Visual Basic

Re: How To Check if update statement is executed successfully (qry.ExecuteScalar)

19-Jan-06 19:43

Thnx guys for your reply. I will try out your solution. However, what I need to know is whether every execute statement is successfully completed. If not, then I need to maintain a log of the records (ID's, Price) which have not been executed successfully for the user to analyze. How can this be done.
Thnx again.

With Best Regards,

Mayur

-- modified at 1:43 Friday 20th January, 2006

Owner drawn19-Jan-06 20:21

Owner drawn

19-Jan-06 20:21

mayhem_rules wrote:
However, what I need to know is whether every execute statement is successfully completed.

That is what ExecuteNonQuery returns.

It returns the number of rows affected by the said query. So if it returns 0 it means no rows affected.

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Re: How To Check if update statement is executed successfully (qry.ExecuteScalar)

mayhem_rules19-Jan-06 20:25

Re: How To Check if update statement is executed successfully (qry.ExecuteScalar)

19-Jan-06 20:25

Thnx, I will try it out and let you know. Another query that I have is how do I maintain a log file to record all the transactions.

With Best Regards,

Mayur

Owner drawn19-Jan-06 20:29

Owner drawn

19-Jan-06 20:29

I suggest you write a custom class for that.

Now use that class to execute all sorts of query in your application.

You must have a function that acts as a common entry point for executing these queries.
Probably an enum will help you determining the type of query.

Now in this function you can make log entries for all kinds of queries since you are now sure that nothing in your application can interact with database without using this function. So it acts as a common entry point.

Jesus Loves Rose | [Rose]

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--Owner Drawn Rose | [Rose]

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--Never say quits
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Re: How To Check if update statement is executed successfully (qry.ExecuteScalar)

mayhem_rules19-Jan-06 20:45

Re: How To Check if update statement is executed successfully (qry.ExecuteScalar)

19-Jan-06 20:45

Thnx. But I am a real fresher in .NET. The instructions that you have provided have gone way above my head Confused | :confused:

. I wil be glad if you could explain it to me in some simpler terms.

With Best Regards,

Mayur

Dave Kreskowiak20-Jan-06 1:56

Re: How To Check if update statement is executed successfully (qry.ExecuteScalar)

20-Jan-06 1:56

This can be done is the database's SQL code. Table triggers are commonly used to log information such as this.

Though, this technique is not supported in Access! Real SQL databases only!

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Colin Angus Mackay19-Jan-06 22:39

Colin Angus Mackay

19-Jan-06 22:39

mayhem_rules wrote:
inssql = "Update PriceTable set Price = " & newprice & " where ID = '" & id1 & "' and Period = '" & Trim(period) & "'"

Please learn about SQL Injection Attacks and tips on how to prevent them[^] otherwise this code is going to get you 0wn3d!!!!111

ColinMackay.net
"Man who stand on hill with mouth open will wait long time for roast duck to drop in." -- Confucius
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Re: How To Check if update statement is executed successfully (qry.ExecuteScalar)

mayhem_rules19-Jan-06 23:27

Re: How To Check if update statement is executed successfully (qry.ExecuteScalar)

19-Jan-06 23:27

Sorry, did not get you. Neway, I m using MS Access. some usefull tips will be helpful.

With Best Regards,

Mayur

Colin Angus Mackay19-Jan-06 23:46

Colin Angus Mackay

19-Jan-06 23:46

mayhem_rules wrote:
Sorry, did not get you.

Your code is succeptable to a SQL Injection Attack. A mallicious attacker could gain control of your database through your web application if you don't defend it.

The article I linked to will explain what a SQL Injection Attack is and it will give some advice on how to defend yourself from it.

mayhem_rules wrote:
Neway, I m using MS Access

Dismissive attitudes like this cause security problems. Regardless of the database platform you are using you need to at least understand what security threats exist in order for you to put together even a basic plan of defence.

ColinMackay.net
"Man who stand on hill with mouth open will wait long time for roast duck to drop in." -- Confucius
"If a man empties his purse into his head, no man can take it away from him, for an investment in knowledge pays the best interest." -- Joseph E. O'Donnell

trap mouse into a window form

x86phre3x19-Jan-06 18:41

x86phre3x

19-Jan-06 18:41

Anyone here knows how to trap the mouse cursor in the main form of a vb .net application? so that the user won't be able to use windows until it is unlock. can somebody help me with this?

Re: trap mouse into a window form

Dave Kreskowiak20-Jan-06 1:51

Re: Entering Items in Combo

20-Jan-06 1:51

You can track the mouse position with the Form's MouseMove event. Then handle the Form's MouseLeave event, and reset the mouse to the last known position recorded by the code in MouseMove through the Form's Cursor property.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

-- modified at 7:51 Friday 20th January, 2006

Entering Items in Combo

Muhammad Javed Khan19-Jan-06 17:54

Muhammad Javed Khan

19-Jan-06 17:54

Hello All

I want to manually enter items in the combox as:

cbo.Items.Add("Supplier")<br />
cbo.Items.Add("Customer")

How i can add ValueMember Field data manually? As we have an option in VB6 as:

cbo.AddItem ("Supplier")<br />
cbo.ItemData(cbo.NewIndex) = 1 'How this can be done in VB.Net?<br />
<br />
cbo.AddItem ("Customer")<br />
cbo.ItemData(cbo.NewIndex) = 2 'How this can be done in VB.Net?

