Re: Size of column name - C# Discussion Boards

Re: Size of column name

Thomas Weller21-Apr-09 23:36

Thomas Weller

21-Apr-09 23:36

myventsi wrote:
but it tells me

first of all: who/what is it (a component from your runtime environment or the database) ?

I guess it's the database? I can remember that MS SQL has a pretty narrow constraint on the length of identifiers, and I don't think that other DBMS are very different in this respect. If that's the case, you have no other choice than shortening the table name (you should do that anyway...).

Regards
Thomas

www.thomas-weller.de

Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning.
Programmer - an organism that turns coffee into software.

Re: Size of column name

Eddy Vluggen21-Apr-09 23:41

Eddy Vluggen

21-Apr-09 23:41

myventsi wrote:
CmdStr = "CREATE TABLE " + TableName + "([abcdefghi a abcdifg abc, abcef a abcdefg ab abcdefgh abc abcdefghij] TEXT";

myventsi wrote:
but it tells me that it' s too long.

What is too long? The table name or the column name? I don't think that it's the datatype that's causing trouble. Try this one for comparison;

CmdStr = "CREATE TABLE MyTableName ([MyColumName] TEXT";

I are troll Smile | :)

[Message Deleted]

hkjghkj121-Apr-09 23:50

hkjghkj1

21-Apr-09 23:50

[Message Deleted]

Re: Size of column name

Eddy Vluggen21-Apr-09 23:56

Eddy Vluggen

21-Apr-09 23:56

That means that this part:

[abcdefghi a abcdifg abc, abcef a abcdefg ab abcdefgh abc abcdefghij]

is too long in Access' opinion. She can be like that at times Frown | :(

I suggest you use a shorter, more descriptive column name. What things do you want to store in there?

I are troll Smile | :)

[Message Deleted]

hkjghkj122-Apr-09 0:02

hkjghkj1

22-Apr-09 0:02

[Message Deleted]

Re: Size of column name

Henry Minute22-Apr-09 0:11

Henry Minute

22-Apr-09 0:11

LONGTEXT means that the column can hold data up to 64000 characters in length. Not that its name can be up to 64000 characters.

Several people have already told you that the column name you are using is too long. Access has told you thet the column name you are using is too long.

Why don't you believe them?

For goodness sake use a shorter column name!!!

Henry Minute

Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”

[Message Deleted]

hkjghkj122-Apr-09 0:26

hkjghkj1

22-Apr-09 0:26

[Message Deleted]

Re: Size of column name

Skymir23-Apr-09 3:23

Skymir

23-Apr-09 3:23

You can have a shorter name, it just means re-arranging the data. Create another table to hold the names of the columns give each name a column number. Whenever you need data from one of the extra long column named columns, look up it's name/number and pull data from that column of the actual data table.

The true man wants two things: danger and play. For that reason he wants woman, as the most dangerous plaything.

My Ado.Net code is on a Public Holiday

Vimalsoft(Pty) Ltd21-Apr-09 23:20

Vimalsoft(Pty) Ltd

21-Apr-09 23:20

Good Afternoon All

As you know in South Africa today is a Election day, i think my ado.net code went to the Elections tooo

i have this code in my DAL

public DataSet Lis_Databases(String DB)
        {

            Strcon = GetConnectionString(DB);


            con = new SqlConnection(Strcon);

            cmdselect = new SqlCommand();

            cmdselect.CommandText = "[dbo].[sp_ListDatabasesOfType_Booking]";

            cmdselect.CommandType = CommandType.StoredProcedure;

            cmdselect.Connection = con;

            da = new SqlDataAdapter();

            da.SelectCommand = cmdselect;

            DataSet ds = new DataSet();

            try
            {
                con.Open();

                da.Fill(ds);
            }
            catch (SqlException)
            {
                throw;
            }
            finally
            {
                if (con != null)
                {
                    con.Close();
                }
            }

            return ds;

        }

and i call this code in my BLL like this

public DataSet Lis_Databases(String DB)
        {
            DAL.DAL obj = new DAL.DAL();

