Lesson 17 / 25
PDO and databases
Explain PDO and databases, run a small example, and check the result.
The essential idea
PDO and databases is easiest when you first identify its job. Name the input, the change, and the result before memorising syntax. Small explicit steps make programs easier to repair later.
Run a tiny experiment
This idea is one part of the path from a source file to useful output.
<?php
// Explore database one small step at a time.
$value = 0;
echo $value, PHP_EOL;
Output:
0
A common trap
Do not trust code just because it looks familiar. For PDO and databases, change one value, run the smallest example, and compare the result with your prediction.
Quick check
Quick check: What is the best first practice for PDO and databases?
- Run one small, focused example.
- Memorize syntax without testing it.
- Ignore error messages.
Answer
Run one small, focused example. — A small experiment gives direct feedback about cause and effect.