nullvalue

Setting DataGridView.DefaultCellStyle.NullValue to null at designtime raises error at adding rows runtime.

In Visual Studio 2008 add a new DataGridView to a form Edit Columns Add a a new DataGridViewImageColumn Open the CellStyle Builder of this column (DefaultCellStyle property) Change the NullValue from System.Drawing.Bitmap to null Try to add a new Row to the DataGridView at runtime (dataGridView1.Rows.Add();) You get this error: System....

.NET DBNull vs Nothing across all variable types?

I am a little confused about null values and variables in .NET. (VB preferred) Is there any way to check the "nullness" of ANY given variable regardless of whether it was an object or a value type? Or does my null check have to always anticipate whether it's checking a value type (e.g. System.Integer) or an object? I guess what I'm lo...

Passing null arguments to C# methods

Hi, Is there a way to pass null arguments to C# methods (something like null arguments in c++)? For example: Is it possible to translate the following c++ function to C# method: private void Example(int* arg1, int* arg2) { if(arg1 == null) { //do something } if(arg2 == null) { //do something else ...

DateTimePicker Null Value (.NET)

What's the easiest/most robust way of altering the DateTimePicker control to allow the user to enter 'null' values? ...

Java method dispatch with null argument

Why does it (apparently) make a difference whether I pass null as an argument directly, or pass an Object that I assigned the value null? Object testVal = null; test.foo(testVal); // dispatched to foo(Object) // test.foo(null); // compilation problem -> "The method foo(String) is ambiguous" public void foo(String arg) { // More-...

SQL nvl equivalent - without if/case statements & isnull & coalesce

Are there any nvl() equivalent functions in SQL? Or something close enough to be used in the same way in certain scenarios? UPDATE: no if statementsno case statementsno isnullno coalesce select nvl (purge_date,"SODIUFOSDIUFSDOIFUDSF") from id_rec where id=36581; (expression) SODIUFOSDIUFSDOIFUDSF 1 row(s) retrieved. select isnul...

Stored Procedure parameter inserting wrong value

Good afternoon everyone, I am having an issue with a stored procedure inserting an incorrect value. Below is a summarization of my stored procedure ... set ANSI_NULLS ON set QUOTED_IDENTIFIER ON go CREATE PROCEDURE [dbo].[InsertDifferential] @differential int = null AS BEGIN TRY BEGIN TRANSACTION UPDATE Dif...

Validate if a column has a null value

Which SQL would be faster to validate if a particular column has a null value or not, why? 1) SELECT * FROM TABLE1 WHERE COL1 IS NULL Execute this query and then check if you are able to read any records. If yes there are null values. 2) SELECT COUNT(COL1) FROM TABLE1 WHERE COL1 IS NULL Read the count which is returned to determine i...

Django filter -- How do I go about filtering for emply or NULL names in a queryset

Hi, I have first_name, last_name & alias (optional) which I need to search for. So, I need a query to give me all the names that have an alias set. Only if I could do: Name.objects.filter(alias!="") So, what is the equivalent to the above? Thanks, VN44CA ...

SQL QUERY replace NULL value in a row with a value from the previous known value

I have 2 columns date number ---- ------ 1 3 2 NULL 3 5 4 NULL 5 NULL 6 2 ....... I need to replace the NULL values with new values takes on the value from the last known value in the previous date in the date column eg: date=2 number = 3,...

ASP.NET Drop Down List error with null values in SqlDataSource

Hi, I have a drop down list on a form view which are both bound to different data sources. When trying to run the program I am getting 'ddlFieldName' has a SelectedValue which is invalid because it does not exist in the list of items. Parameter name: value. I think it is because the field associated with the drop down list contains ...

Combobox with null value - SelectedItem binding

I would like to have a combobox with cities options to choose, one of the option is an empty option (no city). The itemsource is binded to the List of "City" objects. The List contains null value to represent an empty option. The SelectedItem is binded to a property of "City" type. Everything works except the situation when the empty opt...

executing null values records

i am trying to execute the records that have TotalTime null value from the table NewTimeAttendance...TotalTime datatype nchar(10) select * from newtimeattendance where TotalTime = 'NULL' ....nothing select * from newtimeattendance where TotalTime = 'null' ....nothing select * from newtimeattendance where TotalTime = 'Null' .....