Join Two Datatables From Different Datasets?
Mar 10, 2010How To Join Two Datatables From Different Datasets (With One Commn Column) ???
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Datatables Left Join Linq - Joining 2 Datatables And Have The Joined Datatable As Result
Jun 1, 2012I'm having a hard time joining 2 datatables and have the joined datatable as result. First datatable (labels) holds data including a printerid. Second datatable (printers) holds printer references (id > unc). I would like to have as endresult (joined) a datatable with all data from the first datatable with the field (unc) of the second datatable. [Code]
View 3 RepliesJoin Two Datatables Into One?
May 28, 2012I have two datatables which I intends to bind them to Gridview. But I need bit of the first dt and bit from second dt.
Second table has only one row that represents to every row in the same column in first table.
There is no primary key or relationship between two tables though.
For example,
I tried datatable.merge though. Didn't produce the last table i want.
Database Logic - Differences Between Datasets And Datatables ?
Jan 12, 2009My understanding of databases (access and sql) is fairly limited, though i have got a couple of programs under my belt using access databases, not yet used SQL. I could however, work around to figure out a way to do what i'm trying. What i don't understand is the need for all of the components, so all i'm after is somebody who can take the time to fully explain these further to me, or point me in the direction of somewhere i can gather a full understanding.
My questions are, for now;
1. Why do we need to take a copy of the database, rather than dealing exactly with the database itself?
2. What differences are there between datasets and datatables, what is better for what and why?
3. What is the purpose of the data adapter?
How To Join Two Datasets Together
Aug 2, 2011how to join two datasets together.
First Dataset
Dim sql As String
sql = "SELECT payment.Debtor, SUM(Value_invoice) AS before_this_month,debtor.nama FROM Payment INNER JOIN dbo.debtor ON Payment.Debtor = debtor.debtor" & _
[code]....
Now i just want to either inner join or left join PaymentBeforeThisMonth and PaymentThisMonth into another dataset?
Join Datatables For Local Reporting
Aug 15, 2011I don't know how to join multiple datatables created in Designer in 1 single Datatable. I need 1 Datatable with all data in it so I can give that single Datatable to one single Tablix in ReportViewer (rdlc). Problem: ReportViewer Tablix can accept only one datatable at time and I need them all at once in one tablix.
How did I get stuck here:* I have added Dataset from Solution Explorer to my Project (ds1). Double click on that item gave me Dataset Designer (ds1.xsd). Here I have created 4 Datatables with all needed columns, mutually connected with parent-child relationships (one to many, nested). dt1 is parent to dt2, dt2 is parent to dt3, dt3 is parent to dt4 (dt1 > dt2 > dt3 > dt4).
On my forms I have binded all my controls to this 4 Datatables and their respective columns so the data is populated hierarchically to dataset (as planed). I have added ReportViewer Control to one form for reporting purposes and Design a new report (rdlc)...As I have read in past few days (read: week or two) I need to Join all my datatables to one single (flated) datatable somehow and then feed that DataTable to my Report.
So basically I have 2 questions: 1. How to join my 4 datatables? Can I do it from Designer or I must do it in code? 2. If I cant do joining from Designer how will I see this new datatable with all columns from my Report? If I wanna add a Dataset/DataTable to my Report I go to Tab Report Data - New - Dataset - comboTo SelectExistingDatasets and if Datatable/Dataset is not created in Designer I can not see it here to add it to work with it.
Use LINQ To Left Join 2 Datatables?
Nov 10, 2011I have two UNTYPED datatables: "Shelfs" and "Books". Data came from different databases.
I must create a "left join" relationship because I want a list of ALL shelfs and books (if they have any).
Dim dset As New DataSet
dset.Tables.Add(dtShelfs)
dset.Tables.Add(dtBooks)
[Code].....
I spent hours googling around, but all examples I found were only applicable to strongly typed dataSets, and how to build queries (not to get the data)
I could solve this the "easy" way: by looping both datatables and sending the rows to a third one, but I want to do this the "right" way and, of course... LINQ exists to make things easier and I don't know how to use it
Join Multiple Datatables Using LINQ To Dataset?
