs[^] Here[^], you you'll find quite simple example.

How do I write a value that holds a string with lambda in C#?

8 Jan 2020 by Member 14169626

Public void List() { string x=""; foreach( var item in t) { x= .... } } I want to write the string values in my hand in lambda. But when I write as where I get an error. What I have tried: var c=MyStudent.tblStudent.Select(x=>x.tblPerson).Distinct().ToList(); I want to where...

How do I write a value that holds a string with lambda in C#?

8 Jan 2020 by OriginalGriff

Where requires a condition, perhaps something like this: var c=MyStudent.tblStudent.Where(x => x.Contains("John")).Select(x=>x.tblPerson).Distinct().ToList();

I want to lambda expression intersect two query in C#?

2 Jan 2020 by Member 14169626

var q1= Mystudententities.Student.Select(x=>x.ID).ToList(); var q2= Mystudententities.Person.Select(x=>new { ID=x.ID, Name=x.Name }).ToList(); I want to find ids and names that are common to 2 query ids. How do I. Student ID 1 2 3 Person 1 Alex 2 John 4 Mary I...

entity-framework

I want to lambda expression intersect two query in C#?

2 Jan 2020 by Maciej Los

Take a look here: How To Use Join Operations With Database Using LINQ[^]

entity-framework

How to lambda expression two table select in C#?

29 Dec 2019 by Member 14169626

TABLE A: ColumnA , ColumnB , ColumnC , ColumnD TABLE B: ColumnA , ColumnB , ColumnC , ColumnD how do I select two query on the same columns and find partners with intersect? I want to table a => select a,b,c column where d=1 I want to table b => select a,b,c I...

entity-framework

How to lambda expression two table select in C#?

29 Dec 2019 by Aj@yGohil

Try this for select from table var selectedTableAList= (Your DB Context).tableA.Where(x => x.ColumnD == 1).Select(x => new { x.ColumnA, x.ColumnB, x.ColumnC })

entity-framework

How to lambda expression two table select in C#?

17 Dec 2019 by AFell2

Conjecturaly speaking, you will want to make your selections first and then intersect them. So, in SQL, you would do it this way: SELECT A.ColumnA, A.ColumnB, A.ColumnC, A.ColumnD FROM tableA AS A INNER JOIN tableB AS B ON A.ColumnA = B.ColumnA AND A.ColumnB = B.ColumnB ...

entity-framework

How to lambda expression two table select in C#?

17 Dec 2019 by Richard Deeming

The Where condition can only use properties from the projection it operates on. Move the Where before the Select (and fix the other syntax errors) and it will work. var tableA = MyStudentEntities.Where(x => x.ColumnD == 1).Select(x => new { x.ColumnA, x.ColumnB, x.ColumnC });

entity-framework

Mvc select second table data using linq

28 Nov 2019 by AleLo2014

hallo, I am new in mvc and linq. I've 2 table in relation many to many: 1)employe 2)device Selecting an employe I'd like to see his devices: -Marco -Franco Selecting Marco should appear the devices associated to him. In sql I'd like this: select Devices.nome from Devices where Devices.id...

Mvc select second table data using linq

28 Nov 2019 by AleLo2014

Phil found the solution (thank you so mutch!!!): ListDevice = db.Devices.Where(u => u.ImpiegatiDevices.Any(m => m.impiegatiID == id)).ToList();

Mvc select second table data using linq

28 Nov 2019 by phil.o

I'm quite confused since, for a many to many relationship, you need a third table. -- SQL pseudocode TABLE Employee ( EmployeeId int PRIMARY KEY IDENTITY, EmployeeName nvarchar ) TABLE Device ( DevideId int PRIMARY KEY IDENTITY, DeviceName nvarchar ) TABLE EmployeeDevice ( ...

An exception of type 'System.ArgumentException' occurred in EntityFramework.dll but was not handled in user code

16 Oct 2019 by Member 14624871

An exception of type 'System.ArgumentException' occurred in System.Web.Optimization.dll but was not handled in user code

entity-framework

An exception of type 'System.ArgumentException' occurred in EntityFramework.dll but was not handled in user code

16 Oct 2019 by Jahan Alem

I've faced a problem that is:An exception of type 'System.ArgumentException' occurred in EntityFramework.dll but was not handled in user codeAdditional information: The Include path expression must refer to a navigation property defined on the type. Use dotted paths for reference...

entity-framework

How to use lambda expression in C#?

