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Im not sure I understand what you want. If you just want the last row then<br />
&nbsp;<br />
<br />

<pre><code class="code-1 nolinks" id="code-208309"><span>If Me.CaD_PRO_Plus_Datasat21.CAD.Rows.Count &gt; 0 Then</span>
<span>            Me.EventNumberHiddenTextBox.Text = (Me.CaD_PRO_Plus_Datasat21.CAD.Rows.Count -1).ToString();</span>
</code></pre>
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It sounds like your first record gets the number zero. Are you using the value in the text box when you add the record to the database, or is the number created some other way? Perhaps an identity/autonumber field?<br />
<br />
Is the table that you have sorted on the number? Otherwise you can't be sure that the highest number is last in the table.<br />
<br />
I don't see anything in your code that would increase the number that you get from the table. What's in the 28th column of the table, really?<br />
<br />
I hope that you are not fetching the contents of the entire table only to get the next number? That would be a real waste of resources, as you could easily make a query that would return only that information.
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@ororiole:<br />
<br />
That would just put the number of records minus one in the text box, not any data from the table.
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GreenGhost<br />
<br />
I have an autonumber field but ran into a problem. At some point (probably on a timer) I will clear the dataset and reload as to refresh the form. The data comes from an XML file and there could be multiple users so I need all screens to show the same data. The problem I ran into is when I reload the datatable for some crazy reason my autonumber fileds gets all screwed up. I might have 1,2 then 4 then 8. <br />
<br />
So to try and solve I wanted to make my own. The 27th column was added solely to be another autonumber field but created by me. So when the first record is added it would be number1. Then everytime you add a record it would check for the last number and add 1. This works except for the first two records are always number 1.
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I know what that does. But's not not clear what he wants. Thats why I asked him if he just wants the last row number. Then the next row would be plus 1. If he just wants the next number then it would be Count. But neither of us know whats going in column(27).
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ororiole<br />
<br />
row.count will not work because I can get duplicate numbers.
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ororiole<br />
<br />
Not sure what you mean by what I mean? :-)<br />
<br />
I made a datatable and based my form on the datatable. The datatable writes to an XML file were all the data is stored. So column 27's value is created by the user adding a new record. Just like an autonumber. <br />
<br />
So when they click new record I want to check column 27 and add 1 to the last records value.<br />
<br />
This was the original question<br />
<br />
<a href="https://www.experts-exchange.com/questions/23782779/Custom-autonumber-field.html" rel="ugc">https://www.experts-exchange.com/questions/23782779/Custom-autonumber-field.html</a>
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The underlying problem would probably try and figure out why my autonumber field gets wacky.
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As you are using an autonumber field and have multiple users, you can not get the number of the next record that the user creates. It's simply not possible.<br />
<br />
Assuming that the numbers created really are consecutive, you can predict what number the next record will get, but you don't know which user will create the next record.<br />
<br />
As I said, I don't see anything in your code that would increase the number. You should get the same number over and over.
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When they create a new record the dataset would clear then load to give the latest data so not to get the same number twice. The problem is not that they are in order (I don't care about that) just that they don't get the same number twice. The original question was to create a custom autonumber field. Not sure why (more of an access guy myself) but it works. Just get the number 1 twice before it starts counting up by ones.
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If this is not correct please let me know. Any ideas of a better way or why my autonumber field is wacky?<br />
<br />
Here is the code behind the dataset<br />
<br />
Partial Class CAD_PRO_Plus_Datasat2<br />
&nbsp; &nbsp; <br />
&nbsp; &nbsp; Private mXmlFilePath2 As String = &quot;c:\CAD_PRO_Plus\CAD.xml&quot;<br />
<br />
&nbsp; &nbsp; Public Sub LoadCAD2()<br />
&nbsp; &nbsp; &nbsp; &nbsp; If My.Computer.FileSystem.Fil<wbr />eExists(mX<wbr />mlFilePath<wbr />2) = True Then<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Me.ReadXml(mXmlFilePath2)<br />
&nbsp; &nbsp; &nbsp; &nbsp; End If<br />
&nbsp; &nbsp; End Sub<br />
&nbsp; &nbsp; 'Save CAD Data<br />
&nbsp; &nbsp; Public Sub SaveCAD2()<br />
&nbsp; &nbsp; &nbsp; &nbsp; Me.WriteXml(mXmlFilePath2,<wbr /> XmlWriteMode.WriteSchema)<br />
&nbsp; &nbsp; End Sub<br />
&nbsp; &nbsp; Public Sub ClearCAD2()<br />
&nbsp; &nbsp; &nbsp; &nbsp; If My.Computer.FileSystem.Fil<wbr />eExists(mX<wbr />mlFilePath<wbr />2) = True Then<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Me.tableCAD.Dispose()<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Me.Clear()<br />
&nbsp; &nbsp; &nbsp; &nbsp; End If<br />
&nbsp; &nbsp; End Sub<br />
End Class<br />
<br />
In the form load I use:<br />
&nbsp;LoadCAD2()<br />
<br />
<br />
Then I have a refresh button that I use:<br />
<br />
CaD_PRO_Plus_Datasat21.Cle<wbr />arCAD2()<br />
CaD_PRO_Plus_Datasat21.Loa<wbr />dCAD2()
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<div>
&gt;&gt;When they create a new record the dataset would clear then load to give the latest data so not to get the same number twice.<br />
Thats not going to work either because you will have a concurrency problem.While one user is adding a row to the dataset but it is not yet committed, another user gets the data and begins to add a row. They both will have the same next number.<br />
The way to handle this is to have a sql table in your database, and use an autoincrement identity to supply the id for each new row. Inside your stored procedure that does the insert row you use a transaction. Once the row is inserted, you commit and then select the new row so it and its unique identity (or just select the identity and return it as a scalar if you wish) are returned to your application and update the row in your datatable. No duplicates that way.<br />

