Sql Query titbits

Generate Dates and hour between Date Range

 DECLARE 

  @start DateTime = getdate() -1, 

  @end   DateTime = getdate();

;

WITH Dates_CTE

     AS (SELECT @start AS Dates

         UNION ALL

         SELECT Dateadd(hh, 1, Dates)

         FROM   Dates_CTE

         WHERE  Dates < @end)

SELECT DAY(dates),DATEPART(hour,Dates)

FROM   Dates_CTE

OPTION (MAXRECURSION 0) 

Got better queries? .. Add in comment .. Thanks

ef core tips

 Debug code-first Entity Framework migration codes

 Place this piece of code right above the migration you want to debug:

  if (!System.Diagnostics.Debugger.IsAttached)
            System.Diagnostics.Debugger.Launch();

More details / Ref  : https://stackoverflow.com/a/52700520/193061

Powershell TitBits

Replace all file names in a folder

Get-ChildItem -Filter “*ModelMap*” -Recurse | Rename-Item -NewName {$_.name -replace ‘ModelMap’ ,’ModelMapping’ }

Java To C# mapping

   Java          C#

   Map      Dictionary
   Set      HashSet
   Pair      KeyValuePair 
   .map              .Select       
   .collect          .ToList()
   .stream           .AsEnumerable 
   LinkedHashSet     <Need custom impl >
   flatMap()         SelectMany
   format()      String.format()
   zip( .Zip(
   joining() String.Join(
   InstStream(1,100)  Enumerable.Range(1, 100)
   Function    Func 
   .apply(           .Invoke(
   .isEmpty()   .Any()
   .size()   .Count
   .filter(           .Where(
   BiFunction    Func
   

Addins for Software tools

SQL management addins



VS Code Addins

• Javascript/ Typescript  
• Prettier 
• using powershell
• https://4sysops.com/archives/make-visual-studio-code-look-and-behave-like-powershell-ise/ 
• d
• 
  
• 
  

RxJs Excellent posts

RxJs Excellent posts

RxJS Operators for Dummies: forkJoin, zip, combineLatest, withLatestFrom
https://scotch.io/tutorials/rxjs-operators-for-dummies-forkjoin-zip-combinelatest-withlatestfrom

using Linq methods with caution - E.g FirstorDefault()

Don't use FirstorDefault() unless you are sure its valid/ verified in the business scenario. else you are going to introduce bugs in the code.