7 Oct 2019 by Member 14169626

I want to sql query convert to lambda expression.How to use lambda expression this query. Class table: Id,Name,Surname School table: Id,Name,SchoolInformation Class Table: 1 Alex John 1 Alex Michael 1 Alex Martin 2 Mary Kelvin School Table: 1 Alex 2 Mary 3 Justin What I have...

How to use lambda expression in C#?

7 Oct 2019 by Maciej Los

Sorry, your question is unclear and/or your database is wrongly designed, because schoold.id and class.id can NOT be equal! A database model should looks like: 1 School => ∞ YearBooks 1 YearBook => ∞ Classes 1 Class => ∞ Students So, you need at least 4 objects (tables): 1. Yearbooks table - ...

How to use lambda expression in C#?

5 Oct 2019 by Rajat-Indiandotnet

I hope the following way helps you. List _lstStudent = new List(); List _lstSchool = new List(); _lstSchool.Add(new School() { Id = 1, Name = "MVM" }); _lstSchool.Add(new School() { Id = 2, Name = "DPS" }); ...

How to where condition in lambda expression in C#?

3 Sep 2019 by Member 14169626

Student table ID 1 2 3 4 ı want to select student where ıd=3. How to where condition lambda expression in c#? What I have tried: Select(t=>Student).where(x=>x.ID==3)

How to where condition in lambda expression in C#?

3 Sep 2019 by OriginalGriff

Try: var selected = studentsCollection.Where(s => s.ID == 3); or Student justTheOne = studentsCollection.Where(s => s.ID == 3).FirstOrDefault();

How do I select data from a table with lambda?

30 Aug 2019 by Member 14169626

I want to use entity lambda query and insert table.But I dont choose same area.How to select and where condition this area. SCHOOL TABLE SCHOOL ID // CLASS ID // CLASS NAME 1 1A 1 1 1B 1 1 1C 1 1 1D ...

How do I select data from a table with lambda?

29 Aug 2019 by Gerry Schmitz

.Where(s=>s.CLASSID). This where goes nowhere. And not much else.

How to select entity lambda query WPF in C#?

20 Aug 2019 by StudentSC

I want to select table one column. What I have tried: I error is: return entities.SchoolTable.Select(x=>x.Schoolname); //schoolname string to bool error. And I dont take schoolname this lambda expression.

How to select entity lambda query WPF in C#?

12 Aug 2019 by Maciej Los

If you want to get single name of school, this statement is incorrect: entities.SchoolTable.Select(x=>x.SchoolName); To be able to get single value, use this: entities.SchoolTable .Where(x=>x.SchoolName=="some school name") .Select(x=>x.SchoolName) .SingleOrDefault();

How do I have optional XML elements using LINQ lamda syntax?

12 Jul 2019 by Patrick Skelton

This is a follow-on to another question I asked here: https://www.codeproject.com/Answers/5162098/How-do-I-convert-this-LINQ-query-to-function-synta#answer1 I am generating the XML I require using the following code: bool includeDetails = true; XElement breakdown = new XElement ( "Breakdown",...

How do I have optional XML elements using LINQ lamda syntax?

12 Jul 2019 by Richard Deeming

As discussed in the comments, the code you've shown is correct, and the bug has now disappeared. Demo: Optional Xml | C# Online Compiler | .NET Fiddle[^]

How do I perform a query with a list in C#

7 May 2019 by BillWoodruff

To me this kind of code ... that will obviously not compile ... indicates you have not really studied the basics of using the powerful tools that Linq provides. Don't worry, though: everyone I know has gone through a learning curve to get somewhat fluent in using Linq :) Well, okay, imho,...

entity-framework

How do I perform a query with a list in C#

7 May 2019 by Member 14087498

Hi, I just was wondering if I can perform a Query just like that: What I have tried: List = _context.StudentClass .Where(sc => sc.ClassId == 1) .ToList(); List studentIdList = new List(); foreach (var student in...

