如何在mysql的存储过程中更新临时表的行

Question

i wrote a stored procedure(getAllInitializedContact())to get data from diffrent tables.getAllInitializedContact()

CREATE DEFINER=`root`@`192.168.1.15` PROCEDURE `getAllInitializedContactNext`()
BEGIN

 DROP TEMPORARY TABLE IF EXISTS temp_users;
 CREATE TEMPORARY TABLE temp_users (
                                SELECT

                                c.id as contactId,
                                c.first_name as contactName,
                                c.email_address as contactEmailAddress,
                                sl.id as subscriberListId,
                                sl.name as subscriberListName, 
                                sl.display_name as subscriberListDisplayName,
                                sl.from_email_address,<br/>
                                sl.opt_in_msg_subject as subject,
                                sl.opt_in_msg_content as content,
                                sl.opt_in_msg_signature as signature,
                                csl.identifier
                                FROM contact c

                                          INNER JOIN contact_subscriber_list csl ON csl.contact_id=c.id
                                          INNER JOIN subscriber_list sl ON sl.id=csl.sub_list_id
                                          INNER JOIN contact_sub_list_status csls ON csls.id=csl.status_id  where csls.description='initialized');
END

but now i want to update that resultset.so i create a temporary table(temp_users) and i need to do some update to some column in temporary table(temp_users).but i cant understand how can i iterate over that and update the temp_table.i tried using while loop and dont know how it apply(while loop).can i do this using while loop? and how can i apply it?need help

regards
kosala

Answer 1

Not sure why you want to use a cursor to update the rows in your tmp table when you can simply just update them - see following example:

drop table if exists foo;
create table foo
(
foo_id int unsigned not null auto_increment primary key,
value int unsigned not null default 0
)
engine=innodb;

insert into foo (value) values (10),(20),(30);

drop procedure if exists bar;

delimiter #

create procedure bar()
begin

create temporary table tmp engine=memory select * from foo;

update tmp set value = value + 100;

select * from tmp;

drop temporary table if exists tmp;

end #

delimiter ;

call bar();

Answer 2

I was making a mistake using the update so it was not working. I though it might help someone so am sharing:

For the update to work with a temp table, data to be updated must match the column type you want to update. You can't update a string/text/varchar column with a number. This would just not work.