Possible To Fill A Collection-Type Instead Of A DataTable/DataSet?
Aug 4, 2010
this is more a theoretical question i asked myself.I remembered that BinarySearch of an ordered List(Collection in general) is faster than finding Rows with Datatable.Rows.Find or DataTable.FindByPK with a primary key value.Hence i fill a Datatable from Database in a shared constructor and immediately after that a List(of Int32) that contains all primary keys from that table. Later i will check with BinarySearch if the List contains primary-key values. But because the datatable contains only the PK-Column anyway, i asked myself if there is a way to avoid the huge overhead of filling a Datatable and after that adding all Rows to a List. Is it possible to fill a generic List(or other collection-type) instead of a Datatable/Dataset directly from a Dataadapter?Maybe i'm off the track and there is another way to avoid the Extra-Loop that i'm missing.
The code of filling the DataTable in a strong typed Dataset and the List:
Private Shared w205CorrectSWUpgrades As New List(Of Int32)
Shared Sub New()
[code].....
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Jan 16, 2010
I want to add a new select command to my dataset. To do that, I have added a new partial class to my project. Because we have to use partial class if we want to extend generated dataset codes. [code]...
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Jan 6, 2010
fill a NEW DataSet's DataTable with data from a DataGridView? I am generating a data report that uses that "new DataSet." I need to go from a DataGridView to a DataSet because i need the person to be able to perhaps edit the information before its inserted into the report. my process to generate the report is...
- fill datagridview with advanced join sql
- allow user to edit datagrid if necessary
- put datagrids modified information in new dataset
- set report's databinding source to new dataset
- generate report...
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Jul 8, 2010
I have recently started .NET programming, and looked at both VB.NET and C#. In VB.NET, a strongly typed Datatable cosisted of a collection of strongly types rows. Therefore, for example, this statement would work:
lCustomerTable As CustomerDataSet.CustomerTable
lCustomerRow as CustomerDataSet.CustomerTable.CustomerRow
lCustomerTable = TableAdapter.GetData
lCustomerRow = lCustomerTable.Rows(0)
However in C#, it seems i have to explicitly cast the returned Row to a CustomerRow:
lCustomerRow = (CustomerDataSet.CustomerTable.CustomerRow)lCustomerTable.Rows[0]
Should the dataset not create the object type definitions when creating the table adapters and SQL dataTables?
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Dec 30, 2009
I am trying to export a dataset to a csv file
VB
Private Sub ExportDatasetToCsv(ByVal MyDataSet As DataSet)
Dim str As New StringBuilder
For Each dr As DataRow In MyDataSet
[code]....
I am getting an error on this line: For Each dr As DataRow In MyDataSet The error is Expression is of type 'System.Data.DataSet', which is not a collection type.
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Aug 6, 2010
I am trying to add NewRow to the database by using datatable in dataset, but before I do that I want to make sure that row is not already there. I create new row for the datatable I am working with, fill it with information. I fill datatable with the row from database that has the same primary key as my NewRow by using tableadapter.fill method, but when I do that my NewRow that was never added to the datatable is filled with information from database(and not information that I assigned to it). I count rows in my datatable before I fill it and it's 0, so why is my NewRow affected by Fill command? (I am using VB.NET 2005 Framework 2.0)
[Code]....
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May 14, 2012
I have tried everything I can to get beyond this error which shows below as <<<<< error here. It is trying to fill a dataset from a data adapter. If I change the SELECT statement to just SELECT * FROM xTable I get the correct number of records in each table. But anytime I try with a more complex statement I get the error message shown below which indicates System.Data.Common.DbDataAdapter.Fill(DataSet dataSet. I've completely erased all data and entered a new set of test data so I know there is no problem with relationships. Each table has primary key which is foreign key in other table. IS there something wrong with the Imports section: Imports System
[Code]...
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Jun 5, 2010
I need to pick all data in my application from my database and use it in my form
my question : how to pick all data in my application then i use it
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Mar 15, 2010
When the user clicks an "Edit" button on my form, I want a box to come up which allows the user to edit a DataTable in a strongly-typed DataSet. What's the best way to do this?
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Jan 28, 2010
I have code running in the Datatable.ColumnChanging event in my dataset. This dataset underlies a form and conventional drag/drop controls are in place for data entry.when the event triggers and runs, I am running code in the form that checks the dataset.HasChanges property. It is showing False. But this is immediately after the ColumnChanging event has been triggered.Okay, I see by others posts and MSDN that .HasChanges will only be true after moving off the row with the changed column. I have also noted lots of discussion about the advanced binding property of DataSourceUpdate Mode, but that does not address this issue.I guess I can do this by checking the state of the row for the binding source. Just seems odd that the event behind the dataset can be triggered and that does not change the dataset.HasChanges property.
