Ping Method

In This Topic

Syntax
Remarks
Example
Requirements
See Also

Determines whether connection to PostgreSQL server is valid.

Syntax

Visual Basic
C#

public bool Ping()

'Declaration
 
Public Function Ping() As Boolean

Return Value

true, if the connection is valid; otherwise, false.

Remarks

If the application has an open connection for a long time, it is recommended to check a connection for validation before using it. Call of Devart.Data.PostgreSqll.PgSqlConnection.Ping method has single round trip on PostgreSQL server.

It is not a good idea to keep a connection open for long time. Connection pool automatically pings all connections within, thus closing old connections and opening new ones is encouraged.

Example

This code sample shows how to check for server availability before issuing a query.

csharp

public void ExecuteSafely(MySqlConnection myConnection)
{
  MySqlCommand myCommand = new MySqlCommand("INSERT INTO Test.Dept(DeptNo, DName) Values('50', 'DEVELOPMENT')");
  myCommand.Connection = myConnection;
  try
  {
    if (myConnection.Ping())
    {
      myCommand.ExecuteNonQuery();
      Console.WriteLine("Successfully executed");
    }
    else
    {
      myConnection.Close();
      Console.WriteLine("Unable to ping the server");
    }
  }
  catch
  {
    myConnection.Close();
    Console.WriteLine("Error during query execution");
  }
}

Visual Basic

Public Sub ExecuteSafely(ByVal myConnection As MySqlConnection)
  Dim myCommand As New MySqlCommand("INSERT INTO Test.Dept(DeptNo, DName) Values('50', 'DEVELOPMENT')")
  myCommand.Connection = myConnection
  Try
    If (myConnection.Ping()) Then
      myCommand.ExecuteNonQuery()
      Console.WriteLine("Successfully executed")
    Else
      myConnection.Close()
      Console.WriteLine("Unable to ping the server")
    End If
  Catch
    myConnection.Close()
    Console.WriteLine("Error during query")
  End Try
End Sub

Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

PgSqlConnection Class
PgSqlConnection Members

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