1. Database APIs and Wrappers
MySQL, MySQLi, PDO, PG, OCI, SQLSRV
Web Development Basics
Ivan Yonkov
Technical Trainer
Software University
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2. Table of Contents What is a DB API? Various DB Extensions in PHP
Mysql – deprecated
Mysqli
Pg – Postgre SQL
Oci – Oracle
PDO – Various DB access interface
Using PDO
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3. Database API © Software University Foundation – http://softuni.org
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4. What is Database API?
Database API is the public interface provided to communicate with certain database. It could be a set of functions, classes and methods which perform actions against the database through a desired language.
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5. Various Database Extensions
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6. Various Database API’s
PHP can natively communicate to a lot of databases through its standard library (yet some extensions are required)
MySQL database
Oracle database
Postgre database
SQLite database
MS SQL Server database
Etc…
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7. MySQL Extension
The MySQL Extension is the oldest API for communicating to MySQL Server
It’s been there for more than 15 years (PHP 4.0), marked as deprecated and removed as of PHP 7.0
Uses standard php global functions prefixed with mysql_
Communicates natively with MySQL and sends plain queries
Very vulnerable and error prone
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8. MySQL Extension (2) mysql_connect(“localhost”, “root”, “”, “forum”);
$result = mysql_query(“SELECT * FROM topics”);
while ($row = mysql_fetch_assoc($result)) {
echo $row[‘body’] . “<br />”; }
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9. MySQLi Extension
The MySQLi Extension is the de facto PHP’s standard succeedor of the MySQL extension
Provides both Object oriented and Procedural style
OOP way – the mysqli class.
Procedural – the mysql_ prefix
Still uses old PHP style method naming (under_scored)
Supports a way of parameter binding
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10. MySQLi Extension (2) [Procedural]
$conn = mysqli_connect(“localhost”, “root”, “”, “forum”);
$result = mysqli_query($link, “SELECT * FROM topics”);
while ($row = mysqli_fetch_assoc($result) {
echo $row[‘body’] . “<br/>”; }
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11. MySQLi Extension (3) [OOP]
$mysqli = new mysqli(“localhost”, “root”, “”, “forum”);
$result = $mysqli->query(“SELECT * FROM topics”);
while ($row = $result->fetch_assoc()) {
echo $row[‘body’] . “<br/>”; }
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12. PDO © Software University Foundation – http://softuni.org
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13. PDO
PDO (PHP Data Objects) like Java Data Objects, provides consistent interface for accessing different databases through db drivers
Has full OOP support
Supports prepared statements
Good method naming and consistent objects
Can reuse code after driver changes if the SQL dialect is the same
One can use the same methods no matter the driver
Does not rewrite SQL or missing features
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14. PDO (2)
$dbh = new PDO($dsn, $user, $pass);
The DSN is a connection string providing the driver, host and database name if present.
MySQL dsn: “mysql:host=localhost;dbname=forum”
SQLite dsn
File: “sqlite:/home/royal/databases/sqlite/mysqlitedb.sq3”
Memory: “sqlite::memory:”
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15. PDO (3) $dbh = new PDO( “mysql:host=localhost;dbname=forum”, “root”,“” );
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16. PDO (4) /** @var \PDOStatement $sth */ $id = $_GET[‘id’];
$sth = $db->prepare(“SELECT * FROM topics WHERE id = ?”);
$sth->bindParam(1, $id, PDO::PARAM_INT);
$sth->execute();
$topic = $sth->fetch();
echo $topic[‘body’];
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17. Summary What is a DB API? Various DB Extensions in PHP Using PDO
Using mysql_* extension (don’t)
Using mysqli_* extension
Using PDO
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18. Database APIs and Wrappers
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19. License
This course (slides, examples, demos, videos, homework, etc.) is licensed under the "Creative Commons Attribution- NonCommercial-ShareAlike 4.0 International" license
Attribution: this work may contain portions from
"Fundamentals of Computer Programming with C#" book by Svetlin Nakov & Co. under CC-BY-SA license
"C# Part I" course by Telerik Academy under CC-BY-NC-SA license
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20. Free Trainings @ Software University
Software University Foundation – softuni.org
Software University – High-Quality Education, Profession and Job for Software Developers
softuni.bg
Software Facebook
facebook.com/SoftwareUniversity
Software YouTube
youtube.com/SoftwareUniversity
Software University Forums – forum.softuni.bg
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