PHP Data Objects

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User Contributed Notes 4 notes

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125
djlopez at gmx dot de
18 years ago
Please note this:

Won't work:
$sth = $dbh->prepare('SELECT name, colour, calories FROM ? WHERE calories < ?');

THIS WORKS!
$sth = $dbh->prepare('SELECT name, colour, calories FROM fruit WHERE calories < ?');

The parameter cannot be applied on table names!!
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6
wiserufferto at gmail dot com
3 years ago
This is a little late... but I'm old and slow.......
Regarding Extending PDOStatement and PDO I found that sending the PDOExtended class by reference helps:
In the constructor after parent::__construct() :
$this->setAttribute(\PDO::ATTR_STATEMENT_CLASS,array('PDOStatementExtended', [&$this]));}

And in
class PDOStatementExtended extends \PDOStatement
{

protected function __construct
(
\PDO &$PDO,
)
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9
pokojny at radlight dot com
18 years ago
I wanted to extend PDO class to store statistics of DB usage, and I faced some problems. I wanted to count number of created statements and number of their executings. So PDOStatement should have link to PDO that created it and stores the statistical info. The problem was that I didn't knew how PDO creates PDOStatement (constructor parameters and so on), so I have created these two classes:

<?php
/**
* PHP Document Object plus
*
* PHP Document Object plus is library with functionality of PDO, entirely written
* in PHP, so that developer can easily extend it's classes with specific functionality,
* such as providing database usage statistics implemented in v1.0b
*
* @author Peter Pokojny
* @license http://opensource.org/licenses/gpl-license.php GNU Public License
*/
class PDOp {
protected
$PDO;
public
$numExecutes;
public
$numStatements;
public function
__construct($dsn, $user=NULL, $pass=NULL, $driver_options=NULL) {
$this->PDO = new PDO($dsn, $user, $pass, $driver_options);
$this->numExecutes = 0;
$this->numStatements = 0;
}
public function
__call($func, $args) {
return
call_user_func_array(array(&$this->PDO, $func), $args);
}
public function
prepare() {
$this->numStatements++;

$args = func_get_args();
$PDOS = call_user_func_array(array(&$this->PDO, 'prepare'), $args);

return new
PDOpStatement($this, $PDOS);
}
public function
query() {
$this->numExecutes++;
$this->numStatements++;

$args = func_get_args();
$PDOS = call_user_func_array(array(&$this->PDO, 'query'), $args);

return new
PDOpStatement($this, $PDOS);
}
public function
exec() {
$this->numExecutes++;

$args = func_get_args();
return
call_user_func_array(array(&$this->PDO, 'exec'), $args);
}
}
class
PDOpStatement implements IteratorAggregate {
protected
$PDOS;
protected
$PDOp;
public function
__construct($PDOp, $PDOS) {
$this->PDOp = $PDOp;
$this->PDOS = $PDOS;
}
public function
__call($func, $args) {
return
call_user_func_array(array(&$this->PDOS, $func), $args);
}
public function
bindColumn($column, &$param, $type=NULL) {
if (
$type === NULL)
$this->PDOS->bindColumn($column, $param);
else
$this->PDOS->bindColumn($column, $param, $type);
}
public function
bindParam($column, &$param, $type=NULL) {
if (
$type === NULL)
$this->PDOS->bindParam($column, $param);
else
$this->PDOS->bindParam($column, $param, $type);
}
public function
execute() {
$this->PDOp->numExecutes++;
$args = func_get_args();
return
call_user_func_array(array(&$this->PDOS, 'execute'), $args);
}
public function
__get($property) {
return
$this->PDOS->$property;
}
public function
getIterator() {
return
$this->PDOS;
}
}
?>

Classes have properties with original PDO and PDOStatement objects, which are providing the functionality to PDOp and PDOpStatement.
From outside, PDOp and PDOpStatement look like PDO and PDOStatement, but also are providing wanted info.
up
-4
www.navin.biz
18 years ago
Below is an example of extending PDO & PDOStatement classes:

<?php

class Database extends PDO
{
function
__construct()
{
parent::__construct('mysql:dbname=test;host=localhost', 'root', '');
$this->setAttribute(PDO::ATTR_STATEMENT_CLASS, array('DBStatement', array($this)));
}
}

class
DBStatement extends PDOStatement
{
public
$dbh;

protected function
__construct($dbh)
{
$this->dbh = $dbh;
$this->setFetchMode(PDO::FETCH_OBJ);
}

public function
foundRows()
{
$rows = $this->dbh->prepare('SELECT found_rows() AS rows', array(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY => TRUE));
$rows->execute();
$rowsCount = $rows->fetch(PDO::FETCH_OBJ)->rows;
$rows->closeCursor();
return
$rowsCount;
}
}

?>
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