In vb.net 2008, how can I display table column names in a combobox?
In SQL I have a Document table and there are columns in this table like Doc_id, Size, Path.
The combobox must display the columns name like
doc_id in the first line, size in the second line, path in the last line
Probably a little too late since I see this thing is about eight years old, but I just ran into this issue where I had to do exactly what the initial questioner was asking for. Since I resolved it, I will leave it here just incase another poor sap like us comes along looking for answers
'VB.net
Dim ds As DataSet = <define your dataset here>
Dim dt As DataTable = ds.Tables(<Your tablename here>)
For Each column As DataColumn In dt.Columns
combobox1.Items.Add(column.ColumnName)
Next
As per our discussion , i will suggest you not to bind the combobox directly with the DataTalble. you can bind it by looping all the row of the DataTable. you use following snipped as a reference:
Dim objDataTable As DataTable = ds.Tables("Document")
IF objDataTable <> NULL Then
For j As Integer = 0 To objDataTable.Rows.Count
Dim str As String = objDataTable.Rows(j)("Doc_id").ToString()
comboBox1.Items.Add(str)
str = objDataTable.Rows(j)("Size").ToString()
comboBox1.Items.Add(str)
str = objDataTable.Rows(j)("Path").ToString()
comboBox1.Items.Add(str)
Next
END IF
Hope this will work for you ;)
Related
I have a Query qryRuleSets which outputs a table with 19 fields (that I do not want to save into an access table before that is suggested). I would like to get the field names and store them into an array so I can use that array in a for loop later on.
To find the number of fields that in the query result (to use in for loop later on) I have implemented the following, where the number of fields is stored in the variable numberfields -
numberfields = CurrentDb.QueryDefs("qryrulesets").Fields.Count
To actually get the name of these fields and store them in an array I am running into 2 problems:
1. Getting the field names from the query result
2. Setting up a dynamic array so that if the query ends up returning a table with more or less than 19 fields, it will still work
For my first problem:
I have tried to follow the steps in the following link: Get Column name from a query table but I can't figure it out.
To get the field names from the qry result I have tried the following but I'm not overly knowledgeable in vba/access so finding it hard to understand, even after a whole lot of googling:
Dim qry As QueryDef
Dim fieldNames As QueryDef
Dim firstcol As String
Set fieldNames = CurrentDb.CreateQueryDef(qry.qryrulesets)
firstcol = fieldNames.field(0).Name
For my second problem:
To store values in an array I have tried the following (as a test) and it works but I have to define the size of the array. Is there a way where it can be dynamic, i.e based on the value of the number of fields (found above stored in numberfields) :
Dim vardata(30) As Variant
For i = 1 To numberfields
vardata(i) = "hello"
Next i
I tried making the '30' above to a variable value but it didn't like that.
Any and all help will be appreciated. Thanks!
You can do like this:
Public Function GetFieldNames(ByVal QueryName As String) As String()
Dim Query As DAO.QueryDef
Dim FieldNames() As String
Dim Index As Integer
Set Query = CurrentDb.QueryDefs(QueryName)
ReDim FieldNames(0 To Query.Fields.Count - 1)
For Index = LBound(FieldNames) To UBound(FieldNames)
FieldNames(Index) = Query.Fields(Index).Name
Next
GetFieldNames = FieldNames()
End Function
i have user below code to clear the cell value of a datagridview column.
For Each item As DataGridViewRow In dgvGeometricImport.Rows
item.Cells("Status1").Value = String.Empty
Next
Do we have any short cut to clear all value without iterating the rows?
can we use linq to achieve this?
thanks in advance
With or without a DataSource set, you can *remove and re-add the column.
VB Example with DataSource set:
Dim index As Integer = Me.dataGridView1.Columns("Status1").DisplayIndex
Dim table As DataTable = DirectCast(Me.dataGridView1.DataSource, DataTable)
Dim column As DataColumn = table.Columns("Status1")
table.Columns.Remove(column)
table.Columns.Add(column)
Me.dataGridView1.Columns("Status1").DisplayIndex = index
VB Example without DataSource set:
Dim index As Integer = Me.dataGridView1.Columns("Status1").Index
Dim column As DataGridViewColumn = Me.dataGridView1.Columns("Status1")
Me.dataGridView1.Columns.Remove(column)
Me.dataGridView1.Columns.Insert(index, column)
*Disclaimer: This will work, but if I'm being honest I can't say for certain that there's no iteration occurring at some lower level. After all, when you re-add the column it becomes a part of each row entry and therefore could have been iterated through under-the-hood.
One approach would be to use jQuery selectors. It would of course still iterate through the rows, but it would be done client side and behind the scene.
$('#' + gridViewCtlId + ' td:nth-child(' + INDEX_COLUMN_TO_CLEAR + ')').html('');
use this :
dataGridView.Rows.Cast(Of DataGridViewRow).ToList.ForEach(Sub(r) r.Cells("ColumnName").Value = String.Empty)
but it's the same thing, linq will do the iteration
I have a SQL database with a table "Employees" in it (with large number of rows). By using DataGridView, I want to search for specific "Employee's Name" and change it's "Job". How can I achieve that. I'm using VB.net. Please Help Me.
Not sure if this will help but write a loop that goes through all the values if it finds a match its true if not it is false ,if found the item can be displayed in a textbox and edited
if not a message is displayed saying "no match found"
the editing part can be done using a procedure that will update the value in your grid with what is entered
i can supply code for this if need be but i am unsure if this is what you wish
and there is most likely a better way of doing it
you can loop through your grid, and check if the data you wish to edit exists using the For loop:
Supposing you are using a textbox as the input, and you use a label to hold the employee ID:
Dim EmpIDColumn as Integer = 'array number of your EmpID Column
Dim EmpNameColumn as Integer = 'The array number of the column where your EmpName is
Dim JobColumn as Integer = 'The array number of your job column
For each dr as Datagridviewrow in Datagridview1.Rows
If dr.cells(EmpNameColumn).value = TxtSearchBox.text Then
txtEmpJob.text = dr.cells(JobColumn).value
lblEmpID.Text = dr.cells(EmpIDColumn).value
End if
Next
Okay, so you've searched the record successfully. Next step (after editing the job, and even other details like the name) would be to update the record in the grid. Remember you set the lblEmpID's text to empID in the column? Use it to find the
Record you wish to change in the grid using the same technique above!
Dim EmpIDColumn as Integer = 'array number of your EmpID Column
Dim EmpNameColumn as Integer = 'The array number of the column where your EmpName is
Dim JobColumn as Integer = 'The array number of your job column
For each dr as Datagridviewrow in Datagridview1.Rows
If dr.cells(EmpIDColumn).value = lblEmpID.text Then
dr.cells(JobColumn).value = txtEmpJob.text
dr.cells(EmpNameColumn).value = txtEmpName.text
'then, type in here your SQL Query Update!
End if
Next
I have a datatable that contains the rows of a database table. This table has a primary key formed by 2 columns.
The components are assigned this way: datatable -> bindingsource -> datagridview. What I want is to search a specific row (based on the primary key) to select it on the grid. I cant use the bindingsource.Find method because you only can use one column.
I have access to the datatable, so I do manually search on the datatable, but how can I get bindingsource row position based on the datatable row? Or there is another way to solve this?
Im using Visual Studio 2005, VB.NET.
I am attempting to add an answer for this 2-year old question. One way to solve this is by appending this code after the UpdateAll method(of SaveItem_Click):
Me.YourDataSet.Tables("YourTable").Rows(YourBindingSource.Position).Item("YourColumn") = "YourNewValue"
Then call another UpdateAll method.
Well, I end up iterating using bindingsource.List and bindingsource.Item. I didnt know but these properties contains the data of the datatable applying the filter and sorting.
Dim value1 As String = "Juan"
Dim value2 As String = "Perez"
For i As Integer = 0 To bsData.Count - 1
Dim row As DataRowView = bsData.Item(i)
If row("Column1") = value1 AndAlso row("Column2") = value2 Then
bsData.Position = i
Return
End If
Next
I have the following code:
Dim i As Integer = dtResult.Rows.Count
For i = 0 To dtResult.Rows.Count Step 1
strVerse = blHelper.Highlight(dtResult.Rows(i).ToString, s)
' syntax error here
dtResult.Rows(i) = strVerse
Next
I want to add a strVerse to the current row.
What am I doing wrong?
The problem you're running into is that you're trying to replace an entire row object. That is not allowed by the DataTable API. Instead you have to update the values in the columns of a row object. Or add a new row to the collection.
To update the column of a particular row you can access it by name or index. For instance you could write the following code to update the column "Foo" to be the value strVerse
dtResult.Rows(i)("Foo") = strVerse
You can access columns by index, by name and some other ways:
dtResult.Rows(i)("columnName") = strVerse
You should probably make sure your DataTable has some columns first...
Dim myRow() As Data.DataRow
myRow = dt.Select("MyColumnName = 'SomeColumnTitle'")
myRow(0)("SomeOtherColumnTitle") = strValue
Code above instantiates a DataRow. Where "dt" is a DataTable, you get a row by selecting any column (I know, sounds backwards). Then you can then set the value of whatever row you want (I chose the first row, or "myRow(0)"), for whatever column you want.