PDOStatement

PDOStatement is a PHP data access object representing a prepared or executed statement in the PDO extension. It is created by calling PDO::prepare (to prepare a statement for later execution) or PDO::query (which returns a statement after executing a query). The object provides methods to bind parameters, execute the statement, and fetch results in various formats, making it central to working with databases in PHP.

Parameter binding supports both named placeholders (e.g., :name) and positional placeholders (?), using bindParam or bindValue. BindParam binds a PHP variable by reference, allowing the parameter to change between executions, while BindValue binds a value at the time of binding. Execute accepts an array of input parameters to override bound values for that execution. This enables efficient repeated executions with different inputs.

Result retrieval is performed with methods such as fetch, fetchAll, and fetchColumn. fetch returns the next row in a specified fetch mode; fetchAll returns all remaining rows. fetchColumn retrieves a single column from the next row. Row counts can be obtained with rowCount, and column metadata with getColumnMeta. The fetch mode can be controlled via setFetchMode or by passing a mode to fetch, with common modes including PDO::FETCH_ASSOC, PDO::FETCH_NUM, PDO::FETCH_BOTH, and PDO::FETCH_OBJ.

Other functionalities include closeCursor, which releases the server-side resources associated with the statement, and debugDumpParams, which prints the prepared statement and bound parameters for debugging. Error information is accessible via errorCode and errorInfo, and you can retrieve driver-specific attributes with getAttribute. PDOStatement supports a variety of drivers and enables safe, efficient parameterized queries and result handling.