Fetch modes and styles in PHP - Step-by-Step Execution

Concept Flow - Fetch modes and styles

Connect to DB

↓

Execute Query

↓

Fetch Data

↓

Fetch as Associative Array

↓

Fetch as Numeric Array

↓

Fetch as Object

↓

Fetch Both

↓

Fetch into Class

↓

Use Data

This flow shows how after running a query, PHP fetches data in different styles or modes, like arrays or objects, to use in your program.

Execution Sample

PHP

<?php
$stmt = $pdo->query('SELECT id, name FROM users');
$row = $stmt->fetch(PDO::FETCH_ASSOC);
echo $row['name'];
?>

This code fetches one row from the database as an associative array and prints the 'name' field.

Execution Table

Step	Action	Fetch Mode	Data Returned	Output
1	Execute query	-	-	-
2	Fetch first row	PDO::FETCH_ASSOC	{'id' => 1, 'name' => 'Alice'}	Alice
3	Fetch second row	PDO::FETCH_ASSOC	{'id' => 2, 'name' => 'Bob'}	-
4	Fetch third row	PDO::FETCH_ASSOC	false (no more rows)	-

💡 No more rows to fetch, fetch() returns false and loop ends

Variable Tracker

Variable	Start	After Step 2	After Step 3	After Step 4
$row	null	{'id' => 1, 'name' => 'Alice'}	{'id' => 2, 'name' => 'Bob'}	false

Key Moments - 3 Insights

Why does fetch() return false at the end?

fetch() returns false when there are no more rows to get from the query result, as shown in step 4 of the execution_table.

What is the difference between FETCH_ASSOC and FETCH_NUM?

FETCH_ASSOC returns data as an associative array with column names as keys, while FETCH_NUM returns a numeric array with column indexes, shown by the 'Fetch Mode' column in the execution_table.

Can I fetch data as an object?

Yes, using FETCH_OBJ mode, fetch() returns each row as an object with properties matching column names.

Visual Quiz - 3 Questions

Look at the execution_table, what is the value of $row after step 3?

A {'id' => 2, 'name' => 'Bob'}

B {'id' => 1, 'name' => 'Alice'}

C false

D null

💡 Hint

Check the 'Data Returned' column for step 3 in execution_table.

At which step does fetch() return false indicating no more rows?

A Step 2

B Step 3

C Step 4

D Never

💡 Hint

Look at the 'Data Returned' column in execution_table for the step where fetch() returns false.

If we change fetch mode to PDO::FETCH_NUM, how would the data look?

A Associative array with column names as keys

B Numeric array with column indexes as keys

C Object with properties

D Boolean false

💡 Hint

Recall the difference between FETCH_ASSOC and FETCH_NUM explained in key_moments.

Concept Snapshot

PHP fetch modes control how query results are returned.
Common modes:
- FETCH_ASSOC: associative array (column names)
- FETCH_NUM: numeric array (indexes)
- FETCH_OBJ: object with properties
fetch() returns false when no rows left.

Full Transcript

This visual execution shows how PHP fetch modes work when getting data from a database. After running a query, fetch() gets one row at a time. Using FETCH_ASSOC mode, each row is an associative array with column names as keys. The variable $row changes each fetch call. When no rows remain, fetch() returns false, ending the loop. Different fetch modes change the data format: associative arrays, numeric arrays, or objects. Understanding these helps you use database results easily in your PHP code.