Feb 8, 2012I have been searching for quite a while about joining multiple datatables via LINQ to dataset (When i say multiple, i don't mean just 2!!!), and it seems there aren't lot of examples in the net. I have seen examples of joining two datatables, done that, no problem there. Now i want to join three datatables. And there's nothing i can find out there.For example i have a 3 datatables:
PERSON (columns: person_id, name, gender_code, ethnic_code)
GENDER (columns: gender_code, gender_description)
ETHNICITY (cols: ethnic_code, ethnic_description)
[code].....
Join Datasets - Program To Catalog MP3s
Apr 30, 2010I'm working on a program to catalog MP3s (I know, it's a tired thing that's been done to death), and want a better way to determine if a file has previously been added to my database. I have two datasets that are structurally identical. The first dataset is populated from the database and the second is populated via the application during the scan.
I then compare each record in the second dataset to the first with the following code:
Private Sub CompareDataSets(ByVal dsOriginal, ByVal dsNew)
Dim dv As DataView
Dim sFileName As String
Dim sPath As String
Dim bgFileSize As Long
[CODE]...
This method seems terribly inefficient and I'd much prefer being able to do a join of sorts off the two datasets and delete all records from the application populated dataset where there is a match.
Inner Join - Join Two Tables,'Employee' And 'Dispatch'
May 17, 2012Iwant to join two tables,'Employee' and 'Dispatch'. Dispatch has column 'DispatcherID' and 'TechnicianID' which are both foregn keys to EmployeeID in Employee table.I want to join these two tables using EmployeeID so that i can obtain the matching name to each id.but it only works when i make a single join to either DispatcherID or TechnicianID and not for both.
[code]
select Employee.firstname+' '+Employee,secondname as Technician,Employee.firstname+' '+Employee.secondname as Dispatcher from Dispatch inner join Employee on Dispatch.TechnicianID=Employee.EmployeeID inner join Employee on
[CODE]...
Add Datatables Via Openfiledialog?
Nov 11, 2011I'm trying to the contents of a datatable to a datatable thats allready in my form using the openfiledialog.[code]...
View 4 RepliesBest Way To Merge Datatables?
Apr 12, 2010I'm trying to create a program that will merge two data tables (one from a database on a network drive, the other is found in a database on the local machine). Each datatable is identical in structure, only (maybe) differs in content. The structure has a primary key, dateCreated, and dateLastEdited fields (plus other fields). I would like to merge down from the network to the local database. If the primary key does not exist on the local db but does on the network, copy from the network db to the local table. If it does exist, check the dateLastEdited column and copy the latest row to the local table.
How would i set up the code to do this? Any assistance would be great.
How To Intersect Two DataTables
Jan 23, 2012How to intersect two dataTables in vb.net 2.0? I want to get common rows in two datatables and add it in third datatable.
View 1 RepliesHow To Merge Two Datatables
May 20, 2012I need to marge two datatables with condition. I have a datatable where the data comes from a local XML Database and another datatable where the data comes from a remote SQL Server. If any update made in the remote datatable I need to update/merge with the local datatable. Here is what I have so far:
Public Sub MargeTwoTable()
Dim SQL As String = ""
Dim RemoteTable As New DataTable
Dim LocalTable As DataTable
[code]....
In this code data comes from the remote database which updates a date getter then the local database . Both tables have "ID" as the primary key. The code is working well, but the problem is that when more than 1000 records are updated this function takes too long using loops.
Merging Two DataTables?
Jun 7, 2012I have a Main Table that contains all the distinct values in a DataTable.DataColumn. also have a Child Table that contains distinct values created by the user.I want to merge the Child Table DataRows that match on the Value column with theMain Table DataRows to create the New Table (shown below).I want to preserve the values in the Selected column of the Child Table.Here is my problem, if I use the DataTable.Merge method the DataRow that contains "888" in the Child Table is added to the New Table, but it doesn't contain a RowState = Added, thus I can't filter for added rows to remove them.
View 4 RepliesOne DataGridView Two Datatables
Jun 10, 2010I am using VB Express 2008 and SQL Server Express 2008.I have one DataGridView on a Windows Form, which I am attempting to populate from two datatables. Both tables are identical in structure, but with data from two different dates. The respective SELECT statements are identical, except for the date; one calls for yesterday, one for today. I need a seperate Sum column from each table.I've tried to JOIN, UNION, and MERGE the tables, but that gives me all the data consecutively and I saw no way to seperate the days. I'm able to add DataColumns, and sum the fields with an expression, but is it possible to create DGV columns and bind them to the seperate DataTable columns? [code]
View 6 RepliesQuery Two Datatables In .net?
