Somewhat new to SQL and processing loops. I have a non-keyed file and I want to get the next record in sequence .. grab data needed and update it as used. This class is called from a GUI interface so I only need to grab the NEXT record each time..
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I have an Access table which has an auto-number primary key. When I add a new record to it I want to be able to get the value of this field.
The relevant code I have is:
dsNewRow.Item("FullName") = NewStudentFields(0)
dsNewRow.Item("FirstName") = NewStudentFields(1)
dsNewRow.Item("LastName") = NewStudentFields(2)
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I want to be able to access the value of the primary key immediately after the Update (if that's possible without having to search the dataset for the new record - cumbersome!) or, even better, just before the Update, if that's possible.
I am using ExecuteReader commands to read records in large external databases. Part of my program logic requires that a condition of the database be examined without reading another record - for instance, I want to know if the database has reached the end without reading an additional record.
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Is there a direct way of generating a class from a record in the database?I use a program to edit records and would like to use a class that has the record fields as member for saving the last values entered while adding new records and the initial values of the fields for editing so that if i press ESC the control while editing the value returns to the original.I tried to use dim r as datarow but i get the error that there is no object
and if i declare dim r as new datarow i get the error that new is not implemented.Do I have to write the class definition explicitly?
I'm having trouble reading a simple xml file with the XmlDocument class. Here is my xml file:
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I want the title attribute of the node but it gives me a message box instead saying: "System.Xml.XmlAttribute" How can I convert that or in some other way get the title attribute of the books? Another problem I will be running into is storing the books and readers in a 2D array dynamic array. How can I run through the <readers> nodes to store them in an array within the nodeTitle For Each loop?
I have a collection of objects (classes I created), and each one ties to a record in a database. I want an easy way to update the information, so I thought about declaring a record in the class, that would tie to the record on the database. However, I'm having a problem updating it now.
1) Can I declare a global variable for the data context, and leave it open the entire time the program is running? This would solve my problem, but I don't know if I can do that.
2) If not, besides coming up with a complicated class to do this, is there an easier way? Here is an example of what I am trying to do:
VB.NET
Public C as Record
Public Sub GetValue()
Dim SQL As New DBDataContext
Dim X = From T in SQL.Records Select T
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I hav a web service which pull records from a database and I am hosting these services in IIS which works fine but I am trying to retrieve the record and display the record in a listbox displaying the time field as the text for that record.I have created the following function
public sub get_data()
dim dt as new data.dataTable
dim service as ws webservice.webservice
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I'm trying to take a resultset, store in a class then retrieve the complete record for a given value. For example, the recordset has AnalystID (Unique), LastName, FirstName. I want to be able to pass the AnalystID and return the name. I need the ability to look up either last or firstname by analystID throughout the program. Here's what I have so far. I'm not sure I'm even headed in the right direction.
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I am able to query/read the "Application" event log using System.Management classes in VB.net 2005 (win xp)But I have problem reading the "Message" / "description" of my custom event log.I am getting a System.NullReferenceException{"Object reference not set to an instance of an object."} while reading the "Message" / "Description of the event log while it is reading the others properties.Also when I use System.Diagnostics.EventLog and read all the Events on by one I am able to read the message/description of my custom event log. Why is that the System.Management classes can't read the my custom event log messages while the System.Diagnostics.EventLog classes can read them.The reason I want to use System.Management classes is bcoz I can query my custom event log where as with System.Diagnostics.EventLog classes I have to read the whole event log.
View 2 RepliesI am able to query/read the event log using VB.NET 2005 (Win XP). But still I have a problem reading the "Message" / "description" of the event log.I am getting a System.NullReferenceException while reading the "Message" / "Description" of the event log.Also when I use System.Diagnostics.EventLog and read all the Event on by one I am able to read the message/description of the event. This is the code:
Public Sub ReadEvent()
Dim iCount As Int16
Dim PastFourHours As Date = Date.Now.AddHours(-4)[code]......
I am trying to check a record in database before inerting a new record here is my code but problem is when i enter a names first alphabet it imediatly populate massage. i want to check it after entering whole name
Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
Try
Dim cnString As String = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" &
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I need to write data to a file, preferably in binary format, but I am unaccustomed with the concept. Where's the easiest place to get the basics? I could come here with a specific need, but I'm at the point right now where I am more willing to work within the confines of keeping it simple.