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Would it work if I get the number when I save.
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So my thinking is to refresh the datatable and check column (1) for the highest number and add one. This would allow for other users and would be done on save. Some issues<br />
<br />
1. When I refresh like above my record goes to the first record<br />
2. When I refresh will my data be lost before a save? (Maybe save refresh then assign number)<br />
3. What I originally had would give me the next number but always &quot;1&quot; twice
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Checking back to see if you had any progress locking?
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<div class="content wysiwyg-content">
I posted an earlier question which I thought I had the answer and accepted. I use the following code to check for the last number and add 1. The problem I have is the first record is given 1 the next is also given 1 then 2,3,4......<br />
<br />
&nbsp;If Me.CaD_PRO_Plus_Datasat21.<wbr />CAD.Rows.C<wbr />ount = 0 Then<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Me.EventNumberHiddenTextBo<wbr />x.Text = &quot;1&quot;<br />
&nbsp; &nbsp; &nbsp; &nbsp; Else<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Me.EventNumberHiddenTextBo<wbr />x.Text = CaD_PRO_Plus_Datasat21.CAD<wbr />(CaD_PRO_P<wbr />lus_Datasa<wbr />t21.CAD.Ro<wbr />ws.Count - 1)(27)<br />
&nbsp; &nbsp; &nbsp; &nbsp; End If
</div>
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I posted an earlier question which I thought I had the answer and accepted. I use the following code to check for the last number and add 1. The problem I have is the first record is given 1 the next is also given 1 then 2,3,4......

 If Me.CaD_PRO_Plus_Datasat21.CAD.Rows.Count = 0 Then
            Me.EventNumberHiddenTextBox.Text = "1"
        Else
            Me.EventNumberHiddenTextBox.Text = CaD_PRO_Plus_Datasat21.CAD(CaD_PRO_Plus_Datasat21.CAD.Rows.Count - 1)(27)
        End If

Get next number from column in datatable

Visual Basic .NET (VB.NET) is an object-oriented programming language implemented on the .NET framework, but also supported on other platforms such as Mono and Silverlight. Microsoft launched VB.NET as the successor to the Visual Basic language. Though it is similar in syntax to  Visual Basic pre-2002, it is not the same technology,