I have table of orders. Each customer (identified by the email field) has his own orders. I need to give a different sequence of order numbers for each customer. Here is example:
----------------------------
| email | number |
----------------------------
| test#com.com | 1 |
----------------------------
| example#com.com | 1 |
----------------------------
| test#com.com | 2 |
----------------------------
| test#com.com | 3 |
----------------------------
| client#aaa.com | 1 |
----------------------------
| example#com.com | 2 |
----------------------------
Is possible to do that in a simple way with mysql?
If you want update data in this table after an insert, first of all you need a primary key, a simple auto-increment column does the job.
After that you can try to elaborate various script to fill the number column, but as you can see from other answer, they are not so "simple way".
I suggest to assign the order number in the insert statement, obtaining the order number with this "simpler" query.
select coalesce(max(`number`), 0)+1
from orders
where email='test1#test.com'
If you want do everything in a single insert (better for performance and to avoid concurrency problems)
insert into orders (email, `number`, other_field)
select email, coalesce(max(`number`), 0) + 1 as number, 'note...' as other_field
from orders where email = 'test1#test.com';
To be more confident about not assign at the same customer two orders with the same number, I strongly suggest to add an unique constraint to the columns (email,number)
create a column order_number
SELECT #i:=1000;
UPDATE yourTable SET order_number = #i:=#i+1;
This will keep incrementing the column value in order_number column and will start right after 1000, you can change the value or even you can even use the primary key as the order number since it is unique all the time
I think one more need column for this type of out put.
Example
+------+------+
| i | j |
+------+------+
| 1 | 11 |
| 1 | 12 |
| 1 | 13 |
| 2 | 21 |
| 2 | 22 |
| 2 | 23 |
| 3 | 31 |
| 3 | 32 |
| 3 | 33 |
| 4 | 14 |
+------+------+
You can get this result:
+------+------+------------+
| i | j | row_number |
+------+------+------------+
| 1 | 11 | 1 |
| 1 | 12 | 2 |
| 1 | 13 | 3 |
| 2 | 21 | 1 |
| 2 | 22 | 2 |
| 2 | 23 | 3 |
| 3 | 31 | 1 |
| 3 | 32 | 2 |
| 3 | 33 | 3 |
| 4 | 14 | 1 |
+------+------+------------+
By running this query, which doesn't need any variable defined:
SELECT a.i, a.j, count(*) as row_number FROM test a
JOIN test b ON a.i = b.i AND a.j >= b.j
GROUP BY a.i, a.j
Hope that helps!
You can add number using SELECT statement without adding any columns in table orders.
try this:
SELECT email,
(CASE email
WHEN #email
THEN #rownumber := #rownumber + 1
ELSE #rownumber := 1 AND #email:= email END) as number
FROM orders
JOIN (SELECT #rownumber:=0, #email:='') AS t
Related
Hello I would like to make event for my application that works by insert new 3 record for 1 userID every midnight so the quantity of rows must have
n x 3 n is userIDs
+---------+-----------+-------+------------+------+----------+-------------+-------+
| userID | userNAME | chaID | chaNAME | goal | gender | row_number | dummy |
+---------+-----------+-------+------------+------+----------+-------------+-------+
| 1 | Nanyang | 1 | blahblah | 1 | 2 | 1 | 1 |
| 1 | Nanyang | 21 | something | 1 | 2 | 2 | 1 |
| 1 | Nanyang | 2 | anything | 1 | 2 | 3 | 1 |
| 2 | Julie | 3 | x | 2 | 1 | 1 | 2 |
| 2 | Julie | 12 | y | 2 | 1 | 2 | 2 |
| 2 | Julie | 23 | z | 2 | 1 | 3 | 2 |
| 3 | Kingkong | 4 | a | 1 | 2 | 1 | 3 |
| 3 | Kingkong | 5 | b | 1 | 2 | 2 | 3 |
| 3 | Kingkong | 6 | c | 1 | 2 | 3 | 3 |
+---------+-----------+-------+------------+------+----------+-------------+-------+
the row_number will be looped until they're <= 3
from my written ..
