Change DataType Of Datatable Columns?
Sep 7, 2011I want to change the DataType of all columns of DataTable. I don't want use the loop.. [URL]
View 6 RepliesI want to change the DataType of all columns of DataTable. I don't want use the loop.. [URL]
View 6 RepliesI have a datatable which has a number of rows containing dataThen I need to add some empty datacolumns which I do like this:
Code:
Dim OT_Hours As New DataColumn("OT_Hours")
OT_Hours.DataType = System.Type.GetType("System.Double")
[code].....
I have a datatable that I read xml into.
One of the columns is a date, but the dataype of that column is set to string. Is it possible to change that dataype to date?
anything wrong with using datatype object and determine datatype in class property? I have a typed dataset and it has several integers columns that are null in the db. and when I make a call it throws exception.is there anythign wrong with setting it as object in my dataset.. changing the throw exception property to Nothing and passing it to my property as integer?
for each row in myDS.DataTable
cRate.CustID = row.CustID
next row
and in my class
Public Property CustID() As Integer
Get
Return _custID[code].............
I have a window application created in VB.net 2005 and the backend is sql. I make a call to the database and it returns a datatable. When I loop through it, I get a value of -1 for my field "Rush" which is a bit datatype. when I pass the sql into the analyzer, I see the value should be a 1 so not sure why it's giving me a -1. Here's some of the code that's in the page: Dim tblSendEmail As DataTable
tblSendEmail = oService.GetSendEmailInfo 'Goes to a webservice and returns a record set in the datatable
For Each row As DataRow In tblSendEmail.Rows
iRush = row("rush")
next
[Code]...
Following is the code which gets xml data from web service and then dataset reads using ReadXml method. This Xml has ID and MyDate tags for each table row (so table(0) will have ID and MyDate columns) and this Xml data does not have schema associated with it. When page is loaded first time, it sorts by ID in asc order. It was working until ID was 999. When next ID came as 1000, even in ID asc, 1000 is showing before 999 in datagrid.
I wanted to confirm that when dataset is loaded using ReadXml, all the columns in its table are treated as string even they are numbers or dates and that's why in ID asc order 1000 is coming before 999.
Also, MyDate tag has date in format "01/31/2011" (mm/dd/yyyy) and it seems that sorting is wroking fine for date. Would sorting by date always work even when dataset table MyDate column is of type string (assuming that my above statement is correct)? Are my two above assumptions correct?
stream = New System.IO.StringReader(XML data returned from web service)
With dataset
.ReadXml(stream)
dvView = .Tables(0).DefaultView
[code]...
Is there a simple way to assign a populated datatable's columns to another empty datatable? That is, I want to copy a datatable's structure only but not its data.
View 6 RepliesI have a query to retrieve DateDiff in my SQL:
SELECT Convert(char,DATEDIFF(m, Temp.Opening_Date, '2011-05-01')) As MonthDifference From Temp
It was successfully retrieve the data from SQL Server. But when I bind it to my vb.net datatable, the value is null. It's seems like vb.net datatable doesn't support datatype from DateDiff... What can I do?
I have a DataTable that has a hierarchyid data type column pulled from SQL Server. Is it possible to use the column to easily populate a treeview object in Visual Studio 2008?
View 7 RepliesI have this code that use to sort a datatable.
Dim sortingIndex As Integer = orderby
Dim DataTableNew As DataTable = New DataTable
DataTableNew = dt.Clone
Dim query = (From c In dt.AsEnumerable Order By c.Field(Of String)(sortingIndex) Ascending)
query.CopyToDataTable(DataTableNew, LoadOption.OverwriteChanges)
My problem is that with this method I always need (Of String) for it to work, so the date columns are also managed as Strings witch is the problem. Is there a way to use the correct type so the sorting is based on the type of the column?
