I have a need to populate a data object containing 30+ properties from a database table. I could create a simple class containing a public variable for each of the required properties, but I don't want to.
Is the following code a bad idea:
<Serializable()>
Public Class DtoEmployee
Public EmployeeId As String
[Code].....
I have made DataGridView in the designers and connected an Access database to the datagridvies and the Column headers appear as they should and when I check in preview mode all the fields are correctly populated. However, the DataGrid is not populated in normal mode at all. I have been trying to run the project but nothing is happening. What can I do to populate the field.
View 12 RepliesI have a table in a HTML report that I want to populate with data from a Database. The headings are Customer ID, Amount to Pay, Amount Paid, and Total Owing.I am running the SQL Query:
SELECT CustomerID, SUM(AmountToPay)" & vbCrLf & "FROM Orders" & vbCrLf & "WHERE CustomerID = 20202" & vbCrLf & "GROUP BY CustomerID" & vbCrLf & "UNION" & vbCrLf & "SELECT CustID, SUM(AmountPayed)" & vbCrLf & "FROM Payment" & vbCrLf & "WHERE CustID = 20202" & vbCrLf &
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I am having a remote server it has INVENTORY DATABSE , and also iam having same databse in my local system. I want to populate by local database table with my Remote database table through Vb.net code by click a button. How to do this .
View 1 RepliesThe control comes up blank??Imports System.Data Imports System.Data.OleDb Public Class Form1
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Here is the code that I already have:
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I'm looking to populate an object then display the data to labels.[code]...
View 2 RepliesI am using vb.net to code and sqlserver 2008 as backend.I have a checkboxlist that needs to be filled up with data from the database.The data in the field is comma delimited (Blue, Red, Orange...)How do i populate my checkbox with this data from the DB?
View 1 RepliesI want to be able to populating a data from my oracle database into vb.net
View 1 Repliesi have several classes / objects from it in a program that hold data like clsAddress with properties id, city, zipcode, name, and clsMyData that contain id, datafield1, datafield2, datafield3 and many more (just examples) I want to have methods in the objects to load the object from and save the object into a database, like me.loadFromDb and me.SaveToDb Of course i can do creating db tables like tAdress, tMyData, ... and in the methods do select / insert statements like "insert into adresses (city, zipcode, name) values(me.city, me.zipcode, me.name) etc. BUT - what i dont like is a) i need to build this loadfromDB / saveToDB Methods for every class separately and b) whenever i alter a class, i must alter the DB structure and the methods.
View 6 RepliesI have a class that represents the table of a db-row. Its properties are the columns of the table. I add a new row to the table with the following code:
Public Sub AddRow(oTestRow As TestRow)
Dim sql As String
With oTestRow
[Code]....
That is just an example, but my classes have around 30-40 properties and this brings a very large and complex sql string. Creating, editing or maintaining these sql strings for many classes could generate errors. I am wondering if any compact way or method exists in order to add the whole object's istance (the properties of course) to the table "TestTable" without writing such a large sql string. I created the TestRow in the way that its properties are exactly the columns of the table "TestTable" (with the same name). But I did not found in the ADO.NET anything that could be used.
I am not sure how to phrase my question properly but I want to achieve something like this.
I have a class named Products public class Products
private ID as Integer
private Name as String
Public Property ProductID()
Get
Return ID
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When I do the same, I am getting an error "Object Reference Not Set to an Instance of an Object.
I want to populate a text box from a stored table I have this for the data
With DropDownList1
.DataSource = ds.Tables("property")
.DisplayMember = "propRef"
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Let's say I have an employee class with ID, Forename, Surname, Initials and Email Address properties.
At present, you can construct an Employee object by passing a data row which, typically will include all these fields. However, sometimes I only want the ID, Forename and Surname but still want to populate an object.
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However obviously if certain fields are not present in the data row, I will have an error. Is there a quick way of populating the object based on the fields that are present within the data row without a) having to have separate subs for each circumstance and b) without having to try / catch (or something similar) around each property? I know other languages have options like this - where if there is no value, it will be another value (i.e. a default).
I want to create a class (I think) that has properties that correspond to column names in a database table, such that they come up in Intellisense when I type the dot after the class name. Is this possible to do?
View 5 RepliesWe are creating a VB program for school to collect data on student attendance and populate it to a table. I have all of the 'GET' statements but am having trouble creating the 'Insert' procedure. This is what I have so far. The form being used to fill the table has 4 items being recorded. 'Present' radio button marked as present, tardy or absent; StudentId, PeriodId and date. Not sure if we are on the right track. The target table is tmAttendance. There are approximately 25 rows of data on the input form.
View 3 Replieshow to implement UI, BL and DAL in a project the way that I see it as a requirement for some projects. The way I am able to do a project now is from a form create an object of a class in which there are properties and functions that do database selects, updates and deletes. Looks to me that doing a project like that is separating the UI from the DAL. In an update button click event I may call Obj. Delete (txtCustID.txt) for example. I don't understand the part of further breaking it down to include a Business layer; in which a vb solution is made up of three solutions.What goes in the BL?Does the BL call the DAL?