set #num := 0, #type := ‘';
CREATE TABLE random
as
(
SELECT
*
FROM (
select userID,userNAME, chaID, chaNAME,goal,gender,
#num := if(#type = userID, #num +1,1) as row_number,
#type := userID as dummy
from userchar
order by userID
) as x where x.row_number <= 3)
Anyway I used to try to create table with Select the first/least/max row per group in SQL
and it works very well and get the result like i shown. then I need to insert into in event instead of create table so i got this code below.. because I can't use SET #parameterfor insert
INSERT INTO random(userID, userNAME, chaID, chaNAME, goal, gender,row_number,dummy,status)
select *
from (select userID, userNAME, chaID, chaNAME, goal, gender,
(#num := if(#type = userID, #num +1,1)
) as row_number,
userID as dummy,
#stat as status
from hb_usercha u cross join
(select #type = '', #num := 0, #stat := '') params
order by userID,rand()
)
where row_number <= 3;
and this is a result what I got
+---------+-----------+-------+------------+------+----------+-------------+-------+
| userID | userNAME | chaID | chaNAME | goal | gender | row_number | dummy |
+---------+-----------+-------+------------+------+----------+-------------+-------+
| 1 | Nanyang | 1 | blahblah | 1 | 2 | 1 | 1 |
| 1 | Nanyang | 21 | something | 1 | 2 | 1 | 1 |
| 1 | Nanyang | 2 | anything | 1 | 2 | 1 | 1 |
| 1 | Nanyang | 3 | s | 2 | 1 | 1 | 1 |
| 1 | Nanyang | 12 | o | 2 | 1 | 1 | 1 |
| 1 | Nanyang | 23 | m | 2 | 1 | 1 | 1 |
| 1 | Nanyang | 4 | e | 1 | 2 | 1 | 1 |
| 2 | Julie | 5 | xoxo | 1 | 2 | 1 | 2 |
| 2 | Julie | 6 | xxx | 1 | 2 | 1 | 2 |
+---------+-----------+-------+------------+------+----------+-------------+-------+
.
.
.
.
It seems row_number loop isn't working
And I have no idea what's happening
Both code are same just changed parameters path
So It would be very good if someone can explain to me
Thank you so much
Assuming you want to do it for all users exists in user_char table.
Using Union all to get 3 records of each user and store the result in temporary table.
DELIMITER $$
CREATE EVENT `event_run_midnight` ON SCHEDULE EVERY 24 HOUR STARTS '2016-02-09 00:00:00' ON COMPLETION NOT PRESERVE ENABLE DO
BEGIN
drop temporary table if exists temp_users_1;
create Temporary table temp_users_1
select users.*,#row_num:=#row_num+1 as row_num,userID as dummy
from(
select * from user_char
union all
select * from user_char
union all
select * from user_char
) as users,(select #row_num:=0) as row_number
order by UserID;
/*
Copy temp table data to other temp table as MySQL
not allows to use same temp table in single query.
*/
drop temporary table if exists temp_users_2;
create Temporary table temp_users_2
select * from temp_users_1;
-- final query which returns desired output :
INSERT INTO random(userID, userNAME, chaID, chaNAME, goal, gender,row_number,dummy)
Select usr.userID,
usr.userNAME,
usr.chaID,
usr.chaNAME,
usr.goal,
usr.gender,
usr.row_num-usr_grp.min_row_num+1 as row_number,
usr.userID as dummy
from temp_users_1 usr
inner join (
Select userID,
min(row_num) as min_row_num
from temp_users_2 group by userID
) usr_grp on usr.UserID=usr_grp.userID
where usr.row_num-usr_grp.min_row_num+1 <=3; -- Condition to show only 3 records of each users.
END$$
DELIMITER ;
Updates:
1- Added Event Creation.
2- Assuming you are inserting repetitive user records into table name random.
3- This Event will execute daily at 12:00 AM.
Note:
1- You may have to change the table names if tables names are different as in answer.
2- Make sure that you have enabled MySQL Event scheduler in Configuration file otherwise event will not run automatically.
Here is the link which help you enabling MySQL event scheduler if not enabled:
http://geeksterminal.com/enable-mysql-event-scheduler-status/1711/
Sorry for the kind of meaningless title, but I couldn't come up with a more fitting one.
I have a MySQL table, which looks like this:
SELECT * FROM `table`
+----+-----------+----------+-------+
| id | dimension | order_by | value |
+----+-----------+----------+-------+
| 1 | 1 | 1 | 1st |
| 2 | 1 | 100 | 3rd |
| 3 | 2 | 300 | 5th |
| 4 | 3 | 999 | 6th |
| 5 | 1 | 2 | 2nd |
| 6 | 2 | 1 | 4th |
+----+-----------+----------+-------+
I am listing all entries ordered by dimension (first) and order_by (second), which looks like this:
SELECT * FROM `table` ORDER BY `dimension`, `order_by`
+----+-----------+----------+-------+
| id | dimension | order_by | value |
+----+-----------+----------+-------+
| 1 | 1 | 1 | 1st |
| 5 | 1 | 2 | 2nd |
| 2 | 1 | 100 | 3rd |
| 6 | 2 | 1 | 4th |
| 3 | 2 | 300 | 5th |
| 4 | 3 | 999 | 6th |
+----+-----------+----------+-------+
Now I'd like to write a function, that rearranges the order_by, if possible with just one update query, to make it look that way:
SELECT * FROM `table` ORDER BY `dimension`, `order_by`
+----+-----------+----------+-------+
| id | dimension | order_by | value |
+----+-----------+----------+-------+
| 1 | 1 | 1 | 1st |
| 5 | 1 | 2 | 2nd |
| 2 | 1 | 3 | 3rd |
| 6 | 2 | 1 | 4th |
| 3 | 2 | 2 | 5th |
| 4 | 3 | 1 | 6th |
+----+-----------+----------+-------+
What I got so far (which, unfortunately, doesn't start recounting for each dimension):
UPDATE `table` AS `l`
JOIN (SELECT #i=1 FROM `table`) AS `i`
SET `order_by` = #i:=i
Now, my question would be: Is it possible to do it with just one UPDATE query?
