Ok, my problem was that i have to execute query to multiple mysql server, The easy way to do that to make connection to each of those servers and send query. And i work with php. In some part of my project i need to do hundreds of query at a time and normally php don't support multiple query to database. To do that i have to change some (.h) file in server what i don't have access. I't take lots more time to execute query cos every time send a query to the remote serve the php wait for the result and then send the next query. but if i can send all the query once then it will take less time. I saw searching net for that and couldn't find a better way. Then i thought to do it by my my salfe. And i thought to make a PROCEDURE where i will send all the query with some delimiter. And i coded the below  PROCEDURE   CREATE  PROCEDURE `execute_query`(var_complexe_query LONGTEXT,var_query_delimiter VARCHAR(20))  BEGIN  SET @new_string := var_complexe_query;  SET @execute...
 Today i have to solve a problem in MySql , The problem is i have two table in openCart  1. category_description    category_id      language      name     1      1      category 1     2      1      category 2     3      1      category 3     4      1      category 4     5      1      category 5     6      1      category 6     7      1      category 7     8      1      category 8      1. product_category  produc_id category_id  1 1  1 2  1 5  2 1  2 3  2 4  3 2  3 6    The resulting data should be like that   produc_id category_name  1 category 1,category 2,category 5  2 category 1,category 3,category 4  3 category 2,category 6    I can do tha by in php by taking the category name to it's respective product id and implode them , but it will take much time and processor power cos the i have to do query every product id separately, I was searching the right query in MySql and found the function   GROUP_CONCAT()  http://dev.mysql.com/doc/refman/5.0/en/gr...