Showing entries 1 to 8
Displaying posts with tag: pdo (reset)
Types in PHP and MySQL

Since PHP 7.0 has been released there's more attention on scalar types. Keeping types for data from within your application is relatively simple. But when talking to external systems, like a database things aren't always as one eventually might initially expect.

For MySQL the type we see -- in the first approximation -- is defined by the network protocol. The MySQL network protocol by default converts all data into strings. So if we fetch an integer from the database and use PHP 7's typing feature we get an error:

<?php
declare(strict_types=1);

function getInteger() : int {
  $mysqli = new mysqli(...);
  return $mysqli->query("SELECT 1")->fetch_row()[0];
}

var_dump(getInteger());
?>

Fatal error: Uncaught TypeError: Return value of getInteger() must be of the type integer, string returned in t.php:6

Of course the solution is easy: Either we cast ourselves or we disable the strict mode and PHP will …

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Handling SQL Errors in PDO

I love PHP's PDO (PHP Data Objects) extension; it gives a consistent, object-oriented interface to handling all kinds of relational database backends. One thing that annoys me is that the MySQL driver for PDO defaults to a silent error mode which can make SQL errors tricky to spot!

To give you an example, consider the query below (the correct tablename is country, so this SQL will fail):

$db = new PDO('mysql:host=localhost;dbname=sakila', 'user', 'pass');

$sql = 'select * from countrt';
$stmt = $db->query($sql);

while(($row = $stmt->fetch()) != false) {
    echo $row['country'] . "\n";
}

The script will output an error because $stmt is not an object.

You have a few options here - you can check that you got an object back before you try to do anything with it, for example. Alternatively you can prepare() and then …

[Read more]
Handling SQL Errors in PDO

I love PHP's PDO (PHP Data Objects) extension; it gives a consistent, object-oriented interface to handling all kinds of relational database backends. One thing that annoys me is that the MySQL driver for PDO defaults to a silent error mode which can make SQL errors tricky to spot!

To give you an example, consider the query below (the correct tablename is country, so this SQL will fail):

$db = new PDO('mysql:host=localhost;dbname=sakila', 'user', 'pass');

$sql = 'select * from countrt';
$stmt = $db->query($sql);

while(($row = $stmt->fetch()) != false) {
    echo $row['country'] . "\n";
}

The script will output an error because $stmt is not an object.

You have a few options here - you can check that you got an object back before you try to do anything with it, for example. Alternatively you can prepare() and then …

[Read more]
Scalar type hints in PHP trunk

So in my blog series I try to cover all additions to PHP trunk so I have to mention scalar type hints.

<?php
function print_float(float $f) {
    echo $f."\n";
}

for ($i = 1; $i < 5; $i++) {
    print_float( $i / 3 );
}
?>
        

0.33333333333333
0.66666666666667

Catchable fatal error: Argument 1 passed to print_float() must be of the type double, integer given, called in typehints.php on line 7 and defined in typehints.php on line 2

Is expected behavior in PHP's trunk. If you want such a thing to work please use the numeric type hint.

In case that wasn't enought fun: There's more!

<?php
function handle_result(int $i) {
    echo $i."\n";
}

$pdo = new PDO("mysql:host=localhost;dbname=test", "user", "pass"); …
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Jumpstarting PDO

Lukas is making another attempt at jumpstarting PDO development.  I welcome this effort, and will do what I can to help fill in details and make suggestions.  Unfortunately, I'm just way too busy with work to be able to commit to more than that.

I also wanted to share some of my thoughts on why PDO has been in a holding pattern for a while, so that more people are aware of it and can work to avoid repeating the same mistakes.

The first thing to note is that the guts of PDO were hard to develop.  The PHP script facing API sounds simple enough, but the underlying libraries for each different databases work in different ways, and it was and is a challenge to build PDO in such a way that it can work in the most efficient way.

The second thing, which is really a follow-on from the first, is that the database libraries are complex and nuanced.  …

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Developing MySQL Database Applications With PHP

A four part tutorial that explains the PHP / MySQL extensions - mysql, mysqli, and pdo_mysql - with simple examples is now accessible from Sun Developer Network. While most of the information presented in the tutorial is available elsewhere in bits and pieces, the real value-add is in the introduction of the MySQL native driver for PHP, mysqlnd.

Here is a brief description of all four parts in the series. Check them out, and as always feel free to send the corrections, comments, suggestions, etc., to my Sun mail ID: Giri.Mandalika@Sun.COM

[Read more]
Developing MySQL Database Applications With PHP

A four part tutorial that explains the PHP / MySQL extensions - mysql, mysqli, and pdo_mysql - with simple examples is now accessible from Sun Developer Network. While most of the information presented in the tutorial is available elsewhere in bits and pieces, the real value-add is in the introduction of the MySQL native driver for PHP, mysqlnd.

Here is a brief description of all four parts in the series. Check them out, and as always feel free to send the corrections, comments, suggestions, etc., to my Sun mail ID: Giri.Mandalika@Sun.COM

[Read more]
Developing MySQL Database Applications With PHP

A four part tutorial that explains the PHP / MySQL extensions - mysql, mysqli, and pdo_mysql - with simple examples is now accessible from Sun Developer Network. While most of the information presented in the tutorial is available elsewhere in bits and pieces, the real value-add is in the introduction of the MySQL native driver for PHP, mysqlnd.

Here is a brief description of all four parts in the series. Check them out, and as always feel free to send the corrections, comments, suggestions, etc., to my Sun mail ID: Giri.Mandalika@Sun.COM

[Read more]
Showing entries 1 to 8