OleDbCommand Class
Represents an SQL statement or stored procedure to execute against a data source.
Assembly: System.Data (in System.Data.dll)
System::MarshalByRefObject
System.ComponentModel::Component
System.Data.Common::DbCommand
System.Data.OleDb::OleDbCommand
| Name | Description | |
|---|---|---|
 | OleDbCommand() | Initializes a new instance of the OleDbCommand class. |
| OleDbCommand(String^) | Initializes a new instance of the OleDbCommand class with the text of the query. |
| OleDbCommand(String^, OleDbConnection^) | Initializes a new instance of the OleDbCommand class with the text of the query and an OleDbConnection. |
| OleDbCommand(String^, OleDbConnection^, OleDbTransaction^) | Initializes a new instance of the OleDbCommand class with the text of the query, an OleDbConnection, and the Transaction. |
| Name | Description | |
|---|---|---|
 | CommandText | Gets or sets the SQL statement or stored procedure to execute at the data source.(Overrides DbCommand::CommandText.) |
| CommandTimeout | Gets or sets the wait time before terminating an attempt to execute a command and generating an error.(Overrides DbCommand::CommandTimeout.) |
| CommandType | Gets or sets a value that indicates how the CommandText property is interpreted.(Overrides DbCommand::CommandType.) |
| Connection | Gets or sets the OleDbConnection used by this instance of the OleDbCommand. |
| Container | Gets the IContainer that contains the Component.(Inherited from Component.) |
| 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.) |
| Parameters | Gets the OleDbParameterCollection. |
| Site | |
| Transaction | Gets or sets the OleDbTransaction within which the OleDbCommand executes. |
| UpdatedRowSource | Gets or sets how command results are applied to the DataRow when used by the Update method of the OleDbDataAdapter.(Overrides DbCommand::UpdatedRowSource.) |
| Name | Description | |
|---|---|---|
| Cancel() | Tries to cancel the execution of an OleDbCommand.(Overrides DbCommand::Cancel().) |
| Clone() | Creates a new OleDbCommand object that is a copy of the current instance. |
| CreateObjRef(Type^) | Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object.(Inherited from MarshalByRefObject.) |
| CreateParameter() | Creates a new instance of an OleDbParameter object. |
| Dispose() | |
| Equals(Object^) | Determines whether the specified object is equal to the current object.(Inherited from Object.) |
| ExecuteNonQuery() | Executes an SQL statement against the Connection and returns the number of rows affected.(Overrides DbCommand::ExecuteNonQuery().) |
| ExecuteNonQueryAsync() | An asynchronous version of ExecuteNonQuery, which executes a SQL statement against a connection object. Invokes ExecuteNonQueryAsync with CancellationToken.None.(Inherited from DbCommand.) |
| ExecuteNonQueryAsync(CancellationToken) | This is the asynchronous version of ExecuteNonQuery. Providers should override with an appropriate implementation. The cancellation token may optionally be ignored. The default implementation invokes the synchronous ExecuteNonQuery method and returns a completed task, blocking the calling thread. The default implementation will return a cancelled task if passed an already cancelled cancellation token. Exceptions thrown by ExecuteNonQuery will be communicated via the returned Task Exception property. Do not invoke other methods and properties of the DbCommand object until the returned Task is complete.(Inherited from DbCommand.) |
| ExecuteReader() | Sends the CommandText to the Connection and builds an OleDbDataReader. |
| ExecuteReader(CommandBehavior) | Sends the CommandText to the Connection, and builds an OleDbDataReader using one of the CommandBehavior values. |
| ExecuteReaderAsync() | An asynchronous version of ExecuteReader, which executes the CommandText against the Connection and returns a DbDataReader. Invokes ExecuteDbDataReaderAsync with CancellationToken.None.(Inherited from DbCommand.) |
| ExecuteReaderAsync(CancellationToken) | An asynchronous version of ExecuteReader, which executes the CommandText against the Connection and returns a DbDataReader. This method propagates a notification that operations should be canceled. Invokes ExecuteDbDataReaderAsync.(Inherited from DbCommand.) |
| ExecuteReaderAsync(CommandBehavior) | An asynchronous version of ExecuteReader, which executes the CommandText against the Connection and returns a DbDataReader. Invokes ExecuteDbDataReaderAsync.(Inherited from DbCommand.) |
| ExecuteReaderAsync(CommandBehavior, CancellationToken) | Invokes ExecuteDbDataReaderAsync.(Inherited from DbCommand.) |
| 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().) |
| ExecuteScalarAsync() | An asynchronous version of ExecuteScalar, which executes the query and returns the first column of the first row in the result set returned by the query. All other columns and rows are ignored. Invokes ExecuteScalarAsync with CancellationToken.None.(Inherited from DbCommand.) |
| ExecuteScalarAsync(CancellationToken) | This is the asynchronous version of ExecuteScalar. Providers should override with an appropriate implementation. The cancellation token may optionally be ignored. The default implementation invokes the synchronous ExecuteScalar method and returns a completed task, blocking the calling thread. The default implementation will return a cancelled task if passed an already cancelled cancellation token. Exceptions thrown by ExecuteScalar will be communicated via the returned Task Exception property. Do not invoke other methods and properties of the DbCommand object until the returned Task is complete.(Inherited from DbCommand.) |
| GetHashCode() | Serves as the default hash function. (Inherited from Object.) |
| GetLifetimeService() | Retrieves the current lifetime service object that controls the lifetime policy for this instance.(Inherited from MarshalByRefObject.) |
| GetType() | |
| InitializeLifetimeService() | Obtains a lifetime service object to control the lifetime policy for this instance.(Inherited from MarshalByRefObject.) |
| Prepare() | Creates a prepared (or compiled) version of the command on the data source.(Overrides DbCommand::Prepare().) |
| ResetCommandTimeout() | Resets the CommandTimeout property to the default value. |
| ToString() |
| Name | Description | |
|---|---|---|
  | IDbCommand::CreateParameter() | Creates a new instance of an IDbDataParameter object.(Inherited from DbCommand.) |
| IDbCommand::ExecuteReader() | For a description of this member, see IDbCommand::ExecuteReader. |
| IDbCommand::ExecuteReader(CommandBehavior) | Executes the CommandText against the Connection, and builds an IDataReader using one of the CommandBehavior values. |
| ICloneable::Clone() | For a description of this member, see ICloneable::Clone. |
 | IDbCommand::Connection | Gets or sets the IDbConnection used by this instance of the IDbCommand.(Inherited from DbCommand.) |
| IDbCommand::Parameters | Gets the IDataParameterCollection.(Inherited from DbCommand.) |
| IDbCommand::Transaction | Gets or sets the DbTransaction within which this DbCommand object executes.(Inherited from DbCommand.) |
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 |
|---|---|
Executes commands that return rows. ExecuteReader may not have the effect that you want if used to execute commands such as SQL SET statements. | |
Executes commands such as SQL INSERT, DELETE, UPDATE, and SET statements. | |
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.
Available since 1.1
Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.