ADO » Objects » Command
The ADO Command object is used to submit and execute a specific (single) query against a database. The query can command a variety of actions, such as adding, creating, deleting, retrieving, or updating databases (record sets).
If the query is used to retrieve data, then the data will be returned as a RecordSet object.
This means that the retrieved data can be manipulated by the sixty-four properties, collections, methods,
and events that belong to the Recordset object.
Also with ADO 2.6, the performance of
command queries that only return a single row has been greatly improved.
One of the major features of the Command object is the ability to use stored queries and procedures
that accept parameters.
This requires access to the Parameter collection, which is a collection that is unique to the Command object.
You can also use the Execute method of the Connection object or the
Open method of the RecordSet object to query a database.
However, these queries lack the great versatility offered by the properties, collections, methods,
and events that are associated with the Command object.
(For example, you cannot use parameterized queries.)
Properties
- ActiveConnection
Syntax: Set connectionobject = commandobject. ActiveConnection
Set commandobject.ActiveConnection = connectionobject
commandobject.ActiveConnection = string
string = commandobject.ActiveConnectionSets or returns a variant value defining the Connection object to which the Command object belongs, or returns a string value if there is no connection.
- CommandStream
Syntax: commandobject.CommandStream = string
string = commandobject.CommandStreamIdentifies the Stream object containing the command details.
- CommandText
Syntax: commandobject.CommandText = string
string = commandobject.CommandTextSets or returns the text of a command statement to be applied against a data provider.
- CommandTimeout
Syntax: commandobject.CommandTimeout = long
long = commandobject.CommandTimeoutThe number of seconds to wait while attempting to execute a command, before cancelling the attempt and generating an error.
- CommandType
Syntax: commandobject.CommandType = CommandTypeEnum
CommandTypeEnum = commandobject.CommandTypeSets or returns the CommandTypeEnum type of the Command object.
- Dialect
Syntax: commandobject.Dialect = string
string = commandobject.DialectSets or returns the dialect to be used for the CommandStream or CommandTextproperties.
- Name
Syntax: commandobject.Name = string
string = commandobject.NameSets or returns the string name of the Command object.
- NamedParameters
Syntax: commandobject.NamedParameters = boolean
boolean = commandobject.NamedParametersSets or returns a boolean that determines whether or not parameter names should be passedto the provider.
- Prepared
Syntax: commandobject.Prepared = Boolean
Boolean = commandobject.PreparedSets or returns a Boolean value that indicates whether or not the provider is to save a compiled version of a command before it is executed.
- State
Syntax: long = commandobject.State
Returns a long value describing if the Command object is open, closed or in the process of connecting, executing or retrieving.
Methods
- Cancel
Syntax: commandobject.Cancel
Cancels the execution of a pending Execute call.
- CreateParameter
Syntax: Set parameterobject = commandobject.CreateParameter (Name, Type, Direction, Size, Value)
Creates a new Parameter object.
- Execute
Syntax: Syntax for non-row-returning:
commandobject.Execute RecordsAffected, Parameters, Options
Syntax for row-returning:
Set recordsetobject = commandobject.Execute (RecordsAffected, Parameters, Options)Executes the query, SQL statement or stored procedure.
Collections
- Parameters
The Parameters Collection is a collection of the Parameter objects associated with a specific Command object. Each Parameter object provides detailed information about a single parameter used in a stored procedure or a parameterized query.
- Properties
The Properties Collection is a collection of Property objects. Each Property object contains a single piece of information, called a dynamic property, about the database provider. By referring to the Properties Collection, each connection to a provider can be tailored specifically by ADO to suit the exact needs of that provider.
See Also:
