How Can I Retrieve the Final SQL Query String from PDO Prepared Statements?

Retrieving the Raw SQL Query String from PDO Prepared Statements

When utilizing PDO prepared statements for query execution, it can be valuable for debugging purposes to retrieve the raw SQL string that is executed. However, unlike parameterized queries, prepared statements do not combine parameters with the SQL query on the client-side.

The SQL statement and parameters are transmitted separately to the database server during the prepare() and execute() operations, respectively. Consequently, PDO lacks access to the SQL string combined with the parameters.

MySQL General Query Log:

One way to capture the final query with interpolated values is by using MySQL's general query log. This log records the final SQL statement after the execute() call. However, this technique requires enabling the general query log on the MySQL server.

PDO Prepared Statement Emulation:

Another option is to enable the PDO attribute PDO::ATTR_EMULATE_PREPARES. In this mode, PDO interpolates parameters into the SQL query before sending it during execution. However, it's crucial to note that this method is not true prepared statement execution and circumvents the benefits of using prepared queries.

PDOStatement Property Confusion:

Initial attempts at accessing the interpolated query may involve consulting the PDOStatement property $queryString. However, this property is only set during the PDOStatement constructor and not updated when parameters are interpolated into the query.

Exposure of Rewritten Query:

A potential feature improvement for PDO would be to expose the rewritten query. Even this approach would only provide the complete query when using PDO::ATTR_EMULATE_PREPARES.

Workaround:

As an alternative, you can rely on the MySQL server's general query log to view the rewritten query with interpolated parameter values after query execution.

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