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Oct 31, 2010
how to copy data from datatable to table in dataset i ry this but its readonly property
ds.datatable1=newdt.copy
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Jan 6, 2012
I can't seem to get a DataTable filled.url...I'm using VB, Visual Studio 2010.I keep getting an error on this line: adapter.Fill(dt)The Microsoft Jet database engine could not find the object 'Book1.txt'.Make sure the object exists and that you spell its name and the path name correctly.The name of the file and the path should be perfectly fine, although i did change the code just a bit:[code]I read somewhere that you have to 'drag a data adapter object from the Toolbox onto a form or component'.I don't have a DataAdapter in my Toolbox.I did a right-click and selected 'Choose Items.It is nowhere on the .NET Framework Components.
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Aug 24, 2010
i am trying to copy data from a standard Dataset to a Type Dataset (XSD) of same table structure. i want to use Automapper to do that one. So how can i do that using automapper?
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Apr 22, 2010
I am writing a program that needs to read a set of records that describe the register map of a device I need to communicate with. Each record will have a handfull of fields that describe the properties of each register. I don't really need to edit or modify the data in my VB or C# program, though I would like to be able to display the data on a grid. I would like to store the data in a CSV file, or perhaps an XML file. I need to enable users to edit the data off-line, preferably in excel.
I am considering using a DataTable or a Collection of "Register" objects (which I would define). I prototyped a DataTable, and found I can read/write XML easily using the built in methods and I can easily bind to a DataGridView. I was not able to find a way to retreive info on a single register without using a query that returns a collection of rows, even though I defined a unique primaty key column. The syntax to get a value from a column is also complex, though I could be missing something on both counts.
[Code]....
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Aug 25, 2010
i want to fill a Datatable with a Datareader row by row but get an exception because the reader's columns have a different order than the Datatable's columns.
Why and how does a Datatable loads itself with a Datareader correctly, even so it has a column collection with different order?
I need to calculate values for every row so i dont want to load the Datatable completely but row for row. It has 25 columns so i dont want to set it all manually.
There must be a chance to load/fill/add a new row from a datareader without having the same column order(reader.GetSchemaTable?).
Following is what i have but what doesnt work:
Using reader As System.Data.SqlClient.SqlDataReader = command.ExecuteReader
'next line works(configInfo.DataSource is a Datatable)but is inappropriate
configInfo.DataSource.Load(reader)
[Code].....
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Feb 23, 2010
I am using a SQL query to fill a datatable from 2 associated tables. The first table has Products and the second has associated addonpackages. When I loop through my Products I am able to get all of the addonpackages for the first product but after that the datatable is only getting populated with the last addonpackage for each product. ie:
product 1 - all 6 packages are added tp the datatable
product 2 - only package 6 is added to the datatable
product 3 - only package 6 is added to the datatable
...and so on
My query follows. Why I am getting all of the info for the first product but just the last item for all others. No matter which product I would query first, I get all of the associated data with it but only the last for all others.
SELECT Products.ProductNumber, Products.Name, Products.Mnemonic, AddOnPackages.PackageNumber,
AddOnPackages.Name AS PackName, AddOnPackages.Mnemonic AS PackMnem
FROM AddOnPackages RIGHT OUTER JOIN
Products ON AddOnPackages.ProductNumber = Products.ProductNumber
WHERE (Products.Name = @ProdName)
ORDER BY Products.ProductNumber, AddOnPackages.PackageNumber
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Dec 30, 2011
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?
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Feb 13, 2009
I want to fill a combobox with the values that I have in a datatable. How can I do that? Below is the code for the population of the datatable:
[Code]...
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Aug 16, 2011
I would like the main form I am designing in VB.net to appear as quickly as possible. As a result I don't want to fill a datatable in the load event but instead fill it as soon as the form appears, in the background.Then when a user clicks the button a listbox can quickly be populated.
With this in mind I called a function to fill the datable from the _Shown event. The trouble is that the form freezes until the query executes, making the process pointless for my needs.
Does anyone know how to keep the form active while the datatable fills silently in the background?
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Mar 28, 2012
I have a table like this
col1 col2 col3
a b
c d
I want to fill the 3rd columns.
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Jun 1, 2012
I'm getting a set of data by a datareader and assigning to a string. Now I need to fill the datatable columns with the Query fields. The datatable is connected to a grid to display the filled data.
query is : strSQL = "SELECT EmpCode,EmpID,EmpName FROM dbo.Employee"
Datatable columns are EmpCode,EmpID,EmpName.
I need to read the query and assigned to the columns of datatable and fill the table.
