How to update columns in datatable using linq without conditions. I have an idea that I'm just gonna loop all the data in the datatable but don't know what comes in LINQ.
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I have a datatable as shown in the figure. Let me explain my required based on this image. I have 7 rows of data. The rows 1 and 2 contains columns till UnitSqcNo same. I want only row 3 among the two. In general I want select all the rows with distinct model, unittype, unit and rest with greater CompId. ie the table should look like
View 1 Repliesdiscovered the compact mode of this instructions vs usual code. I found sample code for selecting, etc. from a datatable, transforming a column in a list or array - all operations are "Select"s - readonly.I need to make an simple update on a certain rows (using LINQ) from a DISCONNECTED datatable for which now I'm using this
for each dr as datarow in dtable.Rows
dr("MyField") = 77
next
[code].....
I am pretty new to using LINQ and have been trying it out querying my strongly typed DataTable.
I have managed to perform a 'Select' ok but was wondering if someone can point me in the right direction to do Insert and Updates. I'm not sure if LINQ is best doing an insert at all?
My Select code is as follows:
Dim results = From myRow In _dt.AsEnumerable() _
Where myRow.Language_key = Lang And _
myRow.Section_key = SectionKey And _
[Code]....
I am trying to distinct on multiple columns and get datarows from datatable. but getting error.
Dim query As IEnumerable(Of DataRow) =
(From row As DataRow In SourceTable.AsEnumerable() _
Select row.Field(Of String)("ColumnName1"),
[Code]....
I want another datatable with distinct row based on given columns from SourceTable.
I'm using a loop condition to check if there is null value in the columns, then remove it.
-Original author
[STart:]
For i As Integer = counter To dt1.Columns.Count - 1
For x As Integer = 0 To dt1.Rows.Count - 1
if some condition then
something = true
[Code]...
Sometimes it runs correctly and sometimes even though when i becomes greater than (dt.columns.count - 1), it still executes the for loop and throws an error that there is no column with that index. I must be missing something here but I'm not able to debug the issue.
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 RepliesWhats wrong with the below query, I am getting this error: Nullable object must have a value.
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I want to filter records dynamically on user choice. The user may choose to show the debit amount greater than credit or credit amount greater than debit. Accordingly I want to put a condition similar to either totDebit>totCredit orTotCredit>totDebit`
Dim query = _
From product In Bills.AsEnumerable() _
Group product By accode = product.Field(Of String)("ACCODE"), _
[Code]....
I've populated my DataTable will all the results from a SQL search. Upon a button click I want to populate a combobox with all the results where a condition is met. My DataTable as a column called UserID and I want to add all results where the UserID is equal to a set value (for example 12). I can do this to add all results and I guess I could add a if statement inside this to be If Entry.Tag = 12 Then but is there a better way?
[Code]...
I'm basically trying to emulate a query like the below in LINQ:
DECLARE @id INT
SET @id = 1
SELECT
q.txtLQRdisplayName AS DisplayName,
[code]....
I have a requirement where I have to add items into a List(Of T) (let's call it Target) from an IEnumerable(Of T) (let's call it Source) using Target.AddRange() in VB.NET.
Target.AddRange(Source.TakeWhie(Function(X, Index) ?))
The ? part is a tricky condition that is something like: As long as the as yet unenumerated count is not equal to what is needed to fill the list to the minimum required then randomly decide if the current item should be taken, otherwise take the item.Somethig like...
Source.Count() - Index = _minimum_required - _curr_count_of_items_taken _
OrElse GetRandomNumberBetween1And100() <= _probability_this_item_is_taken
' _minimum_required and _probability_this_item_is_taken are constants
The confounding part is that _curr_count_of_items_taken needs to be incremented each time the TakeWhile statement is satisfied. How would I go about doing that? I'm also open to a solution that uses any other LINQ methods (Aggregate, Where, etc.) instead of TakeWhile.If all else fails then I will go back to using a good old for-loop =)
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 want to make condition to update my table if there's already same data (in the same column) inserted in the table.[code]...
View 2 RepliesI 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
[code].....
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 RepliesPublic Sub UpdateStaff(ByVal sr As StaffRecord)
Dim oldSr As StaffRecord
Dim q = From staff In db.StaffRecords Where staff.Employee_Number = sr.Employee_Number Select staff
oldSr = q.First
oldSr.Address_Line1 = sr.Address_Line1
[Code]...
The helper function I have written seems to do everything I want apart from update the db. Stepping through the code, the oldSr is updated by the new sr parameter but no update on submit changes.
I 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 want to change the DataType of all columns of DataTable. I don't want use the loop.. [URL]
View 6 RepliesI 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.
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