Here's what I know:
1. how to open a new file
2. how to specify the record length
3. how to close the file
Some specific questions:
Does the record length have to be constant throughout the file?
Can I read the nth record without reading the whole file?
How do I force users to save the current record (if current record has changed) and not let user go to the next record unless the save button is pressed?
View 5 RepliesI am using Visual Basic 2010 Express. I am just learning LINQ, and so far loving it. I would like to use LINQ to query an ACCDB backend (built with Access 2007/2010). I am assuming that this is accomplished with LINQ to DataSet. I must use filtering criteria which are defined by the user at runtime, both in the selection of which fields are to be filtered, and in the values which are to be matched. How I intend to accomplish this (unless somebody has a better idea), is to build a "Criteria" class with members representing field, operator, value triplets (eg: fieldname="OrderCount" comparison=">" value="3"). I was then going to overload the equivalence operator so that comparisons between a "record" object and a "criteria" object would be conducted by a method of my choosing, and return true only if those field, operator, value triplets specified evaluated to true when provided a record object.My question is, what class of object is it that I must specify in my overload for a query such as:
HTML
From record In table
Where record = criteria
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I want to reading in a excel file and extract the sCodenumber sDescription ans the sStatus and store them in a array : StatusComposeArray(5200) As MyCompose. After this I need this array for comparing outside this class. But as can you see the array is defined inside the sub: ReadingIn_ExcelFilesCompose [Code]
View 2 RepliesWhile I've previously many years of relational databases and procedural languages, I'm stumbling with Visual Basic. In this problem, the simple situation is that I have two files, parent and child. The primary key of the parent file (Area file) is linked by a relation to one of the two fields that makes up the primary key in the child file (Project file) (unique key is formed from 'area' and 'project'). I have the default table adapters created on both files. I have created two maintenance forms showing one each of the two files in datagrid view format.I can create some records in the Parent (Area) file, but when I try to create a record in the child (Project) file, using one of the valid key values from the Area file, I get the 'ForeignKeyConstraint [relation name] requires the child key values [actual value] to exist in the parent table' which I'm absolutely definitely sure it does.
I haven't done any actual coding for those two maintenance forms, just dragged-and-dropped the files from the data sources screen onto separate forms so it creates the controls itself. But I can't work out, if it already knows the data does exist because I can load it back in to the Area maintence form, why it can't check itself to find out the record does exist. Why does it think the record from the parent record doesn't exist? It does exactly the same thing, whether or not the database is in access or SQL Server Express. I have all the latest updates.
I have two tables Products and Categories with a many to many relationship. I am trying to copy the categories linked to one product (OriginalProduct) to another product (newProduct). The problem is when I execute the SaveChanges() method, I not only get the records in my linking table, but it also creates another copy of the categories in the categories table. I've tried this in many ways but here are the last couple that I've attempted:
' Copy Product/Categories
For Each oneProdCategory In OriginalProduct.Categories
Dim relatedCategory = _productContext.GetObjectByKey(New EntityKey ("ProductInfoEntities.Categories", "RecordId", oneProdCategory.RecordId))
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I have a problem with my program, and it's really bad because I need to burn it to disk within 12 hours and I can't get it to work: If I create a record, add information to it and click on Next Record, the ID, Status and Notes boxes content will change but the rest of the controls contents are carried over to the next record and I don't know why or how. It was working perfectly but now it stopped and I never done anything.
View 8 RepliesI am handling many of the BindingNavigator tasks (MoveFirst, MoveNext, etc.)in code to ensure that I always ask the User to save his changes.
The one area I am have a problem is PositionItem. I would like to sense that the User has changed the Record Number in the BindingNavigatorPositionItem, handle my record Update, and move to the Record Number the User entered I have looked all over and have not found any way to do this.
I have created a project that has an add a new record, edit record and a search form, that has multiple text, combo boxes and is working great.Last nite I have added a checkbox under my add new record form and i am saving the checkbox value to my database, so far so good. I would like to be able to search any record that is mark with a checkbox to show up in my search screen when I do a search: [code] The problem that i am having is that now that I have added the code to my project to search for the checkbox field in the search screen and if I leave everything blank and click on the the search button I get no record found. I expected to see all that data, since I have nothing selected. Now if I click my checkbox, as soon as I click on my search button I see that two records that I have added for my test.
