PDOException

PDOException is a specialized exception class in PHP's PDO extension. It extends RuntimeException, which is itself a subclass of the standard Exception class. PDOException represents errors that occur during database operations performed with PDO, including connection failures, SQL syntax or constraint errors, and issues during statement execution.

Errors are surfaced as exceptions only when the PDO error mode is set to PDO::ERRMODE_EXCEPTION; if the mode is ERRMODE_SILENT or ERRMODE_WARNING, errors may be silent or reported as warnings rather than thrown as exceptions.

It is common to handle PDOException with a try-catch block around database operations. The exception object provides standard methods such as getMessage() and getCode(). The error message often includes a SQLSTATE code and a driver-specific description of the problem. In addition to catching the exception, you can query error details from the PDO instance or the statement using PDO::errorInfo() and PDOStatement::errorInfo() to obtain an array of SQLSTATE, driver code, and message.

When developing, ensure that detailed error information is not exposed to end users and that such information is logged securely. Practical usage often involves wrapping critical operations in transactions and performing proper rollback in case of exceptions.

See also: PHP Data Objects (PDO), SQLSTATE, error handling in PHP.