MySQL Prepared Statements OUT Parameters Guide

In MySQL, the Prepare Statement is used to pre-compile SQL statements, which can improve query performance and prevent SQL injection attacks. However, MySQL’s Prepare Statement does not directly support out parameters.

If you need to use outbound parameters in a prepared statement, you can achieve this by using user variables. These variables can be set in the prepared statement and used in subsequent queries.

Here is an example of a MySQL prepared statement showing how to use user variables to simulate output parameters.

SET @out_param := NULL;

PREPARE stmt FROM 'SELECT column_name INTO @out_param FROM table_name WHERE condition';
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

SELECT @out_param AS out_param;

In the example above, @out_param is a user variable used to store the value of the output parameter. Start by initializing this variable as NULL. Next, execute the query using a prepared statement and store the results in @out_param. Finally, output the value of @out_param as the output parameter using a regular SELECT statement.

Please note that using user variables to simulate output parameters may have some limitations and potential performance issues. If possible, it is recommended to use stored procedures to handle cases where output parameters are needed.