View 1 RepliesMy database : table1
ID FIRSTNAME AGE
1 Sumit 22
2 Sanjeev 23
i have gridview 1 and textbox1 and button1 i want when pages load the gridview displays the all records from table1 and also ...i i wanna search record for firstname by typing sumit in textbox1 and click on button1 then in gridview the record of sumit will be shown ..by default gridview display alll records from table1 How to do this My Selct Query is below : but it doesnot display all record ...but it can display record if you search for a particular record .
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I have records in a database. Each record has a Picture path in it eg. "C:\Pics\Image1.jpg". I would like to display a record from my database and also the picture for that record, in a .rdlc report in vb .net 2008. i have succeded in displaying the record but just can't get the picture to show. I am using an Imagebox in the report.
View 2 RepliesI use This Code To Save Data in Table First I delete record Then Insert record
View 4 RepliesI am trying to write a system that will send an email to my Client and when my client reply I need to read the Email and push it back to proper Record for the Client.We are using Exchange and outlook, For Sending email I am using smtp with custom coding Which automatically record an email content to the Client File howerver how to read the reply as it is coming into outlook of user machine and push it back to the Proper Client record.
View 3 RepliesIm wondering how would i work with a text file. which would allow me to Read the next Record, Cut record out of the program.
View 15 RepliesI have a access database with these columns. USER_ID,COUNT,TIMES
Let say the current record is this:
USER_ID,COUNT,TIMES
STEVE20,24,1.5
Now I want to updated the current count record and times, but before updating I want the old record to be added to the new record. What should be my query?
I'm receiving the following error:"You cannot add or change a record because a related record is required in table 'FORN_NIB'."
I cannot understand this error fr the related record really existe on the FORN_NIB table. It is even picked up from there. Here's the code where the error occurs at the .Update instruction:
HTML With rst
.Open("DADOS_RECIBOS", conn, ADODB.CursorTypeEnum.adOpenDynamic, ADODB.LockTypeEnum.adLockOptimistic)
.AddNew()
.Fields("NUM_FORN").Value = Me.TextBox1.Text
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Basically, I am making a booking system. On one of the forms, you can: Add, Edit and Delete a record by using the selected index. I can do the Add and Edit part fine but some problems are occuring when I try to delete it. What I'm trying to do when deleting is, copy all the records except the selected one and then copy it back into the original file again.
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Visual Studio Pro 2010 Win 7 64 bit running bootstrapped to a MacBook Pro i5 (blasphemer!!!) works really well though!!New to vb.net, have used vb6 for several years and finding the transition interesting to say the least.I have an access database with a vb.net front end all auto bound by the connection and binding wizards (I know, I know...) Not too complicated, but a simple 2 table related db. On the form the parent table shows customer details with the child table related and displayed by datagrid. I have a field in the child table for images and I have figured out how to store and retrieve images to the db. I am using the datagrid.rowheadermouseclick event to reload the picturebox on the main form as I click down the child table datagrid. Now I need to be able to click the bindingnavigator, go to the next record and have the program reload the image for the next child record. The problem is I'm trying to use an event from either the datagrid or bindingnavigator to reload the picturebox in the child table after moving to the next record, but all of the events I am trying are firing before the next record is moved to and therefor the logic I'm using to retrieve the image from the db is not working.
Anyone with an idea on how to move to the next record and then run my logic to populate the picturebox? What events might I use that fire after the next record has been populated? I know this is probably not that hard, but I have been racking my brain all day now.
This code i had use for create a field in DB Access 2003:
SQL = "ALTER TABLE plano_contas ADD declperiodica06A char(40) WITH COMPRESSION NULL)"
Dim command1 As New OleDb.OleDbCommand(SQL, con1)
con1.Open()
command1.ExecuteNonQuery()
con1.Close()
like you see the code create a Text field with 40 lenght...Well the problem is:When i save a new record the record it's save in this mode: "100......... .........................." - the points means spaces and should be:"100"After try a lot of things i'm without more solutions in find why this happen!
