DB2Command Class

In This Topic

Represents a SQL statement or stored procedure to execute against DB2.

Syntax

Visual Basic
C#

'Declaration
 
Public Class DB2Command 
   Inherits Devart.Common.DbCommandBase
   Implements System.ComponentModel.IComponent, System.Data.IDbCommand, System.ICloneable, System.IDisposable

public class DB2Command : Devart.Common.DbCommandBase, System.ComponentModel.IComponent, System.Data.IDbCommand, System.ICloneable, System.IDisposable

Remarks

The DB2Command class provides the following methods for executing commands against the DB2 database:

Item	Description
ExecuteReader	Executes commands that return rows.
Devart.Common.DbCommandBase.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 DB2Exception, the DB2Connection 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 DB2Command, along with DB2DataReader and DB2Connection, to select rows from a table.

csharp

public void ReadMyData(string myConnString)
{
  string mySelectQuery = "SELECT DeptNo, DName FROM Dept";
  DB2Connection db2Connection = new DB2Connection(myConnString);
  DB2Command db2Command = new DB2Command(mySelectQuery,db2Connection);
  db2Connection.Open();
  DB2DataReader db2Reader = db2Command.ExecuteReader();
  try
  {
    while (db2Reader.Read())
    {
      Console.WriteLine(db2Reader.GetInt32(0).ToString() + ", " + db2Reader.GetString(1));
    }
  }
  finally
  {
  // always call Close when done reading.
  db2Reader.Close();
  // always call Close when done reading.
  db2Connection.Close();
  }
}

Visual Basic

Public Sub ReadMyData(myConnString As String)
  Dim mySelectQuery As String = "SELECT DeptNo, DName FROM Dept"
  Dim db2Connection As New DB2Connection(myConnString)
  Dim db2Command As New DB2Command(mySelectQuery, db2Connection)
  db2Connection.Open()
  Dim db2Reader As DB2DataReader = db2Command.ExecuteReader()
  Try
    While db2Reader.Read()
      Console.WriteLine(db2Reader.GetInt32(0).ToString() + ", " _
        + db2Reader.GetString(1))
    End While
  Finally
      ' always call Close when done reading.
      db2Reader.Close()
      ' always call Close when done with connection.
      db2Connection.Close()
  End Try
End Sub

Inheritance Hierarchy

System.Object
   System.MarshalByRefObject
      System.ComponentModel.Component
         System.Data.Common.DbCommand
            Devart.Common.DbCommandBase
               Devart.Data.DB2.DB2Command

Reference

DB2Command Members
Devart.Data.DB2 Namespace
DB2DataReader Class
DB2Connection Class

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