dotConnect for PostgreSQL Documentation
Devart.Data.PostgreSql Namespace / PgSqlParameter Class / Direction Property
Example

Direction Property (PgSqlParameter)
Gets or sets a value indicating whether the parameter is input-only, output-only, or bidirectional parameter.
Syntax
'Declaration
 
Public Overrides Property Direction As ParameterDirection
 

Property Value

One of the System.Data.ParameterDirection values. The default value is Input.
Remarks

Set Direction to System.Data.ParameterDirection.ReturnValue to obtain query result as parameter.

If the System.Data.ParameterDirection is System.Data.ParameterDirection.Output or System.Data.ParameterDirection.InputOutput, an exception is thrown.

Please refer to article Using Parameters for more information about parameters in dotConnect for PostgreSQL.

Example
This sample demonstrates how to retrieve the return value of a stored procedure with PgSqlParameter
using System;
using System.Data;
using Devart.Data.PostgreSql;

namespace ConsoleApplication4 {
  
  class Class1 {

    [STAThread]
    static void Main(string[] args) {

      PgSqlConnection connection = new PgSqlConnection("host=server;database=testdb;user=postgres;");
      PgSqlCommand command = connection.CreateCommand();
      PgSqlParameter pDeptNo, pDeptName, pDeptLoc;

      command.CommandText = "getdept";
      command.CommandType = CommandType.StoredProcedure;

      pDeptNo = command.Parameters.Add("deptno", PgSqlType.Int);
      pDeptName = command.Parameters.Add("deptname", PgSqlType.VarChar, 12);
      pDeptLoc = command.Parameters.Add("loc", PgSqlType.VarChar, 13);

      pDeptNo.Direction = ParameterDirection.ReturnValue;
      pDeptName.Direction = ParameterDirection.ReturnValue;
      pDeptLoc.Direction = ParameterDirection.ReturnValue;

      command.ExecuteNonQuery();
      connection.Close();

      Console.Write("deptno = {0}, deptname = {1}, loc = {2}", pDeptNo.Value, pDeptName.Value, pDeptLoc.Value);
      Console.ReadLine();
    }
  }
}
Imports Devart.Data.PostgreSql

Module Module1

  Sub Main()
    Dim connection As PgSqlConnection = New PgSqlConnection("host=server;database=testdb;user=postgres;")
    Dim command As PgSqlCommand
    Dim pDeptNo, pDeptName, pDeptLoc As PgSqlParameter

    connection.Open()
    command = connection.CreateCommand()
    command.CommandText = "getdept"
    command.CommandType = CommandType.StoredProcedure

    pDeptNo = command.Parameters.Add("deptno", PgSqlType.Int)
    pDeptName = command.Parameters.Add("deptname", PgSqlType.VarChar, 12)
    pDeptLoc = command.Parameters.Add("loc", PgSqlType.VarChar, 13)

    pDeptNo.Direction = ParameterDirection.ReturnValue
    pDeptName.Direction = ParameterDirection.ReturnValue
    pDeptLoc.Direction = ParameterDirection.ReturnValue

    command.ExecuteNonQuery()
    connection.Close()

    Console.Write("deptno = {0}, deptname = {1}, loc = {2}", pDeptNo.Value, pDeptName.Value, pDeptLoc.Value)
    Console.ReadLine()
  End Sub
End Module
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

See Also