How to Connect PostgreSQL with VB.NET Application

Connecting PostgreSQL with a VB.NET application involves establishing a data connection using either ODBC or Npgsql. Here's a comprehensive guide:

1. Connecting with ODBC:

1. Install ODBC Driver: Download the PostgreSQL ODBC driver from the official website (http://www.postgresql.org/ftp/odbc/versions/msi/). Install the 32-bit driver.
2. Create a Connection String: Define a connection string using the following format:

   
           Dim MyCon As New Odbc.OdbcConnection
           MyCon.ConnectionString = "Driver={PostgreSQL ANSI};database=database_name;server=127.0.0.1;port=5432;uid=postgres;sslmode=disable;readonly=0;protocol=7.4;User ID=postgres;password=password;"
       

3. Open the Connection: Open the connection to the PostgreSQL database using the following code:

   
           MyCon.Open()
           If mCon.State = ConnectionState.Open Then
               MsgBox("Connected To PostGres", MsgBoxStyle.MsgBoxSetForeground)
           End If
       

2. Using Npgsql Library:

1. Install Npgsql: Install the Npgsql library using the NuGet Package Manager in Visual Studio. Search for "Npgsql" and install the latest stable version.
2. Create a Connection String: Define a connection string using the following format:

   
           Public cn As NpgsqlConnection
   
           Dim cs As String 'ConnectionString
   
           cs = "Server=127.0.0.1:5434;Database=extraits;Userid=postgres;Password='********'"
       

3. Open the Connection: Open the connection to the PostgreSQL database using the following code:

   
           cn = New NpgsqlConnection(cs)
           Try
               cn.Open()
           Catch ex As Exception
               MsgBox(ex.Message)
           End Try
       

4. Execute Queries: Execute SQL queries using NpgsqlCommand and NpgsqlDataReader objects. For example:

   
           Dim sSQL = "SELECT version()"
           Dim cmd As New NpgsqlCommand(sSQL, cn)
           Dim dr As NpgsqlDataReader
           dr = cmd.ExecuteReader()
           dr.Read()
           Dim sVersion As String = dr.Item(0)
           Console.WriteLine("PostgreSQL VERSION: " & sVersion)
           dr.Close()
       

Both methods allow you to connect to a PostgreSQL database from a VB.NET application. Choose the approach that best suits your project's requirements and preferences.