Me.DtShifts.Tables("NonAllocated").Clear()
Me.DtShifts.Tables("NonAllocated").Load(dr)
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Aug 8, 2011
Aim to Achieve : I want to have 3 different dataTables from 3 different SQL queries from 3 different places into 1 single DataSet which I will have to return form my function.I have :
Private Function getDataSet()
Dim ad1,ad2,ad3 As Object
ad1 = New Data.OleDb.OleDbDataAdapter(query1, conStr1)[code].....
I want to use the best possible implementation of above task.
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Feb 9, 2012
I have a need to assign values from my dataset to a variable but when i use string (which its normally text) and the item in that row of the dataset is empty it tells me that conversion from DBnull to string is not valid
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Aug 9, 2011
i encounter this error while passing a string as datatable.
I populate combobox1 with tables/sheets from excel and each table has datarows which i want to get the data and import to sql corresponding table, so, I declare
Dim XLSTableName as String = Combobox1.SelectedItem
And I encounter the this error : Conversion from type 'DataTable' to type 'String' is not valid
how do i return the combobox1.SelectedItem as Datatable cos if i declare
Dim XLSTableName as DataTable and pass it to the select Command thus:
Dim objCmdSelect As New OleDbCommand("SELECT * FROM [" & XLSTableName & "], ODBConn)
to obtain the dataRows I got the following error: operator '&' is not defined for types 'String' and System.Data.DataTable'
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Apr 12, 2011
I was wondering if there is a way to change the Fill command text of a datatable before issuing it.I need this because the table I am opening has over 15 thousand rows and it hangs for a while in the network when filling the table. So I would like to tell it what to SELECT instead of getting the whole table and then applying a filter.If there's a way of doing that without changing the fill command, it will also work for me.
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Jun 5, 2011
I'm trying to create a Server/Client Sync scenario for my application using Sync Services for ADO.NET specifically the LocalCache custom tool which sets the whole thing up for me.My server DB has 5 Tables, all of which are being synchronized to the client application, which now has a SQL Server Compact DB with the same schema as the server DB. I have a dataset with some custom queries that I use to connect my app with the local database.So far so good.However in my application when I try to fill one of my tables with the table adapter on my form (the default "fill" method) it gives me the following exception:No mapping exists from DbType Object to a known SqlDbType.
However, if I continue and do the fill again, IT WORKS without a problem.
Try
Me.WTSUsersTableAdapter.Fill(Me.WTSMainDataSet.WTSUsers)
[code]......
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Apr 20, 2012
I have a SQL db that holds the records for my page. On my page I have a details view I want to populate with records from my db. I can populate the records just fine, I need to be able to populate in records based on a user selection from a drop box?To clarify, on my main page I have a drop down list with years (ie. 2011, 2010, 2009), and a drop down containing account codes (ie. six-digit numbers). Based on what the user chooses for the year (for example 2010) and the what they choose for the account code (for example 123456) I want to populate the details view (which is on a seperate page) with only those records from 2010 and with the account code 123456??
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May 28, 2010
The following code loops through the rows of a datatable to process each record which has a Processed column value not equal to -1. When a record is processed, its Processed value is updated to -1. As a record is processed, the code within the Do Loop may add a new record to the datatable with a Processed column value equl to 0. All of that works as intended. My test set record gets processed and a new record is added.At the end of the For.Next code, there is a line , "clsWTAdapter.Fill(clsWTDataTable)", which I intended to refresh the rows so that it would include the newly added record which would then be processed during the next iteration of the For...Next sequence. This is not happening. What am I doing wrong, and how can I refresh the rows and process the newly added records?
I found this line in an MSDN page about DbDataAdapter Fill Method (DataTable) at [URL]"The overload of Fill that takes DataTable as a parameter only obtains the first result. Use an overload of Fill that takes DataSet as a parameter to obtain multiple results."Does this mean that I am on the wrong trackby using a datatable where I should be using a dataset? Does "multiple results" mean filling the dataset multiple times like I am trying to do with the datatable?
Using clsCnn As New SqlClient.SqlConnection("Server=REXSQLEXPRESS;Database=dmf;Trusted_Connection=True;")
clsCnn.Open()
Dim clsCmd As New SqlClient.SqlCommand
[code].....
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Nov 11, 2010
I have a datatable that was created with the dataset designer. I have it bound to my datagridview. All the columns are set up the way I want, etc. I am performing a SQL operation at runtime, so I can create SQL statements dynamically rather than creating them with the designer. When I try to fill the existing datatable, I get no results. There is no error, but the data i should be seeing in the DGV is not there. However, if I fill a dataset that is created in code at runtime, and then set table(0) of that dataset as the DGV's datasource, the data displays as it should.
[Code]...
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Jan 26, 2011
It seems I've tried a million little variations of this and I keep getting the same error: "The SelectCommand property has not been initialized before calling 'Fill'
Imports System.Data
Imports MySql.Data.MySqlClient
Public Class clsDB
[code]....
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