entity-framework

How do I perform a query with a list in C#

6 May 2019 by Maciej Los

This piece of code is not clear to me: List studentIdList = new List(); foreach (var student in studentClassList ) { studentIdList = _context.Student.Where(st => st.Id == student.StudentId).ToList(); } If you would like to get list of students in a specific class, you should do...

entity-framework

How do I perform a query with a list in C#

6 May 2019 by Christian Graus

Just to add, you need to include the Linq namespace for that stuff to start working, otherwise you'll have a List class but not those operators List studentIdList = new List(); Also, this makes no sense. Set it to null if you need to set it inside a scope. Your code sets it over...

entity-framework

How do I perform a query with a list in C#

6 May 2019 by OriginalGriff

Well, you could ... if you got the names right, C# is case sensitive ... but it wouldn't do much that was useful. The assignment inside the loop means that the eventual result will be the final result only, because it "throws away" all previous results each time round the loop. You might want...

entity-framework

How to use operators(if else) in lambda expression

4 Mar 2019 by #realJSOP

I would do it this way: CurrentFinancialMovementData movementData = null; { CurrentFinancialMovementData movement1 = keys.OrderByDescending(s => s.LatestReserveDate) .ThenByDescending(x => x.ReserveDaySequence) ...

How to use operators(if else) in lambda expression

1 Mar 2019 by Member 9956700

CurrentFinancialMovementData movementData = keys.OrderByDescending(s => s.LatestReserveDate ?? s.LatestRecoveryReserveDate).ThenByDescending(x => x.ReserveDaySequence).First(); CurrentFinancialMovementData movementDataReserve = keys.Where(s => s.AmountType ==...

How to search in datatable by datetime

15 Dec 2018 by Member 14089908

Hello Everyone, I have a DataTable that contains three columns ID, Shift Start and Shift End ID | Shift Start | Shift End 1 | 4/12/2018 7:00:00 AM | 4/12/2018 11:00:00 PM Now the problem is i want to select all the records within this date and time. I tried the following code but not...

How to search in datatable by datetime

15 Dec 2018 by Patrice T

Quote: the problem is i want to select all the records within this date and time. I tried the following code but not working. You want to know which people were working at a given datetime (dt). It mean people with [Shift Start] before dt and [Shift End] after dt. the problem is than you did...

How to search in datatable by datetime

15 Dec 2018 by pkfox

Nothing to do with your question but never have spaces in column or table names - same goes for file and folder names - just sayin :-)

How to search in datatable by datetime

14 Dec 2018 by kiran0624

string str=4/12/2018 11:00:00 if your searching in sql table select * from table where endshit='4/12/2018 11:00:00';

How to search in datatable by datetime

14 Dec 2018 by RickZeeland

Here is my complete example, tested in VS2017 with .NET 4.5.1: using System; using System.Collections.Generic; using System.Data; using System.Diagnostics; using System.Linq; using System.Windows.Forms; namespace TestForm1 { /// /// Codeproject DataTable /// ...

How to search in datatable by datetime

14 Dec 2018 by RickZeeland

You can use LINQ like this: IEnumerable selectedRows = dt1.AsEnumerable() .Where(row => (row.Field("Shift Start") ("Shift End"))); foreach (DataRow row in selectedRows) { ...

C# - LEFT OUTER JOIN using lambda expression throws “object reference not set to an instance of an object”

20 Oct 2018 by OriginalGriff

This is one of the most common problems we get asked, and it's also the one we are least equipped to answer, but you are most equipped to answer yourself. Let me just explain what the error means: You have tried to use a variable, property, or a method return value but it contains null - which...

C# - LEFT OUTER JOIN using lambda expression throws “object reference not set to an instance of an object”

20 Oct 2018 by Member 13974276

I have two tables as shown below Table 1 - LR ID___________Name 1 A 2 B 3 C Table 2 - Mapper ID___________LRID 1 1 2 1 3 2 The Mapper table refers LR table. I am trying to get the data from LR table wherever the IDs...