            DataSet ds = new DataSet();

            try
            {
                ds = obj.Lis_Databases(DB);
            }
            catch (SqlException)
            {   
                throw;
            }
            finally
            {

                obj = null;
            }
            return ds;
           
        }

And call use it like this in my PL(Presention Layer)

private void List_Databases_Grid()
    {
        
            BLL.BLL obj = new BLL.BLL();
        
            DataSet ds = new DataSet();

        try
        {

            ds = obj.Lis_Databases(Convert.ToString(Session["ActiveDatabase"]));

            if (ds.Tables[0].Rows.Count > 0)
            {
                GridView_Database_list.DataSource = ds;

                GridView_Database_list.DataBind();
            }
            else
            {
                lblMessage.Text = "No Booking Database Avaiable,Create one";
                lblMessage.Visible = true;
                lblMessage.ForeColor = System.Drawing.Color.Red;
            }
        }
        catch (SqlException ex)
        {
            lblMessage.Visible = true;
            lblMessage.Text = "The List cannot be Binded, Please Contact ITS" + ex.Message;
            lblMessage.ForeColor = System.Drawing.Color.Red;
        }
        finally
        {
            obj = null;
        }

    }

when my code Comes to this line

if (ds.Tables[0].Rows.Count > 0)
           {

The evualuation, it passes and that mean records had been returned, now when it gets to this line

GridView_Database_list.DataSource = ds;

it says

Object reference not set to an instance of an object.

i have Initialized the Dataset everywhere as you can see above

what have i done wrong?

You can still Comment on my Error handling

Thank you

Vuyiswa Maseko

Vuyiswa Maseko,

Few companies that installed computers to reduce the employment of clerks have realized their expectations.... They now need more and more expensive clerks even though they call them "Developers" or "Programmers."

C#/VB.NET/ASP.NET/SQL7/2000/2005/2008
http://www.vuyiswamaseko.tiyaneProperties.co.za
vuyiswa@its.co.za
http://www.itsabacus.co.za/itsabacus/

Re: My Ado.Net code is on a Public Holiday

Mbah Dhaim21-Apr-09 23:31

Mbah Dhaim

21-Apr-09 23:31

Vuyiswa Maseko wrote:
if (ds.Tables[0].Rows.Count > 0){

change that code to

if (ds.Tables.Count > 0 && ds.Tables[0].Rows.Count > 0){

hope it helps

dhaim
ing ngarso sung tulodho, ing madyo mangun karso, tut wuri handayani. "Ki Hajar Dewantoro"
in the front line gave a lead, in the middle line build goodwill, in the behind give power support

Re: My Ado.Net code is on a Public Holiday

Vimalsoft(Pty) Ltd21-Apr-09 23:36

Vimalsoft(Pty) Ltd

21-Apr-09 23:36

Good Day Mbah Dhaim

I have added such a Code to Check if there any rows and your code will check if there any tables in the dataset. but my Problem is here

GridView_Database_list.DataSource = ds;

i get

Object reference not set to an instance of an object.

Error

Thank you

Re: My Ado.Net code is on a Public Holiday

Greg Chelstowski21-Apr-09 23:46

Greg Chelstowski

21-Apr-09 23:46

OK, which object is it failing on, the gridview or the dataset?
(I don't see how it could possibly fail on the dataset though).

Is the Gridview actually in your controls collection?
Do you add it dynamically (in which case, before you add it do you actually instantiate it properly?) or is it a control in your aspx page?
And if so, if you're using frames are you not trying to access a control that is in a different frame?
Or maybe the gridview is in a content holder of and you're trying to access it from a master page?

var question = (_2b || !(_2b));

Re: My Ado.Net code is on a Public Holiday

Vimalsoft(Pty) Ltd22-Apr-09 0:00

Vimalsoft(Pty) Ltd

22-Apr-09 0:00

Thank you Greg

The GridView was inside the UpdateProgress Control Roll eyes | :rolleyes:

My Mistake, Thank you.