I pull a report from SQL Server being not a fan of cursors I process that table server side in my code behind file. So I pull this report that is an address label report and my client wants there to be X number of labels per person. So I coded this function:
Private Function ProcessX(ByVal dt As DataTable, ByVal X As Integer) As DataTable
Dim dtProcessed As DataTable = dt.Copy
dtProcessed.Clear()
[code].....
I have a datatable property called prpParametersTable in a class called clsBatch. I have a procedure that sets a datatable variable called dtP equal to prpParametersTable at the beginning of the procedure. I then add three new columns to dtP.Here is my problem. When I add the three new columns to dtP my original table prpParametersTable also gets those columns added to it, why? I only want to add the three columns to dtP and not prpParametersTable. How can I do that?
Private Function prvfnc_InsertBatchParameters(ByRef cnn As SqlConnection, ByRef trans As SqlTransaction) As String
' set new columns that have BatchID, Insert DateTime, and UserID for the SQLBulkCopy method below
Dim clm As DataColumn
Dim dtP As DataTable = clsBatch.prpParametersTable
[code]....
I'm converting a asp.net application from .NET 2.0 to .NET 3.5 I have loads of inline code like so:
Dim Total = 0
for each dr as DataRow in dt.Rows
Total = Total + dr("SumOfAmount")
next
Response.Write(FormatCurrency(Total,2))
Notice that there is no explicit type declaration of the total variable.This code worked fine under .NET 2.0 Under .NET 3.5, the Total variable is defined as an Integer, therefore the total is being rounded to the nearest dollar on every pass.I know one solution is just to change
Dim Total = 0
to either
Dim Total as decimal = 0
or
Dim Total = 0D
However I'd prefer to not have to visit every page in the system looking for this problem.Is there any site wide, or page wide option I can set the change this behavior back to the way it was under .NET 2.0?
Is there a way to change a base class type by Overrides or Shadows, or other meen?[code]...
In this example there is MyBaseClasswitch is the base Class, then ClassB that Inherits from MyBaseClass, and In ClassB I try to overrides the base property "MyColl" to change is type to a enum.
But it do not work, telling me that the base collection cannot convert to eCarBrand, blah blah blah
Is there other way to change base class type or other approach that a could use?
how to change column into checkbox with datatype of Boolean?
View 3 Replies
I have a VS2005 utility that I'm working on that has an Access 2003 backend. A couple of days ago, my boss asked that I change one field in two tables from TEXT to MEMO, to allow more information to be put in. In doing some final pre-deployment testing, I find when I hit my button to pull up the list of tickets, I get the error
"System.Data.ConstraintException was unhandled
Message="Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints.""
The datagrid is based on a query I have in the database. The query runs fine, and when I go through the XSD and go into Query Builder, the QB is also returning data. I have made the various changes to the utlity as suggested by Microsoft, but no luck. When I put the two columns back to TEXT, the Grid works fine.
How the heck do I set it up so that the grid will recognise the new data format? The number of characters for the individual columns is set to 37,627 (I believe, it's whatever the default is). I only have 200 characters in my test data. I need to rebuild the whole dataset - this deployment has to be done by the end of the day tomorrow and I have a whole pile of other stuff left to do.
i have a datagridview table ("Bookingen") that is bound to an acces datatable
this table ("Bookingen") has columns
an i also have another form that alows people to add info like a registerform
what i would like is that when adding the info by button click
a column with the name of the person from registerform displayes in datagridview ("booking")
this my code so far
Public Class nieuw_personeel_invoer_code_
Private stroledb As String = "SELECT* FROM Loginnummer"
Private strconnection As String = "provider= Microsoft.ACE.OLEDB.12.0; Data Source=D:clifs project21.accdb; persist security Info=false;"
[Code].....
How can I get a sum for all the columns in a datatable? Say I had the following table. How can I calculate the "total" row? It should be easy to add total row to a datatable.
Columns hits uniques sigups, etc...
Rows
1 12 1 23
2 1 0 5
[Code].....