View 2 RepliesIm doing my first project with WinForms, and Im trying to get the DataBinding working. Theres no database in my project, but I'd like to bind some of the TextBoxes to objects' properties. In the other section of this forum (here) I found this line of C# code which does it: textBox2.DataBindings.Add(new Binding("Text", this.myPerson, "LastName"));
my question is can data binding to object properties be set up during design time (without writing code)? If so, how? P.S. I know how I would set up this binding if in WPF, but I'm forced to use WinForms.
I am somewhat new to object oriented programming and am attempting to flatten a Linq object hierarchy by using a shim class.how to initalize a derived class with property values from a base class?I have two objects, a base object with about 100 properties, and a derived object which inherits from the base object and adds a few additional properties beyond those of the base object. My simple constructor creates the derived object, but I am looking for a way to initialize the derived object properties with values from the base object.Right now I am using reflection to iterate over the properties individually and I suspect there may be a better way. The following example shows my shim class constructor for the derived class, and two properties:
newProperty1 - a new string property of the derived class
flattenedProperty2 - a new string property of the derived class, copied from a 2nd-level object of the base class
Code example:
Public Class derivedObj
Inherits baseObj
Private _newProperty1 As String[code].......
Is this the correct constructor approach to flatten the object hierarchy using a shim class? My second question relates to initialization of properties in the derived class. The constructor above creates the derived object, but what is the best way to initialize the derived object properties with values from the base object? The following code uses reflection to iterate over the properties individually, but I suspect there may be a better way.
Code example:
' property names are in the string array fieldNames
'baseObjQuery is an ienumerable of baseObj
'derivedObjList is a list of derivedObj[code].....
Is there a simple way to initialize values for the properties in the derived object based upon the values of the common properties in the base object?
Im new to vb.net and would like to know the very basics on how a datagridview works? how does it populate data from the database? what process does vb follow to update this datagridview? I'm trying to get my head around the following terms and need some explaining how they work and how they are linked? if possible, is there a link to a diagram that explains this?
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can someone please give me basic steps on how to hard code a combo box to display a column from a database?
View 21 RepliesPopulating a listbox with data from a database
View 2 RepliesI was create Access database with Access 2003. I create VB project with Visual Studio 2005 Standard With connection wizzard I create coonect with this Access database, select all tablesI see this database inside Data sources and inside Server explorer Test connection is OK When I drag and drop table from Data sources, Wizzard don't create DataGridView, DataSourceBinding etc .. and I see popup window with mesage: Object reference not set to an instance of an object and then "game over"
View 2 Repliesi want to populate a listbox from a sql database and foll is the code i encountered error with:
Dim con As SqlConnection
Dim cmd As SqlCommand
Dim lrd As SqlDataReader
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I need to populate data (Patient ID and name) from a MS Access Database table (PetientInfo) into a listbox depending on date (Datetimepicker). The listbox item will change upon date changed.
When I select a item from listbox the details of the patient will show to the textboxes.
I want to pull data from database and populate an array. Field one: A short name to call the second. Field tow: A connection string to a database.
EG: Cstr=Connstr("OrDB")
The known name of OrDB would result in a string assigned to the variable Cstr that could be a connection string to an oracle database.
I have inherited some code from an external contractor that I have to modify. Firstly, he uses a strongly typed dataset to retrieve some data from an SQL database and then uses that data to populate a listbox. I have decided to use a dropdown list (as the user can only ever select one value at a time).This is the code that populates the DropDownList
Private Sub FillUserComputer(ByVal userId As String)
Try
TraceDebug("Begin FillUserComputer"[code]....
This works well for the first two entries in the DropDownList. However, whenever I select one of the other options and click the Send Request button it "jumps back" to the 2nd entry in the list and sends that data instead, completely ignoring the option I selected.I think I have narrowed down the problem to the fact that the DataValue for the second entry in the list is a Null value.
I am trying to convert some old VB6 code into VB.NET. The old code used DAO and now I am trying to replicate it in ADO.NET/OleDB. I have made some advances (I think...) but now I can't figure out how to add the DataTable object into the database.[code]So instead of the TableDef, I am taking the data from the same sheet and putting it in a DataTable object (dt). I hope this is correct so far. Now my question is how to replicate the m_db.TableDefs.Append td line from above.
View 1 RepliesI have an XmlDocument object in memory which I need to update a database table with. My SQL Express 2005 DB table is three columns: Name, Telephone, Location. Below is the structure of the XMLDocument. What is the recommended technique to accomplish this?
HTML
<MyDirectory>
<Prompt>Records 1 to 561 of 561</Prompt>
<DirectoryEntry>
<Name>John Doe</Name>
<Telephone>22334222</Telephone>
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I'm using VB.net 2005. I have working programs that I populate DataGridViews with something like the following:
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