Using lambda expression unable to do join, group by and where condition at a time in entity framework core

11 Jul 2018 by sri4dotnet

Hi, I am trying to do join, group by and where condition using lambda expression in entity frame core but unable to return the query as IQuerayable. Below is the code - _entities.Company.Join(_entities.Employee, com => com.Company_id, ...

entity-framework

Using lambda expression unable to do join, group by and where condition at a time in entity framework core

11 Jul 2018 by F-ES Sitecore

If you want it IQueryable then don't do the "ToListAsync" at the end.

entity-framework

Lambda query help with grouping and ordering.

18 May 2018 by #realJSOP

The structure of your objects (Car and CarOwner) prevents you from getting what you want (without additional coding). First, you shouldn't try to do everything in one line of code. IT's not that it's not possible, it's that it's bad practice because it is HIGHLY unmaintainable. Add this class:...

Lambda query help with grouping and ordering.

16 May 2018 by Clifford Nelson

var results = owners.Where(b => b.Cars != null) .GroupBy(o => o.Gender, o => o.Cars, (key, g) => new Result { Gender = key, Name = g.SelectMany(cars => cars) .Select(car => car.Name).Distinct().OrderBy(k => k).ToList() }); I forgot the...

Lambda query help with grouping and ordering.

16 May 2018 by sam_roy

public class Car { [JsonProperty("name")] public string Name{get;set;} [JsonProperty("type")] public string Type{get;set;} } public class CarOwner { [JsonProperty("name")] public string Name{get;set;} [JsonProperty("gender")]...

functionExtensions Techniques 1: Throwable Functional Interfaces

8 May 2018 by JIANGWilliam

This is the first of three episodes to introduce considerations and techniques used for the throwable functional interfaces defined in my open-sourced library functionExtensions.

Why does this lambda doesn't work with the delegate?

23 Mar 2018 by OriginalGriff

Quote: EDIT: Oooooh. It's the signature... Sorry for the stupid question........ It is indeed! For the benefit of others with a similar problem, the sh2 declaration requires a parameter: ReturnAStringHandler sh = ReturnAString; ReturnAStringHandler sh2 = (x) => sh(x); ...

Why does this lambda doesn't work with the delegate?

23 Mar 2018 by The_Unknown_Member

What's the problem with the following code? class Program { public delegate string ReturnAStringHandler(string s); static void Main(string[] args) { ReturnAStringHandler sh = ReturnAString; ReturnAStringHandler sh2 = () => sh("Hello"); ...

Optimising multiple streams and mappings into a single loop.

21 Mar 2018 by Member 13740593

I am trying to find the best way to optimise the converters below to follow the flow I call 'convertAndGroupForUpdate' first which triggers the conversions and relevant mappings. Any help to optimise this code would be massively appreciated. public List...

How to create class with multiple functions in aws lambda function

19 Feb 2018 by Richard MacCutchan

python aws lambda - Google Search[^]

select a single value from a list through lambda expression

14 Jan 2018 by maheshbisht

I have a list of class public class PrintUTAccural { public string PropertyName { get; set; } public string VendorName { get; set; } public string VendorNumber { get; set; } public string InvoiceNumber { get; set; } public...

Implement NOT in clause in LINQ

10 Jan 2018 by Member 11596389

Hi want to return a list of areas which dont appear in the current list of data; I have two list of data, once which contains a list of areas; A second one which contains the data i want to query the data list and return only where area does not exist in the list What I have tried: This...

Implement NOT in clause in LINQ

10 Jan 2018 by KHEMRAJ_UDR

try this may be help you.. c# - compare two list and return not matching items using linq - Stack Overflow[^]

Implement NOT in clause in LINQ

9 Jan 2018 by Maciej Los

Dependig on situation you may use: Except(TSource)[^] or Intersect(TSource) Method [^] or Any(TSource) Method[^]

Implement NOT in clause in LINQ

9 Jan 2018 by Dotnet_Dotnet

Sir the Demo code given bellow .For the match element Contains but for negative ! operator is used var exceptionList = new List { "exception1", "exception2" }; var query = myEntities.MyEntity .Select(e => e.Name) .Where(e =>...

Pass a system.io.stream by reference to a expression.parameter

2 Dec 2017 by Duncan Edwards Jones

I have a piece of code that is supposed to use Linq Expressions to put together a "compiled at run time" lambda function to persist events to a stream. (This is to allow the function to be swapped out by injection if you want to use a different serialisation technology) The code is:- Public...

Expression-Trees