New To PHP - Error In My Class

[cyber0ne]

Using PHP 5.1.2

I'm working on a personal project to get used to PHP, and I seem to be
stuck at the moment on a class I'm writing. Here is the code for the
class, with a comment highlighting where it dies when a function is
called externally from the code that instantiates the class:

----------BEGIN PASTE----------
class DataAccess{

private $databaseConnec tion;

function __construct()
{
@ $databaseConnec tion = new mysqli("this", "is", "fake", "data");
if (mysqli_connect _errno())
{
// TODO: generate an error
}
}

function __destruct()
{
$databaseConnec tion->close();
}

function GetArticlesForC ategory($cid)
{
$querySelect = "SELECT stuff WHERE something = " . $cid;

// Testing shows that the following line is where the code dies.
$resultSet = $databaseConnec tion->query($querySe lect);
// End dying code

if ($resultSet)
{
$rowCount = $resultSet->num_rows;
if ($rowCount 0)
{
$i = 0;
while ($i < $rowCount)
{
$rows[$i] = $resultSet->fetch_assoc( );
$i++;
}
$resultSet->free();
return $rows;
}
else
{
// TODO: report an empty set
$resultSet->free();
return;
}
}
else
{
// TODO: generate an error
$resultSet->free();
return;
}
}

}
------------END PASTE------------

The error log seems to be claiming that $databaseConnec tion is
undefined on that line of code. Is there maybe something syntactic
that I'm missing? I've tried replacing all 3 references to
$databaseConnec tion in the class functions with
$this->$databaseConne ction, but that didn't seem to change anything.

Any ideas?

[Tim Hunt]

cyber0ne wrote:

Using PHP 5.1.2

I'm working on a personal project to get used to PHP, and I seem to be
stuck at the moment on a class I'm writing. Here is the code for the
class, with a comment highlighting where it dies when a function is
called externally from the code that instantiates the class:

----------BEGIN PASTE----------
class DataAccess{

private $databaseConnec tion;

function __construct()
{
@ $databaseConnec tion = new mysqli("this", "is", "fake", "data");
if (mysqli_connect _errno())
{
// TODO: generate an error
}
}

function __destruct()
{
$databaseConnec tion->close();
}

function GetArticlesForC ategory($cid)
{
$querySelect = "SELECT stuff WHERE something = " . $cid;

// Testing shows that the following line is where the code dies.
$resultSet = $databaseConnec tion->query($querySe lect);
// End dying code

if ($resultSet)
{
$rowCount = $resultSet->num_rows;
if ($rowCount 0)
{
$i = 0;
while ($i < $rowCount)
{
$rows[$i] = $resultSet->fetch_assoc( );
$i++;
}
$resultSet->free();
return $rows;
}
else
{
// TODO: report an empty set
$resultSet->free();
return;
}
}
else
{
// TODO: generate an error
$resultSet->free();
return;
}
}

}
------------END PASTE------------

The error log seems to be claiming that $databaseConnec tion is
undefined on that line of code. Is there maybe something syntactic
that I'm missing? I've tried replacing all 3 references to
$databaseConnec tion in the class functions with
$this->$databaseConne ction, but that didn't seem to change anything.

Any ideas?

You have to use $this->... to access class properties

And...

@ $databaseConnec tion = new mysqli("this", "is", "fake", "data");
if (mysqli_connect _errno())
{
// TODO: generate an error
}
}

How can you tell if an error occurs if the mysqli error message's are
being displayed and php errors are suppressed for 'new mysqli'?

Replace every $databaseConnec tion with $this->databaseConnec tion,
replace TODO with echo mysql_connect_e rror() and remove the @ from
$databaseConnec tion.

Tim

[B.r.K.o.N.j.A]

cyber0ne wrote:

Using PHP 5.1.2

I'm working on a personal project to get used to PHP, and I seem to be
stuck at the moment on a class I'm writing. Here is the code for the
class, with a comment highlighting where it dies when a function is
called externally from the code that instantiates the class:

----------BEGIN PASTE----------
class DataAccess{

private $databaseConnec tion;

function __construct()
{
@ $databaseConnec tion = new mysqli("this", "is", "fake", "data");
if (mysqli_connect _errno())
{
// TODO: generate an error
}
}

function __destruct()
{
$databaseConnec tion->close();
}

function GetArticlesForC ategory($cid)
{
$querySelect = "SELECT stuff WHERE something = " . $cid;

// Testing shows that the following line is where the code dies.
$resultSet = $databaseConnec tion->query($querySe lect);
// End dying code

if ($resultSet)
{
$rowCount = $resultSet->num_rows;
if ($rowCount 0)
{
$i = 0;
while ($i < $rowCount)
{
$rows[$i] = $resultSet->fetch_assoc( );
$i++;
}
$resultSet->free();
return $rows;
}
else
{
// TODO: report an empty set
$resultSet->free();
return;
}
}
else
{
// TODO: generate an error
$resultSet->free();
return;
}
}

}
------------END PASTE------------

The error log seems to be claiming that $databaseConnec tion is
undefined on that line of code. Is there maybe something syntactic
that I'm missing? I've tried replacing all 3 references to
$databaseConnec tion in the class functions with
$this->$databaseConne ction, but that didn't seem to change anything.

Any ideas?

the way you did it in constructor the variable databaseConnect ion has
scope only in that particular method, you should use

@ $this->databaseConnec tion = new mysqli("this", "is", "fake", "data");

and allways reference that property via $this->databaseConnec ion...

you were using local variables where you really needed class properties
--

B.r.K.o.N.j.A = Bionic Robotic Knight Optimized for Nocturnal Judo and
Assasination

[cyber0ne]

Replace every $databaseConnec tion with $this->databaseConnec tion

I guess it was a syntax thing :) I was trying the following:

$databaseConnec tion
or
$this->$databaseConne ction

But I just got rid of that second $ where applicable and it seems to be
working now. Thanks!