Create a database connection class in vb.net

vb.net , sql server , access Colombo, Sri Lanka
  • 7 years ago

    Hi all, I am new to vb.net. I was created an inventory control system. It contain may forms with database connection. I want to know, How to create one class file to connect all forms with database, If any one know please help me. Thank You.

  • 7 years ago

    '====================================== 'Save this as a seperate vb file.when u need to access create an instance and access the related method '======================================= Imports System.Collections.Generic Imports System.Text Imports System.Data.SqlClient Imports System.Configuration Imports System.Data Imports System.Windows.Forms

    Namespace CSharpPractise Public Class DAL Private connectionStat As SqlConnection

    	Public Sub New()
    		connectionStat = New SqlConnection()
    	End Sub
    

    '===================================== 'Open the connection Public Sub SQLConnection() Dim connectionToSQL As New SQLConnectionStirng() connectionStat.ConnectionString = connectionToSQL.getCon() If connectionStat.State = ConnectionState.Closed Then connectionStat.Open() End If

    	End Sub
    

    '=========================================

    '================Close the connection====== Public Sub SQLDisCon() If connectionStat.State = ConnectionState.Open Then 'connectionStat.Dispose();

    			connectionStat.Close()
    		End If
    
    	End Sub
    

    '=================Returns a Data Table============ Public Function returnDataTable(strCmd As String) As DataTable

    		SQLConnection()
    		Dim da As New SqlDataAdapter(strCmd, connectionStat)
    		Dim dt As New System.Data.DataTable()
    		da.Fill(dt)
    		SQLDisCon()
    		Return dt
    
    	End Function
    

    '===================================== '=============Execute SQL Command====== Public Function executeSQL(cmdtext As String) As Integer Try SQLConnection() Dim cmd As New SqlCommand(cmdtext, connectionStat) Return cmd.ExecuteNonQuery()

    			SQLDisCon()
    
    		Catch e As Exception
    			Throw e
    		End Try
    	End Function
    

    '===================================== '===========Returns a Dataset============= Public Function returnDataset(query As String) As DataSet SQLConnection() Dim ds As New DataSet() Dim da As New SqlDataAdapter(query, connectionStat) da.Fill(ds) Return ds 'SQLDisConnection(); SQLDisCon() End Function

    End Class
    

    End Namespace

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