Tag Archives: join

LINQ Join with Multiple From Clauses

Questions: When writing LINQ queries in C#, I know I can perform a join using the join keyword. But what does the following do? from c in Companies from e in c.Employees select e; A LINQ book I have say it’s a type of join, but not a proper join (which uses the join keyword).… Read More »

Regular Expression in a join using Linq c#?

Questions: Is it possible to use a regular expressing in a join using linq. For example: A Student table contains a field called Subjects with a comma separated value such as “Maths,English,Science”. A Subject table contains a row for each subject having the subject in a Name field. I want to do an inner join… Read More »

LINQ Conditionally use different fields to join

Questions: I have this situation: Table A Field A Field B d 1 d 2 d 3 Table B Field A Field B d 1 d 2 d 3 d 4 I want the “4” in Table B to match to the “3” in Table A. Here’s my code currently: short maxFieldB = DatabaseContext.TableA .OrderByDescending(x… Read More »

C# Linq – handle outer join and cartesian product

Questions: Hi Stack Overflow community, I have a stored procedure (that I can’t modify, so can only deal with the returned data) that can return data like this: Group Code Value =========================== GroupA 13 123 GroupA 17 456 GroupB 17 789 However, I need to manipulate this result data to look like this: Group Code… Read More »

MultiUserChatException$NotAMucServiceException: Can not join … , because 'localhost' does not provide a MUC (XEP-45) service

Questions: Component using: ejabberd- 18.06 and SMACK-4.2.4 I have installed Spark ejabberd client in my PC and there I can create chat room. But When I rum the below code it get the below exception. I tried on Android emulator and phone also, connected on same local network. SMACK ERROR: W/System.err: org.jivesoftware.smackx.muc.MultiUserChatException$NotAMucServiceException: Can not join… Read More »

String.Join overload not recognized

Questions: I have code equivalent to String.Join(‘,’, new List<ulong>()) in a .NET Standard 2.0 project. I get two error from this line: Argument 1: cannot convert from ‘char’ to ‘string’ Argument 2: cannot convert from ‘System.Collections.Generic.List<ulong>’ to ‘System.Collections.Generic.IEnumerable<string>’ These are the overloads of String.Join ReSharper shows on navigating to symbol: I would assume that the… Read More »

database INNER JOIN

Questions: These are the two set up tables LOGIN TABLE USER’S NAME I want to create something like the User will key in their USER_ID and USER_PWD in a textbox. IF the user successfully login, it will say ” HI + PATNAME “. I have created this code so far but it isnt working. string… Read More »