PHP CloseCursor

When working with databases in PHP, we often use prepared statements to execute queries. In some scenarios, we may run the same prepared statement multiple times with different parameter values. In such cases, it is important to release the resources used by the statement after each execution to avoid memory leaks.

This is where the closeCursor method comes in. It's a built-in method in the PDO class that releases the database cursor associated with a prepared statement. This method should be called after we have finished fetching all the rows returned by the query execution with fetch or fetchAll methods.

Syntax

Here's the syntax of the closeCursor method:

$pdo_statement->closeCursor();

Parameters

The closeCursor method doesn't take any parameters.

Return Value

The closeCursor method returns true on success and false on failure.

Example

Here's an example that shows how to use the closeCursor method:

// Connect to the database
$dbh = new PDO('mysql:host=localhost;dbname=test', 'username', 'password');

// Prepare a statement
$stmt = $dbh->prepare('SELECT * FROM users WHERE age > :age');

// Execute the statement with the first parameter value
$stmt->execute([':age' => 18]);
$rows = $stmt->fetchAll(PDO::FETCH_ASSOC);
$stmt->closeCursor();

// Execute the statement with the second parameter value
$stmt->execute([':age' => 21]);
$rows = $stmt->fetchAll(PDO::FETCH_ASSOC);
$stmt->closeCursor();

// Close the database connection
$dbh = null;

In this example, we connect to a database and prepare a statement that retrieves all users with an age greater than a given value. We execute the same statement twice with different parameter values and call the closeCursor method after each execution to release the database cursor.

Conclusion

The closeCursor method is an essential method to release the database cursor associated with a prepared statement in PHP. Using this method correctly can help us avoid memory leaks and ensure efficient database communication.