Get Subset DataTable From Main DataTable, But Preserve Primary Key & RowErrors?
Apr 16, 2012
I came across a problem with using a BindingSource as my DataGridViews.DataSource. Whenever I applied a filter to a column in the BindingSource and the user makes changes that don't match the column filter the DataGridViewRows would automatically disappear. A similar thing would happen when applying a Sort to a column. If the user made any changes the DridGirdViewRows would automatically sort causing rows to be moved around. This was not ideal for my application and there isn't anyway to stop this from happening with the BindingSource.
To correct this issue I have to use subsets of data. I use a DataView to apply the filter and sort to the main DataTable, which creates the subset DataTable.The problem is when I use the DataView.ToTable method I loose the Primary Key and RowError information. So I have to reapply this information everytime the user filters or sorts the DataGridView.Is there a better way to get a subset DataTable?[code]...
I have a function that converts a .csv file to a datatable. One of the columns I am converting is is a field of names that have a comma in them i.e. "Doe, John" when converting the function treats this as 2 seperate fields because of the comma. I need the datatable to hold this as one field Doe, John in the datatable.
Function CSV2DataTable(ByVal filename As String, ByVal sepChar As String) As DataTable Dim reader As System.IO.StreamReader Dim table As New DataTable Dim colAdded As Boolean = False
I'm trying to query a datatable to establish the primary key [identity column], by querying each columns autoincrement property. However its always false (for the column which is the Idenity/PK).
Querying the tables primary key collection reveals that the datatable doesn't think it has a PK.;
Dim dc As DataColumn() = dt.PrimaryKey Debug.WriteLine(dc.Count) 'Result is 0
SELECT T.TABLE_NAME as TableName, T.CONSTRAINT_NAME as CONSTRAINT_NAME, K.COLUMN_NAME as FieldName, K.ORDINAL_POSITION FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS T INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE K ON T.CONSTRAINT_NAME = K.CONSTRAINT_NAME WHERE T.CONSTRAINT_TYPE = 'PRIMARY KEY' AND T.TABLE_NAME = 'mytable' ORDER BY T.TABLE_NAME, K.ORDINAL_POSITION
Query for getting pk of a table. When I Run this query to fill dataset from dataadapter it does not return any value while it returns a row when executed from sql server. Fill method is called correctly as it is working from past 8 months and no problem is yet is there any special property of dataadapter. I also used to put above query in a sp and when try to execute that sp the result was sq not found.
I have imported a single table of a database into a dataset. I would like to find a row containing a specific value and then update some of the data in several columns of that row. When I use the code below, I get this message:"System.Data.MissingPrimaryKeyException: Table doesn't have a primary key."
The first block of code is where I setup my connection and paramters. The updateDB sub is where I want to perform the update. The database was setup in SQL Server. If I have a primary key specified for the database in SQL Server, shouldn't it carry through with the data adapter fill?
I am new at asp.net, so I would be glad, if anybody could help me in this case... I scanned already the internet for answers, unfortunately with no success..I have a grid view, and this is loaded by a sql data table, this table has 2 keys (RezeptNr and Zutatnr). When I wanna update a row in the data grid, the RowUpdating event fires, so I need to read the Basket Session, what has the complete object stored. I put this in a DataTable (dt1), so far so good..The problem is line: Dim dr As System.Data.DataRow = dt1.Rows.Find(id) Here the compiler alerts, that I have two keys, and he cannot select the data sentence with the find method. I tried it with datatable.select command, that works, but then I have the data sentence in an array, but I need to update the data row of the data table.
I am importing Tables from a Oracle DataBase, using a VB.NET dataAdapter. I use the "fill" comand to add the imported data to a DataSet. How is it possible to define a specific column of a DataTable as PrimaryKey, after the DataTable is already filled with data?
Ok so this is going to take some explaining. The process I am trying to do is grab data from a table function in SQL and then fill a dataset with the returned values. I then have to run this query twice more to query an alternative number table. Then add to the same table as the previous queries.This needs to be as fast as possible, so I am currently using an adapter.fill to populate the datasets and then a dataset.merge to put them all into one table.
The problem is the query can return duplicates which waste time and space, because of this I made column 3(part_ID) the primary key to stop duplicates.When this is run with the .merge it quits at the first instance of a duplication and doesn't continue with the population.
