PHP CRUD Operations

CRUD stands for create, read, update, and delete, the four things you can do with information. It is like a library where you can add a book, find one, fix its label, or take it away.

In this page:

Create Operation (Insert)
Read Operation (Select)
Update Operation (Update)
Delete Operation (Delete)
Complete CRUD Flow

Syntax

php

INSERT INTO table_name (column1, column2) VALUES (value1, value2);   // Create
SELECT column1 FROM table_name WHERE condition;                       // Read
UPDATE table_name SET column1 = value WHERE condition;                // Update
DELETE FROM table_name WHERE condition;                               // Delete

Create Operation (Insert)

CRUD stands for Create, Read, Update, Delete — the four fundamental operations any application performs on stored data, and they map directly onto SQL's INSERT, SELECT, UPDATE, and DELETE statements.

Example: Create Operation (Insert)

php

<?php
// CRUD: Create, Read, Update, Delete -- maps to INSERT, SELECT, UPDATE, DELETE
$db = new SQLite3(':memory:');
$db->exec("CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT)");
echo "Table ready for CRUD operations";
?>

Read Operation (Select)

Create operations use an INSERT statement, typically through a prepared statement with bound parameters, to add a new row — like a new user record — to a table.

Example: Read Operation (Select)

php

<?php
// Create a new `SQLite3` instance with ':memory:', stored in `$db`
$db = new SQLite3(':memory:');
$db->exec("CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT)");
// Declare `$stmt`, set to `$db->prepare("INSERT INTO users (name) VALUES (:name)")`
$stmt = $db->prepare("INSERT INTO users (name) VALUES (:name)");
$stmt->bindValue(':name', 'Alice', SQLITE3_TEXT);
$stmt->execute();
// Print "New row inserted" to the output
echo "New row inserted";
?>

Update Operation (Update)

Read operations use SELECT statements to fetch existing data, ranging from a single record by ID to a filtered, sorted list of many records depending on the query's WHERE and ORDER BY clauses.

Example: Update Operation (Update)

php

<?php
// Create a new `SQLite3` instance with ':memory:', stored in `$db`
$db = new SQLite3(':memory:');
$db->exec("CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT)");
$db->exec("INSERT INTO users (name) VALUES ('Alice')");
// Declare `$result`, set to `$db->query("SELECT * FROM users WHERE id = 1")`
$result = $db->query("SELECT * FROM users WHERE id = 1");
// Print a human-readable dump of `$result->fetchArray()`
print_r($result->fetchArray());
?>

Delete Operation (Delete)

Update operations use an UPDATE statement with a WHERE clause identifying exactly which row(s) to change — forgetting the WHERE clause is a classic, dangerous mistake that updates every row in the table.

Example: Delete Operation (Delete)

php

<?php
// Create a new `SQLite3` instance with ':memory:', stored in `$db`
$db = new SQLite3(':memory:');
$db->exec("CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT)");
$db->exec("INSERT INTO users (name) VALUES ('Alice')");
$db->exec("UPDATE users SET name = 'Alicia' WHERE id = 1");
// Print "Row updated" to the output
echo "Row updated";
?>

Complete CRUD Flow

Delete operations use a DELETE statement, and like UPDATE, an accidentally omitted WHERE clause will remove every row — many teams build a 'soft delete' pattern (marking a row inactive instead of removing it) to guard against this.

Example: Complete CRUD Flow

php

<?php
// Create a new `SQLite3` instance with ':memory:', stored in `$db`
$db = new SQLite3(':memory:');
$db->exec("CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT)");
$db->exec("INSERT INTO users (name) VALUES ('Alice')");
$db->exec("DELETE FROM users WHERE id = 1");
// Print "Row deleted" to the output
echo "Row deleted";
?>

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