VB.Net/Data Structure/Connection
Check the state of the connection and report appropriately
<source lang="vbnet"> Imports System Imports System.Data Imports System.Data.OleDb Imports System.Data.SqlClient Imports System.Collections Imports System.Windows.Forms Imports System.Resources Public Class MainClass
Shared Sub Main() "Declare variables and objects Dim strConnectionString As String = _ "Provider=Microsoft.Jet.OLEDB.4.0;" & _ "Data Source=Employee.mdb;" Dim objConnection As New OleDbConnection(strConnectionString) Dim strSQL As String = _ "SELECT FirstName, LastName FROM Employee" Dim objCommand As New OleDbCommand(strSQL, objConnection) Dim objDataAdapter As New OleDbDataAdapter(objCommand) Dim objDataTable As New Data.DataTable("Employee") Dim objDataRow As DataRow Try "Open the database connection objConnection.Open() "Check the state of the connection and report appropriately If objConnection.State = ConnectionState.Open Then Console.WriteLine( "Database connection is open") Else Console.WriteLine("Database connection failed") End If Catch OleDbExceptionErr As OleDbException "Write the exception Console.WriteLine(OleDbExceptionErr.Message) Catch InvalidOperationExceptionErr As InvalidOperationException "Write the exception Console.WriteLine(InvalidOperationExceptionErr.Message) End Try "Close the database connection objConnection.Close() "Clean up objDataRow = Nothing objDataTable.Dispose() objDataTable = Nothing objDataAdapter.Dispose() objDataAdapter = Nothing objCommand.Dispose() objCommand = Nothing objConnection.Dispose() objConnection = Nothing End Sub
End Class
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<A href="http://www.vbex.ru/Code/VBDownload/Employee.zip">Employee.zip( 7 k)</a>
Database Connection Properties: version, data source, WorkstationId, database and etc
<source lang="vbnet"> Imports System Imports System.Data Imports System.Data.SqlClient public class MainClass
Shared Sub Main() Dim connString As String = "server=(local)\SQLEXPRESS; " & _ "integrated security=sspi;" Dim conn As New SqlConnection(connString) Try conn.Open() Console.WriteLine("Connection Opened") Console.WriteLine("Connection Properties") Console.WriteLine("- ConnectionString : {0}",conn.ConnectionString) Console.WriteLine("- Database : {0}",conn.Database) Console.WriteLine("- DataSource : {0}", conn.DataSource) Console.WriteLine("- ServerVersion : {0}", conn.ServerVersion) Console.WriteLine("- State : {0}", conn.State) Console.WriteLine("- WorkstationId : {0}", conn.WorkstationId) Catch ex As SqlException Console.WriteLine("Error: " & ex.ToString()) Finally conn.Close() Console.WriteLine("Connection Closed") End Try End Sub
End Class
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