I have a datatable and I apply a filter to the defaultview.rowfilter property of that datatable. If I then loop through the rows collection of the datatable, will I only be able to see those rows that the filter applies to, or will it loop through all the rows?
I am working on a project that takes an xml schema and xml data files and places them into a DataTable, the 2 files are generated from a working table that i have written to disk. I wish to load these 2 files into a DataTable. Here is What i have
vb.net Friend Function CreateTable(ByVal tableName As String) As Boolean Dim table As New DataTable(tableName) table.ReadXmlSchema(tableName & ".xsd")
[code]....
this however produces the following error on line 3
Quote:
System.ArgumentException was unhandled Message=DataTable 'get_item_list' does not match to any DataTable in source.
get_item_list is the parameter passed into this function (tableName)
I have a datagridview bound to a datatable setting its datasource property to the datatable. I would like to have a child form that contains a list of columns associated with the datatable that contains a checkbox that will allow the user to hide and show the columns ( I do not know the best control to use here) (I assume this is the easy part as All i need to do is loop through each of the datatable's columns to get the column name)
now I would like save these visible columns on some event like form_closing so that the next time the user opens the form up it will remember the settings
I have a datatable that has a resource in one field and hours used in another, it looks like this -
Resource Hours Used Manager 1 Accountant 1 Field Staff 2 Accountant 3 Manager 4 Manager 1 Administrator 6 Field Staff 4 Manager 0.5 Administrator 1
What I want to do is be able to create a summary of the data table above that groups multiple occurrences of a resource and adds up the hours used for that resource, creating a summary that looks like this -
Resource Hours Used Manager 6.5 Accountant 4 Field Staff 6 Administrator 7
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'm using vb.net 2010.I have a DataSet with a Table and data. MyDataSet1 which contains Table1 I want to create another table that is the same as the Table1 but without data, but it should have the columns, etc.
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 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)
I'm trying to copy one row from DataTable to another, I looked almost everywhere and I can't find a reason why this is happening, I'm using ImportRow and still the New DataTable is empty. Here's one of the answers similar I found and It's still not working!:
Dim newTable As New DataTable Dim dsFrom As New DataTable For Each DBShoes In list Dim iShoeID As Integer
I have an asp.net application where I have a datatable ("DataTableA") that returns just one column ("ProductID").
I want to read each row of "ProductID", process some business logic, then copy both those columns (ProductID & ProductIDBusinessLogicValue) to DataTableB. This DataTableB is then displayed on the asp.net page.
What would bhe the best way to read each row of DataTableA ?
I am updating a data table (dt_report_crypt) from an encrypted csv file in the code below:I decrypt the colums and update the same dreport_crypt, such that it will contain de-crypted data.This part is working wellI however need to use this de-crypted datatable as a data source to update a second table(dt_report), using the sql SELECT command to filter relevant data,
Dim dt_report As DataTable Dim dt_report_crypt As DataTable Using cn As
I have a session which contains a datatable and also have a function which returns a datatable. I need to add these two. How can I do this? The below code is to be replaced with correct code.
Session("Table")=Session("Table")+obj.GetCustomer() where obj is an object of the business layer.
The '+' sign cannot be used to add these two, so how can I do this?
I am finding difficulties to convert a datatable to a new datatable using a reference datatable. My question is confusing and I am not good at explaining things so I drew a picture (see below).I have two datatables on memory and I need to create the third datatable using the second mapping table for reference. The column names are just for example and it can't be hardcoded.
Not certain what exactly I am doing wrong here, but I am having problems in setting a new DataTable (for posting back to the database) to the Changes resulting from the Merge proc of 2 DataTables. The code works fine until I attempt to set the ChangesTable --- it always ends up = Nothing.What is strange is that the "preMergeCount" = 0 and the "postMergeCount" = 23, which is EXACTLY how I expect it to be! So I know that the Merge is working correctly.
Dim sqlTable As DataTable = dsMonitoring.Tables("SQL_SRTraps") Dim exlTable As DataTable = dsMonitoring.Tables("Excel_SRTraps") AddHandler sqlTable.RowChanged, AddressOf Row_Changed
I've got two data tables with store numbers. I need to find out what store numbers are in one data table that arent in another.say one table A might look like:
34, 35, 39
the other table B may be
34, 35, 39, 45
I need to find the 45 If I use nested For Next I can get matches but anything not a match would show up not just the 45 value as the next progresses.
