This topic has not yet been rated - Rate this topic

OleDbCommand Class

Represents an SQL statement or stored procedure to execute against a data source.

System.Object
  System.MarshalByRefObject
    System.ComponentModel.Component
      System.Data.Common.DbCommand
        System.Data.OleDb.OleDbCommand

Namespace:  System.Data.OleDb
Assembly:  System.Data (in System.Data.dll)
public sealed class OleDbCommand : DbCommand, 
	ICloneable, IDbCommand, IDisposable

The OleDbCommand type exposes the following members.

  Name Description
Public method OleDbCommand() Initializes a new instance of the OleDbCommand class.
Public method OleDbCommand(String) Initializes a new instance of the OleDbCommand class with the text of the query.
Public method OleDbCommand(String, OleDbConnection) Initializes a new instance of the OleDbCommand class with the text of the query and an OleDbConnection.
Public method OleDbCommand(String, OleDbConnection, OleDbTransaction) Initializes a new instance of the OleDbCommand class with the text of the query, an OleDbConnection, and the Transaction.
Top
  Name Description
Protected property CanRaiseEvents Gets a value indicating whether the component can raise an event. (Inherited from Component.)
Public property CommandText Gets or sets the SQL statement or stored procedure to execute at the data source. (Overrides DbCommand.CommandText.)
Public property CommandTimeout Gets or sets the wait time before terminating an attempt to execute a command and generating an error. (Overrides DbCommand.CommandTimeout.)
Public property CommandType Gets or sets a value that indicates how the CommandText property is interpreted. (Overrides DbCommand.CommandType.)
Public property Connection Gets or sets the OleDbConnection used by this instance of the OleDbCommand.
Public property Container Gets the IContainer that contains the Component. (Inherited from Component.)
Protected property DbConnection Gets or sets the DbConnection used by this DbCommand. (Inherited from DbCommand.)
Protected property DbParameterCollection Gets the collection of DbParameter objects. (Inherited from DbCommand.)
Protected property DbTransaction Gets or sets the DbTransaction within which this DbCommand object executes. (Inherited from DbCommand.)
Protected property DesignMode Gets a value that indicates whether the Component is currently in design mode. (Inherited from Component.)
Public property DesignTimeVisible Gets or sets a value that indicates whether the command object should be visible in a customized Windows Forms Designer control. (Overrides DbCommand.DesignTimeVisible.)
Protected property Events Gets the list of event handlers that are attached to this Component. (Inherited from Component.)
Public property Parameters Gets the OleDbParameterCollection.
Public property Site Gets or sets the ISite of the Component. (Inherited from Component.)
Public property Transaction Gets or sets the OleDbTransaction within which the OleDbCommand executes.
Public property UpdatedRowSource Gets or sets how command results are applied to the DataRow when used by the Update method of the OleDbDataAdapter. (Overrides DbCommand.UpdatedRowSource.)
Top
  Name Description
Public method Cancel Tries to cancel the execution of an OleDbCommand. (Overrides DbCommand.Cancel().)
Public method Clone Creates a new OleDbCommand object that is a copy of the current instance.
Protected method CreateDbParameter Creates a new instance of a DbParameter object. (Inherited from DbCommand.)
Public method CreateObjRef Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from MarshalByRefObject.)
Public method CreateParameter Creates a new instance of an OleDbParameter object.
Public method Dispose() Releases all resources used by the Component. (Inherited from Component.)
Protected method Dispose(Boolean) Releases the unmanaged resources used by the Component and optionally releases the managed resources. (Inherited from Component.)
Public method Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected method ExecuteDbDataReader Executes the command text against the connection. (Inherited from DbCommand.)
Public method ExecuteNonQuery Executes an SQL statement against the Connection and returns the number of rows affected. (Overrides DbCommand.ExecuteNonQuery().)
Public method ExecuteReader() Sends the CommandText to the Connection and builds an OleDbDataReader.
Public method ExecuteReader(CommandBehavior) Sends the CommandText to the Connection, and builds an OleDbDataReader using one of the CommandBehavior values.
Public method ExecuteScalar Executes the query, and returns the first column of the first row in the result set returned by the query. Additional columns or rows are ignored. (Overrides DbCommand.ExecuteScalar().)
Protected method Finalize Releases unmanaged resources and performs other cleanup operations before the Component is reclaimed by garbage collection. (Inherited from Component.)
Public method GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
Public method GetLifetimeService Retrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
Protected method GetService Returns an object that represents a service provided by the Component or by its Container. (Inherited from Component.)
Public method GetType Gets the Type of the current instance. (Inherited from Object.)
Public method InitializeLifetimeService Obtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
Protected method MemberwiseClone() Creates a shallow copy of the current Object. (Inherited from Object.)
Protected method MemberwiseClone(Boolean) Creates a shallow copy of the current MarshalByRefObject object. (Inherited from MarshalByRefObject.)
Public method Prepare Creates a prepared (or compiled) version of the command on the data source. (Overrides DbCommand.Prepare().)
Public method ResetCommandTimeout Resets the CommandTimeout property to the default value.
Public method ToString Returns a String containing the name of the Component, if any. This method should not be overridden. (Inherited from Component.)
Top
  Name Description
Public event Disposed Occurs when the component is disposed by a call to the Dispose method. (Inherited from Component.)
Top
  Name Description
Explicit interface implemetation Private method ICloneable.Clone For a description of this member, see ICloneable.Clone.
Explicit interface implemetation Private property IDbCommand.Connection Gets or sets the IDbConnection used by this instance of the IDbCommand. (Inherited from DbCommand.)
Explicit interface implemetation Private method IDbCommand.CreateParameter Creates a new instance of an IDbDataParameter object. (Inherited from DbCommand.)
Explicit interface implemetation Private method IDbCommand.ExecuteReader() For a description of this member, see IDbCommand.ExecuteReader.
Explicit interface implemetation Private method IDbCommand.ExecuteReader(CommandBehavior) Executes the CommandText against the Connection, and builds an IDataReader using one of the CommandBehavior values.
Explicit interface implemetation Private property IDbCommand.Parameters Gets the IDataParameterCollection. (Inherited from DbCommand.)
Explicit interface implemetation Private property IDbCommand.Transaction Gets or sets the DbTransaction within which this DbCommand object executes. (Inherited from DbCommand.)
Top

