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OleDbCommand Class

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

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.

  NameDescription
Public methodOleDbCommand()Initializes a new instance of the OleDbCommand class.
Public methodOleDbCommand(String)Initializes a new instance of the OleDbCommand class with the text of the query.
Public methodOleDbCommand(String, OleDbConnection)Initializes a new instance of the OleDbCommand class with the text of the query and an OleDbConnection.
Public methodOleDbCommand(String, OleDbConnection, OleDbTransaction)Initializes a new instance of the OleDbCommand class with the text of the query, an OleDbConnection, and the Transaction.
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  NameDescription
Protected propertyCanRaiseEventsGets a value indicating whether the component can raise an event. (Inherited from Component.)
Public propertyCommandTextGets or sets the SQL statement or stored procedure to execute at the data source. (Overrides DbCommand.CommandText.)
Public propertyCommandTimeoutGets or sets the wait time before terminating an attempt to execute a command and generating an error. (Overrides DbCommand.CommandTimeout.)
Public propertyCommandTypeGets or sets a value that indicates how the CommandText property is interpreted. (Overrides DbCommand.CommandType.)
Public propertyConnectionGets or sets the OleDbConnection used by this instance of the OleDbCommand.
Public propertyContainerGets the IContainer that contains the Component. (Inherited from Component.)
Protected propertyDbConnectionGets or sets the DbConnection used by this DbCommand. (Inherited from DbCommand.)
Protected propertyDbParameterCollectionGets the collection of DbParameter objects. (Inherited from DbCommand.)
Protected propertyDbTransactionGets or sets the DbTransaction within which this DbCommand object executes. (Inherited from DbCommand.)
Protected propertyDesignModeGets a value that indicates whether the Component is currently in design mode. (Inherited from Component.)
Public propertyDesignTimeVisibleGets or sets a value that indicates whether the command object should be visible in a customized Windows Forms Designer control. (Overrides DbCommand.DesignTimeVisible.)
Protected propertyEventsGets the list of event handlers that are attached to this Component. (Inherited from Component.)
Public propertyParametersGets the OleDbParameterCollection.
Public propertySiteGets or sets the ISite of the Component. (Inherited from Component.)
Public propertyTransactionGets or sets the OleDbTransaction within which the OleDbCommand executes.
Public propertyUpdatedRowSourceGets or sets how command results are applied to the DataRow when used by the Update method of the OleDbDataAdapter. (Overrides DbCommand.UpdatedRowSource.)
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  NameDescription
Public methodCancelTries to cancel the execution of an OleDbCommand. (Overrides DbCommand.Cancel().)
Public methodCloneCreates a new OleDbCommand object that is a copy of the current instance.
Protected methodCreateDbParameterCreates a new instance of a DbParameter object. (Inherited from DbCommand.)
Public methodCreateObjRefCreates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from MarshalByRefObject.)
Public methodCreateParameterCreates a new instance of an OleDbParameter object.
Public methodDispose()Releases all resources used by the Component. (Inherited from Component.)
Protected methodDispose(Boolean)Releases the unmanaged resources used by the Component and optionally releases the managed resources. (Inherited from Component.)
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodExecuteDbDataReaderExecutes the command text against the connection. (Inherited from DbCommand.)
Public methodExecuteNonQueryExecutes an SQL statement against the Connection and returns the number of rows affected. (Overrides DbCommand.ExecuteNonQuery().)
Public methodExecuteReader()Sends the CommandText to the Connection and builds an OleDbDataReader.
Public methodExecuteReader(CommandBehavior)Sends the CommandText to the Connection, and builds an OleDbDataReader using one of the CommandBehavior values.
Public methodExecuteScalarExecutes 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 methodFinalizeReleases unmanaged resources and performs other cleanup operations before the Component is reclaimed by garbage collection. (Inherited from Component.)
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetLifetimeServiceRetrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
Protected methodGetServiceReturns an object that represents a service provided by the Component or by its Container. (Inherited from Component.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodInitializeLifetimeServiceObtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
Protected methodMemberwiseClone()Creates a shallow copy of the current Object. (Inherited from Object.)
Protected methodMemberwiseClone(Boolean)Creates a shallow copy of the current MarshalByRefObject object. (Inherited from MarshalByRefObject.)
Public methodPrepareCreates a prepared (or compiled) version of the command on the data source. (Overrides DbCommand.Prepare().)
Public methodResetCommandTimeoutResets the CommandTimeout property to the default value.
Public methodToStringReturns a String containing the name of the Component, if any. This method should not be overridden. (Inherited from Component.)
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  NameDescription
Public eventDisposedOccurs when the component is disposed by a call to the Dispose method. (Inherited from Component.)
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  NameDescription
Explicit interface implemetationPrivate methodICloneable.CloneFor a description of this member, see ICloneable.Clone.
Explicit interface implemetationPrivate propertyIDbCommand.ConnectionGets or sets the IDbConnection used by this instance of the IDbCommand. (Inherited from DbCommand.)
Explicit interface implemetationPrivate methodIDbCommand.CreateParameterCreates a new instance of an IDbDataParameter object. (Inherited from DbCommand.)
Explicit interface implemetationPrivate methodIDbCommand.ExecuteReader()For a description of this member, see IDbCommand.ExecuteReader.
Explicit interface implemetationPrivate methodIDbCommand.ExecuteReader(CommandBehavior)Executes the CommandText against the Connection, and builds an IDataReader using one of the CommandBehavior values.
Explicit interface implemetationPrivate propertyIDbCommand.ParametersGets the IDataParameterCollection. (Inherited from DbCommand.)
Explicit interface implemetationPrivate propertyIDbCommand.TransactionGets or sets the DbTransaction within which this DbCommand object executes. (Inherited from DbCommand.)
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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.

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