Expression Lambda to order fields with null value

Expression Lambda to order fields with null value

Content Index :

Expression Lambda to order fields with null value
Tag : vb.net , By : user171752
Date : November 23 2020, 01:01 AM

Hope that helps You can change your toStr expression to include a Coalesce operation where the right expression is a constant. Note that the left expression needs to be reference type (or a nullable value type) so you also need to ensure that the property type is not a value type.
Here's an example that should work:
Dim toStr As Expression = Expression.Call(
    If(pinfo.PropertyType.IsValueType, expr, Expression.Coalesce(expr, Expression.Constant(String.Empty))),

No Comments Right Now !

Boards Message :
You Must Login Or Sign Up to Add Your Comments .

Share : facebook icon twitter icon

Lambda Expression to Group by 3 different Fields only when not null and count()

Tag : development , By : jsmb
Date : March 29 2020, 07:55 AM
wish help you to fix your issue Here's the model I have. , The following will work.
 var notificationCount = db.Notifications
      .GroupBy(x => new { x.CommentID, x.ProjectID, x.BookID, x.NotificationTypeID })

Lambda Expression : How to Concat 2 Fields?

Tag : asp.net-mvc , By : Ben Brown
Date : March 29 2020, 07:55 AM
wish helps you You rock! Thank you very much for your great help. Actually I have encountered "LINQ to Entities does not recognize the method 'System.String Format(System.String, System.Object, System.Object)' method, and this method cannot be translated into a store expression." error message after first applying your method, but by adding ".ToList()" to the third line I have succeeded. So, for informing those who might need this great functionality here is the last state of the method in my Controller:
private void PopulateMeetingsDropDownList(object selectedMeetings = null)
    var meetingsQuery = repository.Meetings.ToList()
        .Join(repository.Cities, m => m.MeetingCityId, c => c.CityID,
                (m, c) => new
                    CityID = c.CityID,
                    DisplayValue = string.Format("{0} ({1:dd MMMM yyyy})", c.CityName, m.MeetingStartDate) 
       .OrderBy(x => x.CityID).ToList();
    ViewData["MeetingId"] = new SelectList(meetingsQuery, "CityID", "DisplayValue", selectedMeetings); 

Order By in List<T> with Lambda Expression when foreign key is null

Tag : chash , By : itsmegb
Date : March 29 2020, 07:55 AM
I hope this helps . You can extend your lambda expression or using c# 6 features:
// use c# 6.0 ?. operator
listData = db.db_table
             .OrderBy(x => x.db_table1?.column_name)

// check value manually
listData = db.db_table
             .OrderBy(x => x.db_table1 != null ? x.db_table1.column_name : string.Empty)

// filter null values before sorting
listData = db.db_table
             .Where(x => x.db_table1 != null)
             .OrderBy(x => x.db_table1.column_name)

python lambda expression with dynamic fields

Tag : python , By : snapshooter
Date : March 29 2020, 07:55 AM
hope this fix your issue You need an all function which is only true if every element of an iterable is True. Otherwise every input to your filter was returning True.
list(filter(lambda d: all(d[field] == reference_row[field] for field in compare_fields), my_list))
[d for d in my_list if 
 all(d[field] == reference_row[field] for field in compare_fields)]

Is there a C# syntax for a 'null' lambda expression? eg, calling OrderBy(x => x) without the lambda expression?

Tag : chash , By : Ed.
Date : March 29 2020, 07:55 AM
Related Posts Related QUESTIONS :
  • null exception on a for each control var
  • How to use a string variable in a directory path
  • How can 2 Character instead of 1 in My Textbox?
  • How to get the os name of selected computer in vb.net?
  • How to test to see if a computer has Excel installed (any version)?
  • Determine location to install software with ClickOnce deployment
  • How to read excel file in vb.net 2003
  • Object Naming without Hungarian?
  • How to use ToolStripMenuItems without mouse events ( click or double Click event )?
  • Call a DOS command and redirect the output to a file
  • Unknown Publisher when I install application I wrote?
  • Tips for transitioning from Visual Basic to Xcode
  • Tools to convert option strict off code into option strict on?
  • DATE concept in VB.NET
  • Convert From Custom List to List of String
  • How to make all possible sum combinations from array elements in VB
  • How to draw XNA window inside a panel?
  • change the master page body color from different pages when they load in vb.net
  • Cannot iterate of a collection of Anonymous Types created from a LINQ Query in VB.NET
  • " addressof " VB6 to VB.NET
  • How can I accelerate the generation of the an MD5 Checksum within vb.net?
  • replace " in vb.net
  • Understanding RTF and edit it with vb.net
  • Screen Scraping - still not working
  • Obtaining reference to Class instance by string name - VB.NET
  • Get all folder / directories list in VB.net
  • How do I send keystrokes to a serial port in vb.net?
  • vb.net vs. framework
  • How do you determine if there is an error when using the VB.Net Shell Command?
  • Operand type clash: nvarchar is incompatible with image
  • Replace line feed (LF) characters in a String using VB.NET
  • How to make ComboBox boarder to be Fixed 3D
  • Warning BC42025 when trying to applying VisualStyler.ApplyExcludeTag() method to Tab Control
  • deserialization of nested JSON from Cratejoy
  • Need to close program to see datagrid changes after making a search query and update the results
  • How to stop flickering when redrawing ellipses in windows forms
  • DataTable is empty in release mode, but not in debug mode although I initialized it
  • How to use SQL IN statement with list of Items selected from treeviewlist?
  • Why is my loop through a form control array stopping one short?
  • How to Pass Different EventArgs to another sub
  • Is there any way to switch off Auto Register Feature so that it ignores any dll files in the same folder?
  • Errors from different form goes to catch on other form
  • How to compare only month and year? [VB]
  • Do something in the Background without freezing the Program
  • how can i create dynamically flowlayoutpanels and tabpages in my form
  • capture image from webcam video (aforge)
  • This code is used to sort items in a list view by column, but how does it work?
  • how to fix the encryption not giving the correct message for words
  • Can I create a schedule to run a function within my web app on Azure, and if possible passit parameters?
  • How to save data into database from dynamically created text boxes
  • Importing a one line CSV in to a multi row datagridview
  • Legacy VSTO add in deactivated in Outlook 2016
  • How do I get only one result for each app instead of double?
  • How to check if listbox2 contains some listbox1 items - VB.net
  • How to disable SortMode in dynamically load table?
  • Compiler error when calling async Sub with TaskFactory
  • Load data in a chart. Problem, loading the same value from the table to the chart
  • Windows application wont read all data from serial port
  • I have a problem with not readable response string from a web request in vb.net
  • Deep copy a CUSTOM treenode
  • shadow
    Privacy Policy - Terms - Contact Us © scrbit.com