unsigned int mysql_stmt_warning_count(MYSQL_STMT * stmt);
stmt- a statement handle, which was previously allocated by mysql_stmt_init().
Returns the number of warnings from the last executed statement, or zero if there are no warnings. This function was added in Connector/C 3.0.
For retrieving warning messages you should use the SQL command SHOW WARNINGS. If SQL_MODE TRADITIONAL is enabled an error instead of warning will be returned. For detailed information check the server documentation.