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I have a form that displays data from a specific table from a data set. I want the form to display the data from a specific row in that table. I have manipulated the table adapter, the data set and the table in every way I can think of to no avail. How do I get the table to display that specific row?
Can you please explain your set up further and show us you code ?
Sure. I have a form that has text boxes to display a set of fields on the form. I can change the data in the fields and save the data if I desire. In the load sub I use the following code to fill the form:
Me.TblFMFileMasterBaseTableAdapter.Fill(Me._MasterBase_03DataSet.tblFMFileMasterBase)
This puts the data from the first row into the form. What I want to do is display a specific row instead of the first row.
Also, I use this form elsewhere and have a binding navigator for that usage. However, for this usage I have set the visible property for the binding navigator to false, since I only want the one record to display.
If you have a BindingSource bound to the DataTable then you'd set the Filter property to the correct filter. The correct filter all depends on the column name, how you wish to compare the data, and the value being compared. For example, if I had the following DataTable:
ID First Name Last Name 1 John Doe 2 Jane Doe 3 David Day 4 John McIlhinney 5 Jacob Roman
And if I wanted to return all rows where the last name column is Doe then the BindingSource's filter would be:
Notice the single quotes around the search value, this is important.Code:BindingSource.Filter = "Last Name = 'Doe'"
The above will give you a value for each specified column from your dataset by replacing your column name with the name of the column you wish to get the value fromCode:Me._MasterBase_03DataSet.tblFMFileMasterBase.rows(0).item ("yourcolumnname").value
Then simply set your text box. Text property equal to this value
I used both methods suggested above and got an unhandled exception error. I assume that the value in the quotes (both methods) is the table column name and not the text box name? I already have the value for the row held in a variable so all I want to do is plug that value into the code and display that record. I apparently am still not getting it.
Can you show the line in which the exception occurs?
You would have to change "BindingSource" with the actual name of the BindingSource.Quote:
I used both methods suggested above and got an unhandled exception error.
In my example, the value of the filter should be in the following format:Quote:
I assume that the value in the quotes (both methods) is the table column name and not the text box name?
So if you had a TextBox that was representing your value then the code would need to be tweeked:Code:Column_Name Comparison Value
Code:BindingSource.Filter = String.Format("{0} = '{1}'", "ColumnName", TextBox.Text)
Sure. I tried both of the following (individually) and in each case they threw the same exception. The second one, seems to me, that it would provide the value of the row, which I already have. What I want is to take the ROWNUM value and use it to display the record in that row instead of the first record in the table.
Me.TblFMFileMasterBaseBindingSource.Filter = "intFileID = ROWNUM"
Me._MasterBase_03DataSet.tblFMFileMasterBase.Rows(ROWNUM).Item("intFileID").Value()
I am about to take a shot at the binding source filter
Your code takes the value your giving and gives it back to you ? You've filtered by the itnfileid column and then returned the value of that column so we you find your exception you will still not have exactly what you want I would presume ?
However your error is that you have included your variable within the speech marks so it won't take the value of your variable it will treat it as a string which cannot be used to filter an numeric field which is the cause of your exception
I don't think so. What I have when the form loads is the first record on display. What I want to display is record at ROWNUM
Use the last code snippet from dday this should stop your exception occurring
OK, Here is what I did
In the form load sub I have the following code:
Me.TblFMFileMasterBaseTableAdapter.Fill(Me._MasterBase_03DataSet.tblFMFileMasterBase)
Me.TblFMFileMasterBaseBindingSource.Filter = "intFileID" = ROWNUM
And here is the exception that is thrown on the second line above:
An unhandled exception of type 'System.InvalidCastException' occurred in Microsoft.VisualBasic.dll
Additional information: Conversion from string "intFileID" to type 'Double' is not valid.
intFileID is an integer field from the table and ROWNUM is an integer variable set to a specific integer value. Where does type double come into this?