Mar 19, 2012I am stuck with an issue.I have two datatables, with the same table structure, i need to select data from table1 such that the records arent existing in table2is it possible to do this in vb.net? if yes then how?
Table1(AAno,Agencyname,location)
Table2(AAno,Agencyname,location)
Criteria:Select AAno,Agencyname,location from table1,table2 where table1.AAno<>table2.AAno
SQL Statement With DataTables
Oct 12, 2011I'm stumped trying to do an equivalent SQL statement in VB 2010 working with two DataTables, & am hoping someone could point me in the right dirction.I currently have two data tables with three fields each :- A, B, C. The data in field A is the same in both tables & could be used to join the two tables.How could I input data into a third data table having data from both primary tables ? Something along the lines of the following SQL code.[code]
View 3 RepliesUsing Checkboxes In Datatables?
Jan 18, 2012I have a datatable with a yes/no checkbox in it and when I filter my datasource it loads form2. Right now I'm using this code to have a label's color as green if it's checked and red if it isn't:
Private Sub Customers2BindingSource_CurrentChanged(sender As Object, e As System.EventArgs) Handles Customers2BindingSource.CurrentChanged
If ActiveCheckBox.Checked = True Then
Label1.Text = "Active"
[code].....
That works when I do something like bindingsource.movenext because it's in the bindingsource_currentchanged event, but when I try adding that to the form_load it's automatically set to Inactive, color red. I figured it's because is set to checked = false, but what event do I use to make this work when the form loads?
What's the value of a checked checkbox for the update/delete/insert commands? Like dates are DateDateTimePicker.Value.Date. Is it something like this?
.AddWithValue("@Active", ActiveCheckBox.Checked)
I don't use checkboxes to often.
Combining DataTables Using Linq
Apr 27, 2012I've seen several posts on the subject, but none seem to answer this particular dilemma. I have two datatables that I obtained by querying two separate servers.[code]
View 7 RepliesComparison Syntax Between Two Datatables?
Mar 23, 2009I am trying to compare two datatables and generate a resultant datatable of rows that do not match based on customer number. The main table "Customers" contains all customers that have been placed in our system. I am trying to generate a table of customers, "dtResults," that we have not ever generated an invoice from a table called "CurrentCust".I would like someone to look at the attached code and see how I can handle the 'InvalidCastException was unhandled', 'Unable to cast object of type 'System.String' to type 'CustomerDataTable' error. Error occurs at line 43.
1
Option Explicit On
2
Option Strict Off
[code]....
Copy/Mege Of DataTables?
Jun 11, 2012using VB.net 2010 using DataAdapter and DataTables I'm trying to merge two datatables together and update a database with the results if I use the following code it works (though not ideal):
For Each tRow As DataRow In excelDt.Rows
accessDt.Rows.Add(tRow.Item(0))
Next
however if I use the following I don't get a error, it just doesn't update:
accessDt.Merge(excelDt)
accessDt.AcceptChanges()
For ease here I named the DataTables to describe where they are coming from. accessDt is a empty DataTable (to start) from a Temp Access database table with 1 or more columns in it and excelDt is a DataTable created from a Excel Worksheet with the same columns (same order as well) as the Access Table. Basically just trying to get the data from Excel into Access. They are using the same update command just swapping out which method is commented out. I have checked and accessDt does have the data in it before the Update is called using both methods.
Create Program Datatables From SQL TVP?
Jun 28, 2010I am in the process of revising code to use TVP to send data from our VB.NET app to the SQL 2008 DB and try to keep all the writes atomic.[url]...
I am in the process of creating all the in-code datatables to be sent to the SQL stored procedure
However, I will have to create these datatables and datacolumns (then add the columns to the tables) repeatedly for multiple tables.
Data Transfer Between DataTables ?
