Home » Documentation » Class Reference » CDbDataReader

CDbDataReader

Package	system.db
Inheritance	class CDbDataReader » CComponent
Implements	Iterator, Traversable
Since	1.0
Version	$Id: CDbDataReader.php 1678 2010-01-07 21:02:00Z qiang.xue $

CDbDataReader represents a forward-only stream of rows from a query result set.

To read the current row of data, call read. The method readAll returns all the rows in a single array.

One can also retrieve the rows of data in CDbDataReader by using foreach:

foreach($reader as $row)
    // $row represents a row of data

Since CDbDataReader is a forward-only stream, you can only traverse it once.

It is possible to use a specific mode of data fetching by setting FetchMode. See http://www.php.net/manual/en/function.PDOStatement-setFetchMode.php for more details.

Public Properties

Hide inherited properties

Property	Type	Description	Defined By
columnCount	int	the number of columns in the result set.	CDbDataReader
isClosed	boolean	whether the reader is closed or not.	CDbDataReader
rowCount	int	number of rows contained in the result.	CDbDataReader

Public Methods

Hide inherited methods

Method	Description	Defined By
__call()	Calls the named method which is not a class method.	CComponent
__construct()	Constructor.	CDbDataReader
__get()	Returns a property value, an event handler list or a behavior based on its name.	CComponent
__isset()	Checks if a property value is null.	CComponent
__set()	Sets value of a component property.	CComponent
__unset()	Sets a component property to be null.	CComponent
asa()	Returns the named behavior object.	CComponent
attachBehavior()	Attaches a behavior to this component.	CComponent
attachBehaviors()	Attaches a list of behaviors to the component.	CComponent
attachEventHandler()	Attaches an event handler to an event.	CComponent
bindColumn()	Binds a column to a PHP variable.	CDbDataReader
canGetProperty()	Determines whether a property can be read.	CComponent
canSetProperty()	Determines whether a property can be set.	CComponent
close()	Closes the reader.	CDbDataReader
current()	Returns the current row.	CDbDataReader
detachBehavior()	Detaches a behavior from the component.	CComponent
detachBehaviors()	Detaches all behaviors from the component.	CComponent
detachEventHandler()	Detaches an existing event handler.	CComponent
disableBehavior()	Disables an attached behavior.	CComponent
disableBehaviors()	Disables all behaviors attached to this component.	CComponent
enableBehavior()	Enables an attached behavior.	CComponent
enableBehaviors()	Enables all behaviors attached to this component.	CComponent
evaluateExpression()	Evaluates a PHP expression or callback under the context of this component.	CComponent
getColumnCount()		CDbDataReader
getEventHandlers()	Returns the list of attached event handlers for an event.	CComponent
getIsClosed()		CDbDataReader
getRowCount()		CDbDataReader
hasEvent()	Determines whether an event is defined.	CComponent
hasEventHandler()	Checks whether the named event has attached handlers.	CComponent
hasProperty()	Determines whether a property is defined.	CComponent
key()	Returns the index of the current row.	CDbDataReader
next()	Moves the internal pointer to the next row.	CDbDataReader
nextResult()	Advances the reader to the next result when reading the results of a batch of statements.	CDbDataReader
raiseEvent()	Raises an event.	CComponent
read()	Advances the reader to the next row in a result set.	CDbDataReader
readAll()	Reads the whole result set into an array.	CDbDataReader
readColumn()	Returns a single column from the next row of a result set.	CDbDataReader
readObject()	Returns an object populated with the next row of data.	CDbDataReader
rewind()	Resets the iterator to the initial state.	CDbDataReader
setFetchMode()		CDbDataReader
valid()	Returns whether there is a row of data at current position.	CDbDataReader

Property Details

columnCount property read-only

public int getColumnCount()

the number of columns in the result set. Note, even there's no row in the reader, this still gives correct column number.

isClosed property read-only

public boolean getIsClosed()

whether the reader is closed or not.

rowCount property read-only

public int getRowCount()

number of rows contained in the result. Note, most DBMS may not give a meaningful count. In this case, use "SELECT COUNT(*) FROM tableName" to obtain the number of rows.

Method Details

__construct() method

public void __construct(CDbCommand $command)
$command	CDbCommand	the command generating the query result

Constructor.

bindColumn() method

public void bindColumn(mixed $column, mixed $value, int $dataType=NULL)
$column	mixed	Number of the column (1-indexed) or name of the column in the result set. If using the column name, be aware that the name should match the case of the column, as returned by the driver.
$value	mixed	Name of the PHP variable to which the column will be bound.
$dataType	int	Data type of the parameter

Binds a column to a PHP variable. When rows of data are being fetched, the corresponding column value will be set in the variable. Note, the fetch mode must include PDO::FETCH_BOUND.

public integer key()
{return}	integer	the index of the current row.

public array\|false read()
{return}	array\|false	the current row, false if no more row available

public array readAll()
{return}	array	the result set (each array element represents a row of data). An empty array will be returned if the result contains no row.

public mixed\|false readColumn(int $columnIndex)
$columnIndex	int	zero-based column index
{return}	mixed\|false	the column of the current row, false if no more row available

public mixed\|false readObject(string $className, array $fields)
$className	string	class name of the object to be created and populated
$fields	array	Elements of this array are passed to the constructor
{return}	mixed\|false	the populated object, false if no more row of data available