both are stored in database

mysql: show create procedure|function XXX;

stored procedure

ref https://www.programiz.com/sql/stored-procedures

use mysql’s as an example

-- mysql

create procedure ...(同下)
  stmt
;

delimiter //
create procedure NAME([[in|out|inout] PARAM type[,...]])
[...]
begin
  STMT
  ...
end //
delimiter ;

call NAME(ARG[,...]);

can use in stmt:

• start transaction commit rollback
• if, case, while, loop, repeat statement (ref https://dev.mysql.com/doc/refman/8.4/en/flow-control-statements.html)

function

• must (and only can) returns a scalar (via return RESULT; )
• pure (as in Nim)
• used anywhere expected a expression

create function NAME([[in] PARAM type[,..]]) returns TYPE
deterministic|no sql|reads sql data
...  (同procedure)