When an instance of OleDbCommand is created, the read/write properties are set to their initial values. For a list of these values, see the OleDbCommand constructor.

OleDbCommand features the following methods executing commands at a data source:

Item

Description

ExecuteReader

Executes commands that return rows. ExecuteReader may not have the effect that you want if used to execute commands such as SQL SET statements.

ExecuteNonQuery

Executes commands such as SQL INSERT, DELETE, UPDATE, and SET statements.

ExecuteScalar

Retrieves a single value, for example, an aggregate value from a database.

You can reset the CommandText property and reuse the OleDbCommand object. However, you must close the OleDbDataReader before you can execute a new or previous command.

If a fatal OleDbException (for example, a SQL Server severity level of 20 or greater) is generated by the method executing an OleDbCommand, the OleDbConnection, the connection may be closed. However, the user can reopen the connection and continue.

The following example uses the OleDbCommand, along OleDbDataAdapter and OleDbConnection, to select rows from an Access database. The filled DataSet is then returned. The example is passed an initialized DataSet, a connection string, a query string that is an SQL SELECT statement, and a string that is the name of the source database table.


public void ReadMyData(string connectionString)
{
    string queryString = "SELECT OrderID, CustomerID FROM Orders";
    using (OleDbConnection connection = new OleDbConnection(connectionString))
    {
        OleDbCommand command = new OleDbCommand(queryString, connection);
        connection.Open();
        OleDbDataReader reader = command.ExecuteReader();

        while (reader.Read())
        {
            Console.WriteLine(reader.GetInt32(0) + ", " + reader.GetString(1));
        }
        // always call Close when done reading.
        reader.Close();
    }
}


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Did you find this helpful?
(1500 characters remaining)
Community Content Add
Annotations FAQ