OleDbConnection class in VB.net

By: Steven Holzner Emailed: 1757 times Printed: 2448 times    

Latest comments
By: rohit kumar - how this program is work
By: Kirti - Hi..thx for the hadoop in
By: Spijker - I have altered the code a
By: ali mohammed - why we use the java in ne
By: ali mohammed - why we use the java in ne
By: mizhelle - when I exported the data
By: raul - no output as well, i'm ge
By: Rajesh - thanx very much...
By: Suindu De - Suppose we are executing

An OleDbConnection object supports a connection to an OLE DB data provider. In practice, you usually use OLE DB connections with all data providers except Microsoft's SQL Server. Note that, depending on the OLE DB data provider, not all properties of an OleDbConnection object may be supported.

A central property of connection objects is the ConnectionString property, which holds a string full of attribute/value pairs that contain data needed to log on to a data provider and choose a specific database. These attribute/value pairs are specific to the data provider you're using, and make up a list of items separated by semicolons. You can either assign a connection string to the connection's ConnectionString property, or you can pass the connection string to the connection object's constructor, like this:

Dim ConnectionString As String = "Provider=SQLOLEDB.1;Integrated " & _
Security=SSPI;Persist Security Info=False;Initial " & _
"Catalog=pubs;Packet Size=4096;Workstation ID=STEVE;" & _
"Use Encryption for Data=False"

Dim Connection1 As OleDbConnection = New OleDbConnection(ConnectionString)

If you have no idea what a connection string should look like for a specific data provider and database, use the visual tools built into Visual Basic to construct a few sample strings to that data provider, which you can either use directly in code or modify as you need. To do that, create a connection to the source you want to use, then drag a data adapter to a project's main form, which creates both data connection and data adapter objects. Then take a look at the connection object's ConnectionString property in the Properties window.

Tip The most common attribute/value pairs used in OLE DB connection strings are also supported with properties of connection objects, such as DataSource, Database, UserId, and Password, which means that when you work with a connection object, you can either set the ConnectionString property as a string, or you can set various connection properties one-by-one and let Visual Basic create the connection string for you (unless your OLE DB provider requires data not supported by the connection object's properties).

After you've created a connection object, you can open it with the Open method, and assign it to the Connection property of a command object. (To specify the SQL you want to use, you can pass that SQL to the command object's constructor.) Then you can use the command object with a data adapter. For example, you might assign the command object to the SelectCommand property of a data adapter, and you can use the data adapter's Fill method to execute that command and fill a dataset. When done with the connection, use its Close method to close it. (The connection won't be closed otherwise, even if the connection object goes out of scope.)

Tip If your application uses a number of connections, you should use connection pooling to improve performance. (Connection pooling lets you keep a cache of connections without having to create new ones all the time.) When you use the OLE DB .NET data provider, connection pooling is enabled automatically.


VB.net Home | All VB.net Tutorials | Latest VB.net Tutorials

Sponsored Links

If this tutorial doesn't answer your question, or you have a specific question, just ask an expert here. Post your question to get a direct answer.



Bookmark and Share

Comments(0)


Be the first one to add a comment

Your name (required):


Your email(required, will not be shown to the public):


Your sites URL (optional):


Your comments:



More Tutorials by Steven Holzner
Changes in Controls from VB6 to VB.net
Throwing a Custom Exception in VB.net
Throwing an Exception in VB.net
Using Finally in VB.net
Using Multiple Catch Statements in VB.net
Exception Filtering in the Catch Block in VB.net
Raising an Exception Intentionally in VB.net
Getting an Exception's Number and Description in VB.net
Using On Error GoTo 0 in VB.net
Using Resume Next and Resume Line in VB.net
Understanding Scope in VB.net
Properties in VB.net
Procedure Delegates in VB.net
Preserving a Variable's Values between Procedure Calls in VB.net
Specifying Optional Arguments with default values in Procedures in VB.net

More Tutorials in VB.net
Scope in VB.net
Unstructured Exception Handling in VB.net
Structured Exception Handling in VB.net
Creating Sub Procedures in VB.net
Creating Functions in VB.net
Passing a Variable Number of Arguments to Procedures in VB.net
Specifying Optional Arguments with default values in Procedures in VB.net
Preserving a Variable's Values between Procedure Calls in VB.net
Procedure Delegates in VB.net
Properties in VB.net
Understanding Scope in VB.net
Using Resume Next and Resume Line in VB.net
Using On Error GoTo 0 in VB.net
Getting an Exception's Number and Description in VB.net
Raising an Exception Intentionally in VB.net

More Latest News
Most Viewed Articles (in VB.net )
How to export from DataGridView to excel using VB.net
Your first VB.NET Crystal Reports - A step by step guide
How to export from database to excel using VB.net
Insert cell data in an Excel file using OLEDB in VB.net
The Option and Imports Statements in VB .NET
Handling Dates and Times in VB.net
Sub Procedures and Functions in VB.net
A tutorial on Chat Server and Chat Client in VB.net
To read the entire worksheet in an Excel workbook through VB.net Code
What's New in VB .NET? A comparison of VB vs VB.net
Arrays and Dynamic Arrays in VB.net
How To Connect To A MySql Database in VB.net
How to Open and Edit Cells in an Excel 2007 file in VB.NET
Using Resume Next and Resume Line in VB.net
For Loop in VB.net
Most Emailed Articles (in VB.net)
How to export from DataGridView to excel using VB.net
How to send email using VB.NET code
Data types in VB.net
Arrays and Dynamic Arrays in VB.net
If…Else Statements in VB.net
ArrayList data structure in VB.net
Name Value Collecion in VB.net
Implicit & explicit type Conversion in VB.net
String equals, Copy to & Copy to in VB.net
File stream operations in VB.net
Vb.net binary reader and writer
Insert cell data in an Excel file using OLEDB in VB.net
Update cell data in an Excel file using OLEDB in VB.net
How to find IP Address of Host using .net code
Specifying Optional Arguments with default values in Procedures in VB.net