I have a DataTable oDT. oDT is populated from SQL Server with 6 columns including a column "bAAA" of varbinary(200) I have a function fx(ByVal byteArray As Byte()) as String I would like to add a calculated column to oDT something like this:
oDT.Columns.Add("sAAA", GetType(String), fx(bAAA))
'bAAA is not declared
oDT.Columns.Add("sAAA", GetType(String), fx("bAAA".ToArray))
[Code].....
Since now, I have the following:
vb
Dim x = ( _
(From row In _Obj_DataSet.Tables(TableName).Rows() _
[code]....
I fill a data table with 11 columns and 1 row.
Columns/ User Pass
Row / **User2054** 1234
I have a Label named lblUser and I want to put the value=User2054 from my Table(Collumn[0], Rows[0]). How I can fill it?
I currently have a datagridview that is built from a datatable So lets say we have 6 columns
A B C D E G
So the users will select there data from another program and paste into the the table. So lets assume that the data that is pasted is; (the column names are automatically put in)
A B C D E G
123 456 789 101 112 134
So the table will now look like following (I remove the first row because its the same as the column name)
A B C D E G
A B C D E G
123 456 789 101 112 134
My problem is that the users can rearrange thier tables(column index) so lets say user A has the table in this format
A B D E C G
123 456 101 112 789 134
So when they paste into the program, it will look like
A B C D E G
A B D E C G
123 456 101 112 789 134
So now "C" "D" "E" are incorrect and i need to swap those columns to be the same as the column name. I'm not sure how to attack this problem.My thoughts were to paste the data as is, than see what the first row in each column equals.so if it equals "A" assign it an index 0
B 1
C 2
This seems theres too many steps and will slow down the app...
I have a Datatable- table1 and i want to sort/order this datatable in ascending order depending on 2 columns-column0,column1 of table1. how can i do that?
View 2 RepliesI have a Datatable- table1 and i want to sort/order this datatable in ascending order depending on 2 columns-column0 ,column1 of table1.how can i do that?
View 2 RepliesI have one datatable. In that table I have columns named [Total Day], [Present day], and [leave].
Data are as follows:
[Total Day], [Present day], [leave]
30 25 5
30 26 4
Now i want to concatenate those three columns in one another column. I want output something like this:
[Total Day] [Present Day] [Leave] [TotalDay PresentDay Leave]
30 25 5 30 VBCrLf 25 VBCrLf 5
30 26 4 30 VBCrLf 26 VBCrLf 4
I have list of columns in DataTable to be added in list view. I have specified to the listview of columns in the order to appear and Datas as well.[code]
View 1 RepliesIs there a way to add columns in a datatable to the intellisense of the datatable? Is there a way to display the columns of a datatable in a datagridview?
View 5 RepliesQuestion: I'm exporting a System.Data.DataTable to XML.So far it works fine.But I want to have all the data in attributes, which works fine as well.But my problem now, if in one column, all rows are NULL, no empty attributes are written.So if I read the XML back to a DataTable, it lacks this column...How can I force write all columns even when they are empty ?(DataType not necessarely string)
public void ExportTable(string strDirectory, DataTable dtt)
{
using (System.Data.DataSet ds = new System.Data.DataSet()) {[code].....
I have a scenario where-in I have a DataTable with certain columns "Col1, Col2, Col3". I want to copy just "Col2, Col3" into another DataTable which has a primary key "ID". What is the best way to copy them. There are 5000+ records and performance is a key factor.I tried with Select, DefaultView.RowsFilter but no success. I know one option is to loop through all records an copy data one by one in second DataTable. But wanted to know a better way.
View 1 RepliesThis doesn't seem like something that should be confusing or difficult, but I'm having a hard time finding the answer to this problem. I want to copy columns with their data, not rows, from one large DataTable to a smaller one.I have a DataTable with many columns of data (around 20), and a string array of the columns (4 ) that I want in the copied DataTable. Is there a reasonable way to accomplish this task?
View 1 Replies