Re: My Ado.Net code is on a Public Holiday

Eddy Vluggen21-Apr-09 23:48

Eddy Vluggen

21-Apr-09 23:48

According to your logic, ds can't be empty. I guess that you already added a watch to verify that. Let's break the statement that the compiler is complaining about into some smaller parts;

GridView_Database_list.DataSource = ds;

Could it be that "GridView_Database_list" is null? Assigning a null-value to a variable isn't likely to cause errors, but assigning a value to something that is null, probably will.

--edit--
Read Greg's post - he's right in noticing that there may be some action triggered from the Grid itself once there is an assignment to the DataSource property Smile | :)

I are troll Smile | :)

Re: My Ado.Net code is on a Public Holiday

Vimalsoft(Pty) Ltd21-Apr-09 23:58

Vimalsoft(Pty) Ltd

21-Apr-09 23:58

Thanks for your Reply

The Gridview is Clean , there is nothing Assign to it.

Re: My Ado.Net code is on a Public Holiday

Mbah Dhaim21-Apr-09 23:54

Mbah Dhaim

21-Apr-09 23:54

DataSet is referenced type, as you see in your BLL and PL in finally part you destroy your object (DAL and BLL) : finally {obj = null}, your dataset in PL will be lost reference too.
remove finally part of your code.

hope it helps

Re: My Ado.Net code is on a Public Holiday

Vimalsoft(Pty) Ltd22-Apr-09 0:02

Vimalsoft(Pty) Ltd

22-Apr-09 0:02

No No the Finally Part will only Destroy the object not the Dataset, the Dataset will be Teturned Correctly. Thank you for your help i have the problem

The GridView was inside the UpdateProgress Control Roll eyes | :rolleyes:

My Mistake, Thank you.

Re: My Ado.Net code is on a Public Holiday

Mbah Dhaim22-Apr-09 0:10

Mbah Dhaim

22-Apr-09 0:10

Vuyiswa Maseko wrote:
My Mistake, Thank you.

you're welcome

this day i learn that referenced type will not destroy although its parent destroyed.
thank you very much.

Re: My Ado.Net code is on a Public Holiday

Vimalsoft(Pty) Ltd22-Apr-09 0:13

Vimalsoft(Pty) Ltd

22-Apr-09 0:13

You are Welcome Smile | :)

How to add Ticks to an axis using nPlot and c#

Mostrich21-Apr-09 22:59

Mostrich

21-Apr-09 22:59

Hi everybody,
i already plotted the content of a database with nplot.
The database contains only a few discrete values.
Now i am trying to add these exact ticks to my y-axis to increase readability.

Does anyone know how to add eight nonlinear spaces values as ticks to an y-axis using nplot and c#?

Muchas gracias

Identify the message end

yesu prakash21-Apr-09 22:59

yesu prakash

21-Apr-09 22:59

Hi,
How can i identify the message end in a socket communucation
eg:
when a client send byte[] to another client, the message went part by part. In the client side how can i identify the message is end. If the message is recived fully then i need to do next function.

Thankyou
YPKI

Re: Identify the message end

Rob Philpott21-Apr-09 23:13

Rob Philpott

21-Apr-09 23:13

A lot like strings, either send the size of the message prior to the message so the receiver knows how much to read, or use some sort of delimter to mark the end of the message.

Regards,
Rob Philpott.

[Message Deleted]

girishsatya21-Apr-09 22:47

girishsatya

21-Apr-09 22:47

[Message Deleted]

Re: DLL creating

Rob Philpott21-Apr-09 22:49

Rob Philpott

21-Apr-09 22:49

Dude, I don't have a clue what you're on about.

Regards,
Rob Philpott.

Re: DLL creating

yesu prakash21-Apr-09 23:04

yesu prakash

21-Apr-09 23:04

open project a class library
in class library---

public classlibrary
{
public void getfromdll(string name)
{
//display name
}
}

build -- u can get the dll from bin folder

in your application reffer the dll.

create an object of classlibrary..
call
getfromdll("Hi");

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