Use the last code snippet from dday this should stop your exception occurring
OK, here is what I did with the code
Me.TblFMFileMasterBaseBindingSource.Filter = String.Format("{0} = {1}", "intFileID", txtFileID.Text)
What I got was the record from the first row is displayed. intFileID is the field in the table and txtFileID is the text box on the form. I then changed the values in the squiggle parenthesis, but got an error for my effort. Where in there do I define the row that I want to display the record for?
Where it says rows() you place the row number in between the brackets
ok, i placed the following code snippets in the form load event
Me.TblFMFileMasterBaseTableAdapter.Fill(Me._MasterBase_03DataSet.tblFMFileMasterBase)
Me.TblFMFileMasterBaseBindingSource.Filter = "intFileID = 5"
So then the data for record number 5 is displayed. However, if I use the integer variable ROWNUM in the place of the integer value, I get the following exception:
'System.Data.EvaluateException' occurred in System.Data.dll
Additional information: Cannot find column [ROWNUM].
Now why will the integer variable ROWNUM work instead of an actual integer value? I am getting a headache.
Where it says rows() you place the row number in between the brackets
Take a look at this example and see if you're able to get a better understanding of how the filter property works:
Code:Public Class Form1
Dim bs As BindingSource
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
'Create the DataTable and add 3 columns
'ID: Int32
'First_Name: String
'Last_Name: String
Dim dt As DataTable = New DataTable("MyTable")
dt.Columns.AddRange({New DataColumn("ID", GetType(Integer)), New DataColumn("First_Name"), New DataColumn("Last_Name")})
'Create 3 new DataRows from the DataTable
'Set their cell values
'Add them to the DataTable
Dim row1, row2, row3 As DataRow
row1 = dt.NewRow()
row1(0) = 1
row1(1) = "John"
row1(2) = "Doe"
dt.Rows.Add(row1)
row2 = dt.NewRow()
row1(0) = 2
row1(1) = "Jane"
row1(2) = "Doe"
dt.Rows.Add(row2)
row3 = dt.NewRow()
row1(0) = 3
row1(1) = "David"
row1(2) = "Day"
dt.Rows.Add(row3)
'Create a BindingSource and set it's DataSource as the DataTable
bs = New BindingSource With {.DataSource = dt}
'Create a DataGridView and set it's DataSource to the BindingSource
Dim dgv As DataGridView = New DataGridView With {.DataSource = bs, .Dock = Fill}
'Create a TextBox. This will be the value we want to filter.
Dim txtFilter As TextBox = New TextBox With {.Dock = Top}
'Add the Controls to the Form
Me.Controls.AddRange({txtFilter, dgv})
'Generate the TextChanged event for the TextBox
AddHandler txtFilter.TextChanged, AddressOf txtFilter_TextChanged
End Sub
Private Sub txtFilter_TextChanged(ByVal sender As Object, ByVal e As EventArgs)
'Get the TextBox
Dim txtFilter As TextBox = DirectCast(sender, TextBox)
'Check if the value is not empty
If Not String.IsNullOrWhiteSpace(txtFilter.Text) Then
'Set the filter to the text and compare it to the Last_Name columns
bs.Filter = String.Format("Last_Name = '{0}'", txtFilter.Text)
End If
End Sub
End Class
You have me confused Leary. It does not say rows() in there anywhere. Which code snippet are you referring to?
I used the one in the form load event from DDay that goes:
Me.TblFMFileMasterBaseBindingSource.Filter = "intFileID = 5"
and it opened the form displaying the record from row #5. However, when I substituted the integer variable ROWNUM for the integer value 5 I got the following error:
System.Data.EvaluateException' occurred in System.Data.dll
Additional information: Cannot find column [ROWNUM].
So the only question is how can I get the number that I want into that code snippet since I cannot seem to use the integer variable ROWNUM
If you know the index of the row you want to display, simply set the bindingsource.position property. For example, if you want to display row#5 which has the index of 4 (because indexes are zero-based), you'd do:Quote:
Originally Posted by gwboolean
Code:Me.TblFMFileMasterBaseBindingSource.Position= 4
Perfect! I did have to reduce the variable by 1, but that gets the job done. Obviously I need to learn how to explain myself and what I am trying to do better in the future. Thanks a lot!