PgSqlCommand Class

In This Topic

Represents a SQL statement or stored procedure to execute against PostgreSQL.

Syntax

Visual Basic
C#

'Declaration
 
Public Class PgSqlCommand 
   Inherits Devart.Common.DbCommandBase
   Implements System.ComponentModel.IComponent, System.Data.IDbCommand, System.ICloneable, System.IDisposable

public class PgSqlCommand : Devart.Common.DbCommandBase, System.ComponentModel.IComponent, System.Data.IDbCommand, System.ICloneable, System.IDisposable

Remarks

The PgSqlCommand class provides the following methods for executing commands against the PostgreSQL database:

Item	Description
ExecuteReader	Executes commands that return rows.
ExecutePageReader	Returns a specific subset of rows when paging through the results of a query.
ExecuteNonQuery	Executes SQL commands such as INSERT, DELETE, UPDATE.
ExecuteScalar	Retrieves a single value (for example, an aggregate value) from a data source.

If execution of the command results in a fatal PgSqlException, the PgSqlConnection may close. However, the user can reopen the connection and continue.

This class supports cross-form data binding with the InterForm Technology.

Example

The following example uses the ExecuteReader method of PgSqlCommand, along with PgSqlDataReader and PgSqlConnection, to select rows from a table.

csharp

public void ReadMyData(string myConnString)
{
  string mySelectQuery = "SELECT DeptNo, DName FROM Test.Dept";
  PgSqlConnection pgConnection = new PgSqlConnection(myConnString);
  PgSqlCommand pgCommand = new PgSqlCommand(mySelectQuery,pgConnection);
  pgConnection.Open();
  PgSqlDataReader pgReader = pgCommand.ExecuteReader();
  try
  {
    while (pgReader.Read())
    {
      Console.WriteLine(pgReader.GetInt32(0).ToString() + ", " + pgReader.GetString(1));
    }
  }
  finally
  {
  // always call Close when done reading.
  pgReader.Close();
  // always call Close when done reading.
  pgConnection.Close();
  }
}

Visual Basic

Public Sub ReadMyData(myConnString As String)
  Dim mySelectQuery As String = "SELECT DeptNo, DName FROM Test.Dept"
  Dim pgConnection As New PgSqlConnection(myConnString)
  Dim pgCommand As New PgSqlCommand(mySelectQuery, pgConnection)
  pgConnection.Open()
  Dim pgReader As PgSqlDataReader = pgCommand.ExecuteReader()
  Try
    While pgReader.Read()
      Console.WriteLine(pgReader.GetInt32(0).ToString() + ", " _
        + pgReader.GetString(1))
    End While
  Finally
      ' always call Close when done reading.
      pgReader.Close()
      ' always call Close when done with connection.
      pgConnection.Close()
  End Try
End Sub

Inheritance Hierarchy

System.Object
   System.MarshalByRefObject
      System.ComponentModel.Component
         System.Data.Common.DbCommand
            Devart.Common.DbCommandBase
               Devart.Data.PostgreSql.PgSqlCommand

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

PgSqlCommand Members
Devart.Data.PostgreSql Namespace
PgSqlDataReader Class
PgSqlConnection Class

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