''''''''''' I have done this way is there any solution better than this? ''

<br />
            Dim lDT As New DataTable<br />
            Dim col As DataColumn<br />
            Dim row As DataRow<br />
<br />
            col = New DataColumn<br />
            col.ColumnName = "PartyClassType"<br />
            lDT.Columns.Add(col)<br />
<br />
            col = New DataColumn<br />
            col.ColumnName = "PartyClassTypeID"<br />
            lDT.Columns.Add(col)<br />
<br />
            row = lDT.NewRow<br />
            row(0) = "Supplier"<br />
            row(1) = "S"<br />
            lDT.Rows.Add(row)<br />
<br />
            row = lDT.NewRow<br />
            row(0) = "Customer"<br />
            row(1) = "C"<br />
            lDT.Rows.Add(row)<br />
            With cbo<br />
                .DisplayMember = "PartyClassType"<br />
                .ValueMember = "PartyClassTypeID"<br />
                .DataSource = lDT<br />
            End With<br />

Regards

Owner drawn19-Jan-06 18:28

Owner drawn

19-Jan-06 18:28

Try maintaining a parallel collection along with the items in the ComboBox

Jesus Loves Rose | [Rose]

<marquee direction="up" height="40" scrolldelay="1" step="1" scrollamount="1" style="background:#aabbcc;border-bottom:thin solid 1px #6699cc">
--Owner Drawn Rose | [Rose]

--Nothing special
--Defeat is temporary but surrender is permanent
--Never say quits
--Jesus is Lord Rose | [Rose]

Question about .Net

shiroamachi19-Jan-06 17:21

shiroamachi

19-Jan-06 17:21

I was wondering, is there any differences between :

1.

<code>
Import System.Data.Oledb
Dim con as New OledbConnection()
</code>

and

<code>Dim con as new Oledb.OledbConnection() </code>

Dim myString as string = "bla bla bla"</code>

and 

<code>Dim myString as String
myString = "bla bla bla"

or it's simply personal preference?

WiL

Re: Question about .Net

Dave Kreskowiak19-Jan-06 17:43

about writing object/class to the HDD?

19-Jan-06 17:43

1. No. They're exactly the same. In the second Dim statement, you just needlessly typed the extra namespace specifier (OleDb.) You don't have to because the namespace is specifically imported in the first line of code.

2. No. It's just a matter of preference. They're functionaly the same.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

flashmemory19-Jan-06 10:28

flashmemory

19-Jan-06 10:28

when i define a new class/module so it is a new datatype..
i can define an object from it,, how i can save the object to a file on the hard disk and to retrieve it(load from file)???

Re: about writing object/class to the HDD?

Christian Graus19-Jan-06 11:20

Christian Graus

19-Jan-06 11:20

I'm not sure what default serialisation code exists, but you probably need to write code to save the data in your class, and to reload it.

Christian Graus - Microsoft MVP - C++

about using barcode in vb.net??

flashmemory19-Jan-06 10:19

flashmemory

19-Jan-06 10:19

i need a sample code in vb.net to write/read a barcode?

Re: about using barcode in vb.net??

Dave Kreskowiak19-Jan-06 10:38

19-Jan-06 10:38

Google is your friend and the code you write will depend HEAVILY on the barcode scanner your using. There is no "generic" code that works with every barcode scanner out there.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

number of affected rows

ecentinela19-Jan-06 7:35

ecentinela

19-Jan-06 7:35

When I make a query in sql server 2005 like "SELECT something FROM somewhere", there is a way to know the number of selected rows without the need of other query "SELECT COUNT(*) FROM somewhere" ?

Thanks

Dave Kreskowiak19-Jan-06 7:41

19-Jan-06 7:41

This is returned automatically unless the SELECT statement is preceded by a SELECT NOCOUNT ON statement. This is not applicable to Access databases though. Jet doesn't support returning the "number of rows affected".

What is it your're trying to do. So far, this question has nothing to do with VB.NET...

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

ecentinela19-Jan-06 7:46

ecentinela

19-Jan-06 7:46

I want to redim an array to the number of rows selected, and fill this array from one of the columns of the query.

Dave Kreskowiak19-Jan-06 8:29

19-Jan-06 8:29

Then you're looking in the wrong place. Fill your DataSet, DataTable, or whatver your using to store the results of the query. Then use the count of the number of Rows in the collection to set your array dimensions.

Dim ds As DataSet
' code to fill DataSet with a couple of tables...
Dim arraySize As Integer
arraySize = ds.Tables("whatever").Rows.Count
Dim myArray(arraySize) As String
.
.
.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome