datacolumn

DataTable DataColumn ColumnName not displaying

由 别来无恙 提交于 2019-12-11 08:03:42
问题 I am new to VSTO and am encountering an issue I can't seem to figure out. I am trying to display a simple table in Excel 2013 and everything populates, except the column display names come out to be "Column1, Column2, Column3". Here is my code: var worksheet = Globals.Sheet1; worksheet.Cells.Clear(); var table = new DataTable("Users"); // Set Columns var columns = new List<DataColumn> { new DataColumn("Staged") { ColumnName = "Staged", Caption = "Staged"}, new DataColumn("FirstName") {

How to find out which Columns are nullable in a DataTable?

由 懵懂的女人 提交于 2019-12-11 07:08:25
问题 Is there a way to find out which columns are nullable in a DataTable? I know that there is a proprety: DataColumn.AllowDBNull, which can be set to true or false in the design mode of the DataSet, but I would like to have this information directly from the database. I am having a DGV populated with values from a MySQL database and have bound the DataSource of the DGV to a DataTable. 回答1: As a solution I decided to retrieve the Columns Schema of the Database and from there assign which Collumns

Button to add entry column to r shiny datatable

由 前提是你 提交于 2019-12-10 11:04:34
问题 I am looking to find a way to add a button to a datatable in r shiny that: Adds an empty column to the data table each time it is clicked (and dataframe that made the table in the first place Which the user can fill himself With numeric or text values And set their own column name to describe the type of entry values. To for instance add lab note records to instrument data that is already in the shiny app manually I am asking in case a more skilled person who has a better clue than me knows

datagridview with datasource and combobox

由 青春壹個敷衍的年華 提交于 2019-12-10 10:27:23
问题 I have a datagridview with a datasource attached to it made of a custom datatable: DataTable: 0 = Dictionary 1 = string 2 = string the datagridview is editable, however for column 0 I need to show a combobox instead of a text field. How do I go about achieving this? internal Dictionary<int, string> products_list = new Dictionary<int, string>(); products_list.Add(0, "Test Product 1"); products_list.Add(1, "Test Product 2"); lines.Columns.Add(new DataColumn("Product", products_list.GetType()));

Add data row to datatable at predefined index

由 ♀尐吖头ヾ 提交于 2019-12-10 05:24:47
问题 I have a datatable with one column: this.callsTable.Columns.Add("Call", typeof(String)); I then want to add a row to that datatable, but want to give a specific index, the commented number is the desired index: this.callsTable.Rows.Add("Legs"); //11 Update: Must be able to handle inputting hundreds of rows with unique indexes. The index must be what is defined by me no matter if there are enough rows in the table or not for the insertat function. 回答1: You can use DataTable.Rows.InsertAt

DataColumn.Expression Power

由 ╄→гoц情女王★ 提交于 2019-12-08 07:55:00
问题 the following code Dim dc = New DataColumn(name, GetType(Double), "[col1] ^ [col2]") produces the following error: The expression contains unsupported operator '^'. Is this right, is the power operand not support in datacolumn expressions??? Anyone have an idea how i'd write this? 回答1: Yes. it is not supported. You could use RowChanging event of DataTable to set the value of the new column using c#. 来源： https://stackoverflow.com/questions/982754/datacolumn-expression-power

changing values of a column in datatable in vb.net

由 孤街醉人 提交于 2019-12-07 23:46:09
问题 I want to loop through a databale and change the values of a specific column in that datatable. eg: the database returns Request_ID , Desc , Date and Status_Ind . The Status_Ind column contains integer values. I dont want to show the integer values to the user. I want to convert that to a string value based on the integer values returned in that columns. if Status_Ind = 1 then 'the values changes to Published 回答1: You could do it by creating another column: Dim dt As New DataTable dt.Columns

DataColumn's AutoIncrement Returns False Always

由 谁说胖子不能爱 提交于 2019-12-07 18:56:56
问题 I am interested to check out whether column has an autoincrement/allowdbnull property . Having this code below , gives me always false although I already have one column that has autoincrement/allowdbnull property. Dim dt As New DataTable() Dim con As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source =" & Application.StartupPath & "\test.mdb" Dim sql As String = "SELECT * from teachers" Dim i As Integer Dim dataAdapter As New OleDb.OleDbDataAdapter(sql, con) dataAdapter.Fill(dt)

DataColumn's AutoIncrement Returns False Always

由 荒凉一梦 提交于 2019-12-06 14:21:12
I am interested to check out whether column has an autoincrement/allowdbnull property . Having this code below , gives me always false although I already have one column that has autoincrement/allowdbnull property. Dim dt As New DataTable() Dim con As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source =" & Application.StartupPath & "\test.mdb" Dim sql As String = "SELECT * from teachers" Dim i As Integer Dim dataAdapter As New OleDb.OleDbDataAdapter(sql, con) dataAdapter.Fill(dt) dataAdapter.Dispose() For Each column As DataColumn In dt.Columns TextBox1.Text = TextBox1.Text & column

Button to add entry column to r shiny datatable

由 不问归期 提交于 2019-12-06 09:11:27
I am looking to find a way to add a button to a datatable in r shiny that: Adds an empty column to the data table each time it is clicked (and dataframe that made the table in the first place Which the user can fill himself With numeric or text values And set their own column name to describe the type of entry values. To for instance add lab note records to instrument data that is already in the shiny app manually I am asking in case a more skilled person who has a better clue than me knows how to do this. I have read a bunch of pages, but at best the example I found provides 1 fixed empty
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