← PHP theorytheory 0/50 · 0%

level 1

Curious · 0 XP

streak

perfect

badges

100 XP to Apprentice

Database · medium

27. PDO & Prepared Statements

Safe database access.

1 min read2 questionsup to 50 XPtopic 27/50

Read in another language

AI translates the explanation and quiz text while preserving code and answer scoring.

PDO (PHP Data Objects) provides a consistent interface for accessing multiple database systems. Prepared statements, created with $pdo->prepare() and executed with bound parameters, separate SQL logic from data, preventing SQL injection.

Using placeholders (either ? or :name) instead of concatenating user input directly into SQL strings is the standard safe practice for all database queries.

How to study this topic

1. Read the explanation once end to end, skipping the code.
2. Re-read the code snippets and say out loud what each line does.
3. Answer the quiz without scrolling back — that is the real check.
4. Read every explanation, even for the answers you got right.

Scoring

· Up to 30 XP from quiz accuracy.
· +15 XP for a perfect first attempt.
· +5 XP while a 3-day streak is running.
· 75% or higher marks the topic complete.

Check your understanding

1. What primarily protects against SQL injection when using PDO?
Escaping quotes manuallyPrepared statements with bound parametersUsing MySQLi insteadDisabling error reporting
2. Which PDO method compiles a SQL statement with placeholders?
query()exec()prepare()fetch()

Badges

First light

Pass your first topic

Sharp shooter

3 perfect first-try quizzes

On a roll

Study 3 days in a row

Week warrior

Study 7 days in a row

Grinder

Earn 500 XP

Deep diver

Earn 1500 XP