im making a class.vb which has a sql connection. The class.vb will be used by all forms/windows on the application. So whenever a form needs to access the database, it will call class.vb.
This is the code in class.vb:
Public Sub Openconn()
Dim myConnection As SqlConnection
Dim connstring As String = "Data Source=192.162;Initial Catalog=db1;User Id=sa;Password=1;"
[code]....
but it gives error: value of type sqlconnection cannot converted to array of Sqlconnection.I just want a method that's useful for opening the connection and that is also useful when asigning to a command object.
I'm designing a web service in ASP.NET and VS2008, and am using typed datasets for retrieving table data. These work well and establish their own connections through their associated TableAdapter objects. Edit: I'm using VB, BTW!I am now attempting to run a custom SQL string using a DataAdapter and a Command object, however I need to reference a Connection object in order for the Command to work. What is the best way to handle this?hould I:a) Create a global connection object using Global.asax, retrieving the connection string from web.config? (I've been trying that one already, with not much success)b) Create a class-level connection object using the InitialiseComponent method, also retrieving the ConnectionString from web.config?c) Retrieve a Connection from one of the TableAdapters that I've already created in my typed DataSets?d) Something else I haven't thought of yet?
Any ideas on how I handle the following error thrown in the SqlDataAdapter.Fill as a result of the BeginTrans in the callee?
System.InvalidOperationException = {"ExecuteReader requires the command to have a transaction when the connection assigned to the command is in a pending local transaction.The Transaction property of the command has not been initialized."}
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?
SQL connection - I planned to create one sql connection object inside my own singleton class (say connectionmanager with Reference counting for 'SQL connection object' which is a member of the class) and open/close the connection whenever needed. As I like to give high importance for performance. And my application is a desktop based application accessing a remote database server (SQL server 2008), and will use only one connection string, 50 concurrent desktop users may access db server. Please advice.
As like many articles say if the answer is "Connection pooling is taken care by ado.net" - Does that mean that scope of connection pool is entire life of Application instance? Or is it in the scope of SQLConnection object?
I am getting errors when I try to use this adodb.connection and command in my code. The error I am getting is saying that the connection and command are not defined. I read online that depending on your version of vb that you might use the "OLE" connection instead of ADODB.
I have some classes, BsfciFile and StudyFlashCard. Bsfci is the extension to which I save my set of flashcards in an INI format. I am currently working to transform my code from using Windows API calls to access the INI to using a IniFile class that I found on the internet. I would like the BsfciFile to have a Array of StudyFlashCard objects, but I would like the StudyFlashCard class to use the IniFile class object contained in the BsfciFile class. I can pass the IniFile from the BsfciFile class to the constructor for the StudyFlashCard class, but I want it to modify the same IniFile as the BsfciFile class has later on.
i was using a pocketpc phone and i want to have a program it with a database.i am not familiar w/ the database of vs 2k8 because it was using a dataset i i dnt know how to connect the database of that...
I am trying to create an list or an array of a class.Here is my "Ingredient" class that I am trying to create a list of:[code]In my "recipe" class, I am want to create a list (or array) and I am drawing a big blank on how to do it. Can anyone point me in the right direction?
dim myCollection as new Specialized.StringCollection dim myFoundThings as new ArrayList dim index as Integer dim newResultMemberName as String
[code]....
This is part of some code that will run without user interaction once it's spinning away, and I need to create a unique object from some items found in a StringCollection, naming the objects using information found in the strings stored in that StringCollection.
i've created bunch of classes. i have webservices which reference these classes and contains the classes as parameters and return objects.when i call the weservice, i have to convert the class to the webservice object else i can type conversion error.is there a generic way to convert between these types without having to assign the values by hand?
for example
public class person fname as string lname as string end class
[code]....
i would liek ot be able to call the web service and return the data type back and have a generic coversion instead of as above in stead of:
dim wsPerson as wsReference.Person = ws.getperson()
I have a class in which some of the fields are also classes.
I can put values in the "normal" properties, but in the others when o try to assign values it gives the: "Object reference not set to an instance of an object"
But the code compiles fine.
dados_Defenicao = New ServiceReference1.draftClaimEntryDefinition dados_Defenicao.arCode = "123" dados_Defenicao.claimMarket.warrantyType = "w" - Here it gives the error
If we are within the derived class then ofcource we can use MyBase keyword to access base class's object reference . That's fine , how can we take that base class's object reference outside that derived class's definition.My following code will explain what i want . Actually that is giving error right now, but it is explaining my requirement .
Public Class Base Public x As String End Class
[code]....
Actually there is error in ReadOnly Property BaseReference's Getter . Error is "Error 1 'MyBase' must be followed by '.' and an identifier. " how can i get base class object reference in Main method ?
If my namespace is Company.Application.EDI.Acknowledgement and if I stick with theprogramming practice of one class per file then should my class be saved asacknowledgement.vb? Are there any gotchas that will come up?
I have a Parent Class Called Fuselage that containsfour child classes called Forebody, CenterBody, AftBody, and CrossSection. CrossSection classcontains objects common to Forebody, CenterBody, and Aftbody (example: width). How do I access thewidth property in CrossSection from within the classForebody?
Public Class Fuselage Dim Forebody As ClsSection Dim Centerbody As ClsSection
i connect the Datagridview by using command connection not coding. now i have "table3tableadabter", "table3bindingsource" and "database3dataset" below the form ? the search string " "Select * from tabel3 Where test2 like '" & Me.TextBox1.Text & "%';"" how i can do serch and the result will be shown in datagridview.
I am developing an IT Asset Tracking application using VB 2005 and SQL Server 2005 Express edition. Will I need to create classes to represent objects such as Computers, Printers, Scanners/Faxes, Contracts, Purchase Orders etc or are there any other approaches.For example, if I am correct, I will have a class called Computer and its properties will include Make,Model,CPU,Hard Disk,Memory etc. Is this the right approach.
Computers can be split up into Desktop PC's, Servers and Notebooks. Would I have to create separate classes for these as well or would they be ok under the Computer class.Once I create an object from the class, how can I use the object to interact with the SQL db.I am a beginner to VB.NET 2005 therefore I am slowly getting to grips with OOP.
I have been working on this all day and still haven't had any luck at getting it to work. I am using the SqlDataReader Object to retrieve data. I am using the code below to send a value to the stored procedure.The problem is that the value is sent enclosed in quotes so I dont get any data back. I have tried using .text.replace("""","")
I created a connection class that should return a datatables/datareaders etc to my webpages. I am worried that the connections won't be closed properly by using this class. Here is the class: [code]I am worried that once I go into production the connections won't be close properly and my site will fail. I am new to .net, is there anything wrong with the principal behind this class?
I have 2 panels and what to run a command when they are a minimum of 30 pixels away from each other. Ive tried pnl1.intersectwith(pnl.bounds - 30) but doesnt work out
I'm helping a colleague develop a "catch all" type error handler for some controls his application. What he wants to do is pass the object that has the error, and the type of that object, such a TextBox or ComboBox, and then call the DirectCast method within his handler to properly address the Text attribute within it. In general, the method is looking like this:
Protected Sub SpecialErrorHandler(ByVal TargetControl As Object, ByVal ControlType As String) MessageBox.Show("Bad Juice: " & DirectCast(TargetControl, ControlType(ObjType)).Text) End Sub
So far any attempts to do a type conversion within the DirectCast method (since it is expecting an object in the general signature) or to even pass in the a Type object properly set is not working.
Any ideas here, or is this one of those "Casting doesn't work that way." type scenarios?
