28. 7. 11. 17 mysql _stmt _next _result ()

This function is used when you use prepared CALL statements to execute stored procedures, which can return multiple result sets. Use a loop that calls mysql_stmt_next_result() to determine whether there are more results. If a procedure has OUT or INOUT parameters, their values will be returned as a single-row result set following any other result sets. The values will appear in the order in which they are declared in the procedure parameter list.

For information about the effect of unhandled conditions on procedure parameters, see Section 13.6.7.8, “Condition Handling and OUT or INOUT Parameters”.

mysql_stmt_next_result() returns a status to indicate whether more results exist. If mysql_stmt_next_result() returns an error, there are no more results.

Before each call to mysql_stmt_next_result(), you must call mysql_stmt_free_result() for the current result if it produced a result set (rather than just a result status).

After calling mysql_stmt_next_result() the state of the connection is as if you had called mysql_stmt_execute(). This means that you can call mysql_stmt_bind_result(), mysql_stmt_affected_rows(), and so forth.

It is also possible to test whether there are more results by calling mysql_more_results(). However, this function does not change the connection state, so if it returns true, you must still call mysql_stmt_next_result() to advance to the next result.

For an example that shows how to use mysql_stmt_next_result(), see Section 28.7.25, “C API Prepared CALL Statement Support”.