MySQL - Set user password with stored procedure - mysql

Question

I want to change an user's password using an stored procedure in MySQL.
Here is the creation code:
CREATE SCHEMA `try` ;
USE try;
CREATE TABLE `users` (
`username` VARCHAR(100) NOT NULL,
`password` VARCHAR(100) NOT NULL,
PRIMARY KEY(`username`));
insert into users values('Admin','pass');
create user 'usertry'#'localhost' identified by 'pass';
grant select on try.* to 'usertry'#'localhost';
grant insert on try.* to 'usertry'#'localhost';
grant update on try.* to 'usertry'#'localhost';
grant delete on try.* to 'usertry'#'localhost';
Until here, everything is good.
Then i created a stored procedure to change the table "users".
DELIMITER $$
CREATE PROCEDURE `changeusers` (
IN user VARCHAR(255),
IN pass VARCHAR(255),
IN newuser VARCHAR(255),
IN newpass VARCHAR(255),
OUT result bool)
BEGIN
if(user= Binary (Select username from users limit 1)
and pass= Binary (Select password from users limit 1))
then
delete from users where username=user;
insert into users values(newuser,newpass);
set result=true;
else
set result=false;
end if;
select result;
END $$ DELIMITER ;
When i call the stored procedure, it works well.
call changeusers('Admin','pass','Admin','new',#result);
call changeusers('Admin','pass','Admin','new',#result) 1 row(s) returned 0.141 sec / 0.000 sec
Then i tried to change the stored procedure to set the user's password same as the password in the users table.
DELIMITER $$
CREATE PROCEDURE `changeusers` (
IN user VARCHAR(255),
IN pass VARCHAR(255),
IN newuser VARCHAR(255),
IN newpass VARCHAR(255),
OUT result bool)
BEGIN
if(user= Binary (Select username from users limit 1)
and pass= Binary (Select password from users limit 1))
then
delete from users where username=user;
insert into users values(newuser,newpass);
/*The added line*/
set password for 'usertry'#'localhost' = newpass;
/*The added line*/
set result=true;
else
set result=false;
end if;
select result;
END $$ DELIMITER ;
But when i run the new script i got this:
Error Code: 1064. You have an error in your SQL syntax;
check the manual that corresponds to your MySQL server version
for the right syntax to use near
'newpass;
set result=true;
else
set result=false;'
at line 13 0.000 sec
I would apreciate any sugestions.
Thanks.
EDIT
Thanks to #Barmar. I was able to do what i want.
Here's the new stored procedure.
DELIMITER $$
CREATE PROCEDURE `changeusers` (
IN user VARCHAR(255),
IN pass VARCHAR(255),
IN newuser VARCHAR(255),
IN newpass VARCHAR(255),
OUT result bool)
BEGIN
if(user= Binary (Select username from users limit 1)
and pass= Binary (Select password from users limit 1))
then
delete from users where username=user;
insert into users values(newuser,newpass);
/*The added line*/
set #stm = CONCAT("set password for 'usertry'#'localhost' = ",newpass);
prepare stmt from #stm;
execute stmt;
deallocate prepare stmt;
/*The added line*/
set result=true;
else
set result=false;
end if;
select result;
END $$ DELIMITER ;
Thank you so much for your help.

Answer 1

I don't think SET PASSWORD allows the password to be a variable, it has to be a literal (or a call to PASSWORD() with a literal parameter. So you need to use a prepared statement:
PREPARE #stmt FROM CONCAT("SET PASSWORD FOR 'usertry'#'localhost' = '", newpass, "'");
EXECUTE #stmt;