Connecting to databases using PHP data access extensions such as MySQLi or PDO Mocktest

Parameterized queries in MySQLi and PDO prevent SQL injection attacks by separating SQL logic from user input. They use placeholders for input values, preventing malicious SQL code injection and improving overall database security.

One of the primary advantages of using prepared statements in MySQLi and PDO is improved security and protection against SQL injection attacks. Prepared statements separate SQL logic from user input, preventing malicious SQL code injection.

The mysqli_connect() function in MySQLi extension is used to establish a connection to a MySQL database server. It takes parameters such as hostname, username, password, and database name to establish the connection.

Executing an SQL query is not a step in connecting to a MySQL database using PDO extension. The steps involve creating a PDO object, setting database credentials, handling connection errors, and optionally setting additional attributes.

The PDO::beginTransaction() method in PDO extension is used to initiate a database transaction. Transactions help maintain data integrity by ensuring that a series of SQL statements are executed as a single unit, either all succeeding or all failing.

In MySQLi extension, the mysqli_execute() method is used to execute a prepared statement with parameters. It executes the prepared statement and passes any parameters to be bound to the statement.

Database connection pooling in PHP applications is primarily used to improve scalability and performance. It allows reusing and sharing database connections among multiple clients, reducing the overhead of establishing new connections and improving overall application responsiveness.

PDO (PHP Data Objects) extension provides better support for transaction management and error handling compared to MySQLi. It offers a consistent interface for handling transactions and provides features such as automatic error handling and exception throwing.

The PDO::lastInsertId() method in PDO extension is used to retrieve the ID generated by the last INSERT statement. It is commonly used to obtain the primary key value of the last inserted row in an auto-increment column.

In PHP applications, database connections should be properly closed after use to release server resources and prevent connection leaks. Failure to close connections can lead to resource exhaustion and degrade application performance.