Can I convert mysql functions to PDO one at a time? - php

Question

I have a bunch of mysql queries in my sight that Im going to need to convert to PDO. Can I do this one query at a time and all other functions continue to work? For example if I convert 1 query to PDO with that hinder all my other mysql queries from working properly?

Answer 1

That should work without any problems as long as you have 2 database connections open, one for the mysql_* functions and one for PDO.
The only potential drawback is the temporary extra overhead of the two db connections instead of one.

Answer 2

I don't see why it would, unless you're using some sort of special database handler class or something.

Answer 3

One thing you might want to consider is not using a "connections" script, but using more of an OOP/data-model setup.
Basically, you keep your connection details in a separate file - mine just defined some constants that I could access later in the script in which it gets included. From there, you create a class that is responsible for establishing it's own connection when instantiated. This class will contain methods that correspond to your typical queries, with maybe a method to run a raw query as needed.
The advantage of doing this is that you can basically leave your existing code alone, and just add your new data model code where you want, as you update or replace your existing scripts.
For reference's sake, here's a stripped down version of code I used to use:
db.php
<?php
# Set the database access information as constants.
DEFINE ('DB_USER', 'your_db_user_name');
DEFINE ('DB_PASSWORD', 'your-super-duper-secret-password');
DEFINE ('DB_HOST', 'localhost');
DEFINE ('DB_NAME', 'schema-name');
DEFINE ('DB_CONNECTION', 'mysql:host=' . DB_HOST . ';dbname=' . DB_NAME );
?>
blog-model.php
<?php
# File: blog-model.php
# Version: 1.0
# Updated: 2011.9.4
# Meta: This file contains the database access information.
# This file also establishes a connection to MySQL and selects the database.
#require_once( ROOT . DS . 'config' . DS . 'db.php' );
# Utility Class
class BlogModel {
protected $pdo;
# Constructor
function __construct() {
$this->connect();
}
function __destruct() {
}
# Connect to the database
function connect() {
# Database connectivity can be a tricky beast, so I'm wrapping the entire block in a try/catch
try {
$this->pdo = new PDO( DB_CONNECTION, DB_USER, DB_PASSWORD, array( PDO::ATTR_PERSISTENT => true ) );
# Set character set to UTF-8 (adds support for non-ASCII languages).
# Note this can cause issues with BLOB-style fields, especially with INSERTs
$this->pdo->exec( "SET CHARACTER SET utf8" );
return true;
}
catch(PDOException $e) {
# Add code to write out error log and alert administrator
trigger_error( "<p>Could not select the database</p>\n<p>MySQL Error: " . $e->getMessage() . "</p>" );
return false;
}
}
# Run an INSERT query; that is, insert a new row (or rows) into a MySQL table
function insert( $authorid, $title, $permalink, $category, $body, $tags, $abstract ) {
try {
# Named parameters (prefered)
$stmt = $this->pdo->prepare(
"INSERT INTO pages
SET title = :title,
permalink = :permalink,
category = :category,
body = :body,
tags = :tags,
abstract = :abstract,
author = :authorid,
timestamp = NOW();"
);
$stmt->bindParam( ':title', $title );
$stmt->bindParam( ':permalink', $permalink );
$stmt->bindParam( ':category', $category );
$stmt->bindParam( ':body', $body );
$stmt->bindParam( ':tags', $tags );
$stmt->bindParam( ':abstract', $abstract );
$stmt->bindParam( ':authorid', $authorid, PDO::PARAM_INT );
return $stmt->execute();
}
catch( Exception $e ) {
# Add code to write out error log and email administrator
trigger_error( "<p>An error occurred whilst executing your query:\n<br />MySQL Error: " . $e->getMessage() . "</p>" );
return false;
}
}
# Run an UPDATE query; that is, update an existing row (or rows) in a MySQL table
function update( $id, $title, $category, $body, $tags, $abstract ) {
try {
# Update the project matching the supplied id
# Named parameters (prefered)
$stmt = $this->pdo->prepare(
"UPDATE pages
SET title = :title, category = :category, body = :body, tags = :tags, abstract = :abstract, lastupdated = NOW()
WHERE permalink = :id
LIMIT 1;"
);
$stmt->bindParam( ':id', $id );
$stmt->bindParam( ':title', $title );
$stmt->bindParam( ':category', $category );
$stmt->bindParam( ':body', $body );
$stmt->bindParam( ':tags', $tags );
$stmt->bindParam( ':abstract', $abstract );
return $stmt->execute();
}
catch( Exception $e ) {
# Add code to write out error log and email administrator
trigger_error( "<p>An error occurred whilst executing your query:\n<br />MySQL Error: " . $e->getMessage() . "</p>" );
return false;
}
}
# Run a DELETE query; that is, remove a record (or records) from a MySQL table
function delete( $id ) {
try {
# Delete the project matching the supplied id
# Named parameters (prefered)
$stmt = $this->pdo->prepare( "DELETE FROM pages WHERE id = :id LIMIT 1;" );
$stmt->bindParam( ':id', $id, PDO::PARAM_INT );
return $stmt->execute();
}
catch( Exception $e ) {
# Add code to write out error log and email administrator
trigger_error( "<p>An error occurred whilst executing your query:\n<br />MySQL Error: " . $e->getMessage() . "</p>" );
return false;
}
}
# Close the connection
function close() {
$this->pdo = null;
}
}
?>
This is all probably not entirely relevant to your original question, but maybe you (or some random Google-er) can derive some use from it.