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by: Peter |
last post by:
Hi, I have two datatables and I want to efficiently query the
intersection of the two using the studentID. In my example code below,
I want to print out Mary and Jane and their exam grades and I don't
want to use loop because the real datatables are much larger. Can this
be done using one of the inbuilt methods in the class library and if
so how.
Thank you in advance
Peter
DataTable examgrade;
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by: Bennett Haselton |
last post by:
If I have just filled a DataTable in a typed DataSet with a single
row, is there a way I can make a copy of that row, so that I can clear
the DataTable in that DataSet and use it for another query, but my
copy of the row will be preserved?
If I try to do something like this:
this.oleDbWbuserAdapter.SelectCommand.CommandText =
"SELECT * FROM wbuser where username='bennett';";
this.oleDbWbuserAdapter.Fill(ds1.wbuser);
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by: Danny Ni |
last post by:
Hi,
If I want to programatically add rows to a DataTable, do I call
AcceptChanges per row? Or do I call AcceptChanges after all rows added?
TIA
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by: Flack |
last post by:
I have pasted at the end of this message a small sample program I whipped up
to do some testing.
It's a form with a datagrid and two buttons. Each button clears the
dataTable that is the source of the dataGrid, and then adds five rows.
Button2 is the same as button1 just that it does this in a different thread
(I was testing if I was having some threading issues).
Anyway, it seems that the location of the call to dt.Rows.Clear()...
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by: Adrian Parker |
last post by:
We've suddenly started getting a problem with a call to clear the contents
of a DataTable. This is on a live customer site that's been working fine
until yesterday. As far as we know they've not changed or updated the
server in any way.
"There is no row at position 42"
at System.Data.RBTree`1.GetNodeByIndex(int32 userIndex)
at System.Data.DataTable.Clear(Boolean clearAll)
at system.Data.DataTable.Clear()
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by: nil |
last post by:
Help me.i am new to vb.net and i am developing one web application in
vb.net2003.
I am facing many problems in that so i would like to tell you one of
them.
I hope i will have the good response and advice.
problem is like this
I Want to store data temporarily so i create one datatable in coding
and each time when user
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by: cj |
last post by:
I have a program to display queries to a SQL db. I type my query in a
textbox and click a button and the results display in a datagrid. I
could use either dataset or datatable to read the data in then I make
the datagrid.datasource = myds.Tables(0) or mydt. Now what I want is to
be able to change the query and click the button again and get the new
results. I can use clear() to clear the data from a ds/dt but I need
the structure gone...
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by: XenReborn |
last post by:
Ok this should be simple.
I made a form, added a combobox (for selecting items to edit, not for updating fields), several textboxes, a few checkboxes etc. On formshow it connects to my database, draws down the existing data, no problem. All the records in the datatable that were the result of a query, I could select from, and the other databound components would display the records contents, no problem..... however.... when i add a new row, the...
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by: =?Utf-8?B?anAybXNmdA==?= |
last post by:
I've got a routine that builds a table using different queries, different SQL
Tables, and adding custom fields.
It takes a while to run (20 - 45 seconds) so I wrote a thread to handle the
table population.
Whenever I call the thread, I pass it a structure containing the table and a
few other parameters. The table goes in as a reference, but the other items
are passed normally.
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by: marktang |
last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However, people are often confused as to whether an ONU can Work As a Router. In this blog post, we’ll explore What is ONU, What Is Router, ONU & Router’s main usage, and What is the difference between ONU and Router. Let’s take a closer look !
Part I. Meaning of...
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by: Hystou |
last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can effortlessly switch the default language on Windows 10 without reinstalling. I'll walk you through it.
First, let's disable language synchronization. With a Microsoft account, language settings sync across devices. To prevent any complications,...
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by: Oralloy |
last post by:
Hello folks,
I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>".
The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed.
This is as boiled down as I can make it.
Here is my compilation command:
g++-12 -std=c++20 -Wnarrowing bit_field.cpp
Here is the code in...
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by: tracyyun |
last post by:
Dear forum friends,
With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
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by: agi2029 |
last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing, and deployment—without human intervention. Imagine an AI that can take a project description, break it down, write the code, debug it, and then launch it, all on its own....
Now, this would greatly impact the work of software developers. The idea...
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by: isladogs |
last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM).
In this session, we are pleased to welcome a new presenter, Adolph Dupré who will be discussing some powerful techniques for using class modules.
He will explain when you may want to use classes instead of User Defined Types (UDT). For example, to manage the data in unbound forms.
Adolph will...
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by: adsilva |
last post by:
A Windows Forms form does not have the event Unload, like VB6. What one acts like?
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by: 6302768590 |
last post by:
Hai team
i want code for transfer the data from one system to another through IP address by using C# our system has to for every 5mins then we have to update the data what the data is updated we have to send another system
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by: bsmnconsultancy |
last post by:
In today's digital era, a well-designed website is crucial for businesses looking to succeed. Whether you're a small business owner or a large corporation in Toronto, having a strong online presence can significantly impact your brand's success. BSMN Consultancy, a leader in Website Development in Toronto offers valuable insights into creating effective websites that not only look great but also perform exceptionally well. In this comprehensive...
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