# # Demonstrate how RESIGNAL can be used to print a stack trace # # Save defaults SET @start_global_value = @@global.max_error_count; SELECT @start_global_value; SET @start_session_value = @@session.max_error_count; SELECT @start_session_value; --disable_warnings drop database if exists demo; --enable_warnings create database demo; use demo; delimiter $$; create procedure proc_1() begin declare exit handler for sqlexception resignal sqlstate '45000' set message_text='Oops in proc_1'; call proc_2(); end $$ create procedure proc_2() begin declare exit handler for sqlexception resignal sqlstate '45000' set message_text='Oops in proc_2'; call proc_3(); end $$ create procedure proc_3() begin declare exit handler for sqlexception resignal sqlstate '45000' set message_text='Oops in proc_3'; call proc_4(); end $$ create procedure proc_4() begin declare exit handler for sqlexception resignal sqlstate '45000' set message_text='Oops in proc_4'; call proc_5(); end $$ create procedure proc_5() begin declare exit handler for sqlexception resignal sqlstate '45000' set message_text='Oops in proc_5'; call proc_6(); end $$ create procedure proc_6() begin declare exit handler for sqlexception resignal sqlstate '45000' set message_text='Oops in proc_6'; call proc_7(); end $$ create procedure proc_7() begin declare exit handler for sqlexception resignal sqlstate '45000' set message_text='Oops in proc_7'; call proc_8(); end $$ create procedure proc_8() begin declare exit handler for sqlexception resignal sqlstate '45000' set message_text='Oops in proc_8'; call proc_9(); end $$ create procedure proc_9() begin declare exit handler for sqlexception resignal sqlstate '45000' set message_text='Oops in proc_9'; ## Do something that fails, to see how errors are reported drop table oops_it_is_not_here; end $$ delimiter ;$$ -- error ER_SIGNAL_EXCEPTION call proc_1(); # This is the interesting part: # the complete call stack from the origin of failure (proc_9) # to the top level caller (proc_1) is available ... show warnings; SET @@session.max_error_count = 5; SELECT @@session.max_error_count; -- error ER_SIGNAL_EXCEPTION call proc_1(); show warnings; SET @@session.max_error_count = 7; SELECT @@session.max_error_count; -- error ER_SIGNAL_EXCEPTION call proc_1(); show warnings; SET @@session.max_error_count = 9; SELECT @@session.max_error_count; -- error ER_SIGNAL_EXCEPTION call proc_1(); show warnings; drop database demo; # Restore defaults SET @@global.max_error_count = @start_global_value; SELECT @@global.max_error_count; SET @@session.max_error_count = @start_session_value; SELECT @@session.max_error_count;