DBNull.Value problem - C# Discussion Boards

Re: Differance Between Protected and protected internal

25-Jun-07 0:00

Rahul.RK wrote:
I want to know what is difference between protected and protected internal.

According to the documentation[^] the answer is:

protected = Access is limited to the containing class or types derived from the containing class
protected internal = Access is limited to the current assembly or types derived from the containing class

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Rahul.RK25-Jun-07 0:05

Rahul.RK

25-Jun-07 0:05

hello Thanks for reply...

i got the concept according to definition.

But as internal gives access to all the assembly then

what is use of protected?

Thats my question..

Rahul Kulkarni

Re: Differance Between Protected and protected internal

Colin Angus Mackay25-Jun-07 0:09

Re: Differance Between Protected and protected internal

25-Jun-07 0:09

Rahul.RK wrote:
But as internal gives access to all the assembly then what is use of protected?

So you can derive a class from it from outside the assembly.

Rahul.RK25-Jun-07 0:18

Rahul.RK

25-Jun-07 0:18

Thanks alot....

Will you please give me any helpfull site of book name

which will give me idea of all this basic fundamentals of C#.Net

Rahul Kulkarni

Re: Differance Between Protected and protected internal

Colin Angus Mackay25-Jun-07 0:23

Re: Differance Between Protected and protected internal

25-Jun-07 0:23

There are lots of beginner books. It really depends on your style of learning. Go to the book store and browse through a few books. Pick the one that appeals to you most.

Rahul.RK25-Jun-07 0:25

Rahul.RK

25-Jun-07 0:25

Thanks for help.

Rahul Kulkarni

DBNull.Value problem

t4ure4n24-Jun-07 23:46

24-Jun-07 23:46

Hello i am facing a slight problem with Store a record in the database.

I have a column of Type Decimal (It can have null values in the DB).
i take the input in a textbox and saves it to the database.

dataRow["SPEED"] = (this.tbSpeed.Text == "" ? DBNull.Value.ToString() : this.tbSpeed.Text);

If I leave it blank it gives me following error

An unhandled exception of type 'System.ArgumentException' occurred in System.Data.dll

Additional information: Input string was not in a correct format.Couldn't store <> in SPEED Column. Expected type is Decimal

What could be the solution to this problem

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Colin Angus Mackay24-Jun-07 23:55

24-Jun-07 23:55

t4urean wrote:
DBNull.Value.ToString()

Why are you suppling a ToString() on DBNull.Value? Don't do that just pass DBNull.Value

t4ure4n24-Jun-07 23:57

24-Jun-07 23:57

If I don't use DbNull.value.tostring() then i get the following error

Type of conditional expression cannot be determined because there is no implicit conversion between 'System.DBNull' and 'string'

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Colin Angus Mackay25-Jun-07 0:03

25-Jun-07 0:03

I suspect that is because of the trinary operator that you are using. These are generally considered to be bad practice.

Try this:

if (this.tbSpeed.Text == "")
     dataRow["SPEED"] = DBNull.Value;
else
     dataRow["SPEED"]  = this.tbSpeed.Text;

Colin Angus Mackay25-Jun-07 0:04

25-Jun-07 0:04

And I'd guess that that the contents of the text box will need to be converted to a decimal also.

martin_hughes25-Jun-07 1:07

martin_hughes

25-Jun-07 1:07

Try this:

dataRow["Speed"] = this.tbSpeed.Text ?? (object) DBNull.Value;

blackjack215025-Jun-07 0:20

blackjack2150

25-Jun-07 0:20

IF you would use a simple "IF", it would be very simple.

t4ure4n25-Jun-07 0:25

25-Jun-07 0:25

I have used this even then i am getting the same error

if (this.tbSpeed.Text == "")
dataRow["SPEED"] = DBNull.Value;//"NULL";
else
dataRow["SPEED"] = this.tbSpeed.Text;

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blackjack215025-Jun-07 0:51

blackjack2150

25-Jun-07 0:51

Your manner of storing values in the database seems pretty unusual. I would create a command with an "INSERT" statement as the command text and call it's ExecuteNonQuery() method. For the decimal column I would use an SQL Parameter of decimal type to avoid format errors.

t4ure4n25-Jun-07 0:56

dividing a windows forms in two

25-Jun-07 0:56

I have found the solution... Just applied the validation when creating the query string and it works fine to specify NUll for an empty string.

I am doing in the same way you are saying
but i have a seperate class that deals with it when provided with a data row.

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justintimberlake24-Jun-07 23:40

justintimberlake

24-Jun-07 23:40

how can i divide a windows forms in two half horizontally. The upper half contains one listview control and the lower half contains another list view control. and how can i manage the size when the form is expanded making sure that two list view doest overlap each other(i.e when form is expanded);

Colin Angus Mackay24-Jun-07 23:45

24-Jun-07 23:45

You can use a split container. It's in the toolbox. It creates two panels that you can put your controls into with a resizable divider. It ensures that the controls don't overlap. You can set it to be horizonal or vertical.

justintimberlake24-Jun-07 23:54

justintimberlake

24-Jun-07 23:54

is it availabe in dotnet 2003 or frame work 1.1

Colin Angus Mackay24-Jun-07 23:57

24-Jun-07 23:57

justintimberlake wrote:
is it availabe in dotnet 2003 or frame work 1.1

According to MSDN[^] the answer is no.

SQL Server Business Intelligence Development Studio?

mav.northwind25-Jun-07 19:02

mav.northwind

25-Jun-07 19:02

No, it isn't, but the Splitter control is.
You can simply add two Panels and a Splitter to your form to achieve a similar effect with .NET 1.1.

Regards,
mav

--
Black holes are the places where God divided by 0...

ASysSolvers24-Jun-07 23:30

ASysSolvers

24-Jun-07 23:30

Hi,
I installed the SQL Server 2005 with all components.
I need to do practice in that IDE As i study.but it not new->project template as i saw...it is same as visual studio 2005.

i neet BI IDE templates as its(default)
SQL Server Business Intelligence Development Studio.

Thanks in advance!

Re: SQL Server Business Intelligence Development Studio?

Colin Angus Mackay24-Jun-07 23:46