Jun 14, 2011I have a sequence that reads the selected Excel-file and displays the first row of the columns in the Excel. (The first Excel row has the column names)
Dim cmd As OleDbCommand = New OleDbCommand("select * from [" & tableName & "$]", MyConnection)
Dim dr As System.Data.IDataReader
Dim dt As New System.Data.DataTable
dr = cmd.ExecuteReader
dt.Load(dr)
With the above code I can read the the first rows of the Excel table and choose the names of the columns I like to keep. (By populating the first row to my ComboBoxes)
So, at the moment my DataTable dt has all the table header names but on the first row. And as the header names it has F1, F2, F3, ... F13.
How can I make my new DataTable dt2 take the first row of dt and make it the column names row? How can I choose which columns do I want to transfer from dt to dt2 ???
I have tried the following (Doesn't work):
Dim dt2 As System.Data.DataTable
dt2 = dt.Copy.Columns("F1", "F2", "F3", "F4")
DataGridView1.DataSource = dt2
Datatables And Screen Painting?
Dec 2, 2010Their system executes a DB query everytime they select something, causing performance issues. So I thought that I would read the superset of data into a datatable, and then whenever they want subsets, simply run against the datatable. I've done some testing and the performance difference is HUGE.The problem is how the screen paints on postbacks. The screen will temporarily go blank then the data will appear as expected. Of course, they don't want the blanking of the screen each time they select a subset of data.
I am currently using a repeater to handle the display of data due to the nature of what they want to display. A datagrid might be a good alternative for sorting functions, but I think it would still blank the screen when it data binds.How do I go about filling the repeater without blanking the screen? Is it even p[ossible? Logically I would think not but I don't have the experience. Or perhaps I can fill a datagrid without blanking the screen on the postback?I'd rather not have to go out to the database every time, but if that's the way to go then I can live with that.
Datatables And Xml Reading - Fail
Jan 7, 2010I am working on a mdi project and I have a few different xml files that I need to read in and I would really like to use multiple datatables, but only one dataset. I have always struggled to get a datatable.readxml(filename) call to work without an invalidoperationexception b/c of the schema stuff. I don't understand it very well and in the past my workaround was just to make another dataset. I am trying to avoid doing that from now on. I have written a routine called readxml which will take a xml file name, xml schema file name, and a datatable name and return to you a populated datatable..but I can't get it to work.
Here is my call to the read xml method (comes from my main mdi form class during form load)
Dim dt As DataTable = globals.xml.readxml("SqlConnectionString.xml", "SqlConnectionString.xsd", "sqlConnection")
Here is my readxml routine, I will post two versions of what I tried attempt #1: use a string of raw xml and a xmlreader
[CODE]...
Filter Datatables In Memory?
May 4, 2011I just discovered that ODBC and OLEDB drivers I need to use do not support Access nested queryDefs. The database I was given is full of many layers of nested queryDefs. Is there any way I can build the tables in memory from simple query defs and then use those tables in subsequent querys?
View 8 RepliesMerging DataTables With Different Columns?
Jun 22, 2010I have an access 2007 Database where I store several different "Jobs" such as repair job, data recovery job etc.
At the min I have a form where the user can view a customer's related jobs either by type, or all jobs related to the customer. I'm trying to do this by adding each job type to it's own DataTable, then merging the DataTables into one.
Private Sub rdoShowAllJobs_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rdoShowAllJobs.CheckedChanged
'####################### Procedure Level Constants and Variables ###########################
' Dim dtDataRecoveryJobs As New DataTable
[Code]....
What I want is for the first column, ID, to contain the primary key from each table, but when the code runs it adds each primary key column from the tables to the end of the AllJobs DataTable! Am I trying to do something impossible here or is there a way around this?
Querying From Multiple Datatables?
Nov 25, 2010I am trying to create a stock scanner which allows users to filter stocks based on multiple criteria that they select. Like the following example with 2 criteria:
Criteria 1 Filtered Result: StockA, StockB, StockC, StockD
Criteria 2 Filtered Result: Stock B, Stock C, StockE, StockF
SCANNER RESULT: Stock B, StockC (ideally this result would be displayed in a GridView)
[code]......
Reset One Of The Datatables Within Dataset
Jul 20, 2011I've added a column to one of the tables in the database. Is there a quick to reset one of the datatables within my dataset so that I do not have to delete the whole datatable and add it back in?
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