CRUD stands for Create, Read, Update, and Delete. These operations allow complete control over database data.
1.) Create (Insert Data)
- Use an HTML form to accept user input and an SQL INSERT statement to store the data.
Example: Insert Data
<form method="POST" action="">
Name: <input type="text" name="name" required>
Email: <input type="email" name="email" required>
<button type="submit" name="submit">Submit</button>
</form>
<?php
if (isset($_POST['submit'])) {
$name = $_POST['name'];
$email = $_POST['email'];
$sql = "INSERT INTO users (name, email) VALUES ('$name', '$email')";
if ($conn->query($sql) === TRUE) {
echo "New record created successfully!";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
}
?>
2.) Read (Display Data)
- Retrieve and display data using an SQL SELECT statement.
Example: Display Data
<?php
$sql = "SELECT id, name, email FROM users";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
while ($row = $result->fetch_assoc()) {
echo "ID: " . $row["id"] . " - Name: " . $row["name"] . " - Email: " . $row["email"] . "<br>";
}
} else {
echo "No records found.";
}
?>
3.) Update (Modify Data)
- Update existing data using an SQL UPDATE statement.
Example: Update Data
<form method="POST" action="">
User ID: <input type="number" name="id" required>
New Name: <input type="text" name="new_name" required>
<button type="submit" name="update">Update</button>
</form>
<?php
if (isset($_POST['update'])) {
$id = $_POST['id'];
$new_name = $_POST['new_name'];
$sql = "UPDATE users SET name='$new_name' WHERE id=$id";
if ($conn->query($sql) === TRUE) {
echo "Record updated successfully!";
} else {
echo "Error: " . $conn->error;
}
}
?>
4.) Delete (Remove Data)
- Delete data using an SQL DELETE statement.
Example: Delete Data
<form method="POST" action="">
User ID to Delete: <input type="number" name="id" required>
<button type="submit" name="delete">Delete</button>
</form>
<?php
if (isset($_POST['delete'])) {
$id = $_POST['id'];
$sql = "DELETE FROM users WHERE id=$id";
if ($conn->query($sql) === TRUE) {
echo "Record deleted successfully!";
} else {
echo "Error: " . $conn->error;
}
}
?>