VS 2008 - How To Create Array From DataTable Columns
May 18, 2011
I have a Datatable consisting of columns with Latitude and longitude I want to be able to pass through each of those values in each row into an array that can then be passed through a function which gets the distance between each row and a static. In short I am trying to get distance between one location and various others that reside in a datatable that will vary in size. Right now with this existing code I am getting 6 different locations into an array:
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Public Function GetCoords() As Coord()
Dim myCoords() As Coord
myCoords(0).Lat1 = CDbl(list1_Lat.Text)
myCoords(0).Lon1 = CDbl(List1_Lon.Text)
[Code] .....
If I am on the right track I think I need to create a new array that will accept Lat and Lon from each row in my Datatable? My end goal is to be able to find properties within a certain distance of a property. In other words "return all properties that are within .25 miles of 12 Maple Street". I thought if I had Lat and Lon of a certain property there would be a formula that would give me the max and min Lat and Lon to be within a .25 mile radius. I have searched for how to get a radius, but didnt come up with anything I could comprehend. So instead I thought I would just get each properties (row) return the distance in a new column then loop through the table to return properties within the desired distance .25 miles etc...
I want to select column 'F1' from an excel spreadsheet and dump the data into my datatable 'oleDT'. How do I map the column F1 to the column i've added called 'colTest' ? When i call Fill, the dataTable has 2 columns, which are 'colTest' full of nulls and a created column called F1.[code]...
I am trying to program a noise reduction algorithm that works with a set of datapoints in a VB.NET DataTable after being helped with my other question. Basically, I want to take two integers, a coordinate value (yCoord for example) and a threshold smoothing value (NoiseThresh), and take the average of the values in the range of (yCoord - NoiseThresh, yCoord + NoiseThresh) and store that number into an array. I'd repeat that process for each column (in this example) and end up with a one-dimensional array of average values. My questions are:
1) Did anything I just say make any sense ;), and
2) Can anyone help me with the code? I've got very little experience working with databases.
I know how to create an array and loop through it normally - but what if I need a multi-column array. e.g. usually I might do something like:
For Each row in NameofArray Dim name as String = row Response.Write("Hello " & name & "!") Next
But what if I want to do something like:
For Each row in NameofArray Dim name as String = row.name Dim age as Integer = row.age Response.Write("Hello " & name & "! You are " & age & " years old!" Next
I have text file that is saved as comma delimited. There are 3 columns with x number of rows. I cannot seem to figure out how to create an array that will store all three columns with the variable intProductArray as the length of the array. I have been opening the file with only one column and putting it into a textbox and using the lines of the textbox as the variable for length. I cannot figure out the array for all 3 columns.
Private Sub btnChoose_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnChoose.Click Dim myFileDlog As New OpenFileDialog() myFileDlog.InitialDirectory = "c:" myFileDlog.Filter = "All Files (*.*)|*.*" & _ [Code] .....
I have set up a series of loops to construct a series of tables dynamically using a cloned table. Each table represents the output for a particular year. These work fine and create the correct output. However, I want to put the total of a particular column in these tables into textboxs on my form.
When adding a column to a datatable. I can specify a type as one of my overloads such as
dt.Columns.Add(New DataColumn("UID", Type.GetType("System.Int32")))Why can't I use
dt.Columns.Add("etwe", TypeOf(Integer)) when I thought integer is a type. Instead its telling me that integer is a type and can't be used as an expression.
I need to build an interface that allows the user to select a horse from a list. The horses are as follows: horse1, horse2, horse3 and horse4. The application should display the way the horse places with a 1 means the horse won, 2 indicates second place , 3 indicates third and 0 indicates the horse did not place. Application needs to display a summary of each horse's individual performance as well as the performances of the other horses. Table for keeping track of each horse is as follows:
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.
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
This related to another question I have below that I beleive can be solved several different ways, this question is more specific to filling an array from a Datatable my DataTable has columns "Latitude" and "Longitude"From my message box I inserted to try and debug I seem to be just getting a -1. When i break point at the myCoords line it says there are 100 which is coorect there are 100 rows in my table. I know I am mising something stupid but being new I am unable to see my error.Also dont have the correct syntax for the debug.WriteLine Here is what I have so far:
I am trying to add the returned values from an array to the rows in a data table: Here is my current code the values load properly into the list box but not the table, each row ends up with the same value.
current code not working correctly Dim dtrow As DataRow Dim lat As Double = CDbl(34.213209)
i've created a new access 2007 database + added a OLE Object field, that i've then pasted images into.
in vb2008 i've connected to the database + put the table into a datatable. so far it works ok.
when i try to convert the byte array to an image, it causes an error:
'A first chance exception of type 'System.ArgumentException' occurred in System.Drawing.dll'
heres the code i'm using:
vb
Dim arr() As Byte = DirectCast(record.Item(5), Byte()) pic.Image = Image.FromStream(New IO.MemoryStream(arr))
its loading the byte array properly, but the Image.FromStream line causes the error. i've used this method before with an earlier access database + it works.
Now, I want to place the rows from foundrows into an empty data table.I did what I thought was the obvious but that only returns a bunch of rows with no data
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;"
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.
I have a table with 2 rows named timeStamp and value. I know I can iterate through the rows and create points and add them to a list (new point(timeStamp,value), but is there a way to do it without iteration?
My code is crap, so I don't really think it will be useful because I've been going about it differently than I really want to:[code]..... I really don't wanna be loading a file in, I just wanna use XMLDocument() to create a file from my DataTable.But, my file ain't coming out right and I'm sorta just lost as to how this is all supposed to fit together.
Ok, what I would like to be able to do seems simple enough. I would like to be able to create an Excel document with a series of columns that contain data to import into Visual Basic 2008
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))
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?
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?
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]
Is 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?
Question: 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].....