You have to introduce another variable holding the value of the previous row.
UPDATE Table1 t
INNER JOIN (
SELECT
id, /*your primary key I assume*/
#new_ob:=if(#prev != dimension, 1, #new_ob + 1) as new_ob,
#prev := dimension /*In this line, the value of the current row is assigned. In the previous line, the variable still holds the value of the previous row*/
FROM
Table1
, (SELECT #prev := null, #new_ob := 0) var_init_subquery
ORDER BY dimension, order_by
) st ON t.id = st.id
SET t.order_by = st.new_ob;
see it working live in an sqlfiddle
I have two tables containing fields as below.
Table 1
| SetID | InQty | Day |
| 1 | 10 | 1 |
| 2 | 10 | 2 |
| 3 | 10 | 3 |
Table 2
| SetID | OtQty | Day |
| 1 | 1 | 5 |
| 1 | 2 | 6 |
| 1 | 3 | 7 |
SetID in table 2 is linked with SetId in table 1. Day is placed in place of date, just for convenience only. Expected Output,
| Day | InQty | OtQty |
| 1 | 10 | |
| 5 | | 1 |
| 6 | | 2 |
| 7 | | 3 |
Blank Space can be filled with NULL or Zero.
It appears you are querying ONLY for set ID = 1 otherwise, I would expect to see in/out values for Set 2 and 3. You should be able to get with a simple UNION
select t1.Day, t1.InQty, 0 OutQty
from Table1 t1
where SetID = 1
order by t1.Day
union select t2.Day, 0, t2.OtQty
from Table2 t2
where SetID = 1
Now, if you want totals spanning different "setID"s and keeping them differentiated from each other, just add the setID as a column and also add to the group by clause as well.
I have events flowing into a MySQL database and I need to group and sum the events to transactions and store away into another table. The data looks like:
+----+---------+------+-------+
| id | transid | code | value |
+----+---------+------+-------+
| 1 | 1 | b | 12 |
| 2 | 1 | i | 23 |
| 3 | 2 | b | 34 |
| 4 | 1 | e | 45 |
| 5 | 3 | b | 56 |
| 6 | 2 | i | 67 |
| 7 | 2 | e | 78 |
| 8 | 3 | i | 89 |
| 9 | 3 | i | 90 |
+----+---------+------+-------+
The events arrive in batches and I would like to create the transaction by summing up the values for each transid, like:
select transid, sum(value) from eventtable group by transid;
but only after all the events for that transid have arrived. That is determined by the event with the code e (b for the beginning, e for the end and i for varying amount of intermediates). Being a novice in SQL, how could I implement the requirement for the existance of the end code before the summing?
Perhaps with having:
select transid, sum(value)
from eventtable
group by transid
having max(case code when 'e' then 1 end)=1;
select transid, sum(value) from eventtable
group by transid
HAVING COUNT(*) = 3
you should count the records in the group. So when there is (b)egin, (i)?? don't know what it is and (e)nd this group is not filtered out.
I have a query to get the top 'n' users who commented on a specific keyword,
SELECT `user` , COUNT( * ) AS magnitude
FROM `results`
WHERE `keyword` = "economy"
GROUP BY `user`
ORDER BY magnitude DESC
LIMIT 5
I have approx 6000 keywords, and would like to run this query to get me the top 'n' users for each and every keyword we have data for. Assistance appreciated.
Since you haven't given the schema for results, I'll assume it's this or very similar (maybe extra columns):
create table results (
id int primary key,
user int,
foreign key (user) references <some_other_table>(id),
keyword varchar(<30>)
);
Step 1: aggregate by keyword/user as in your example query, but for all keywords:
create view user_keyword as (
select
keyword,
user,
count(*) as magnitude
from results
group by keyword, user
);
Step 2: rank each user within each keyword group (note the use of the subquery to rank the rows):
create view keyword_user_ranked as (
select
keyword,
user,
magnitude,
(select count(*)
from user_keyword
where l.keyword = keyword and magnitude >= l.magnitude
) as rank
from
user_keyword l
);
Step 3: select only the rows where the rank is less than some number:
select *
from keyword_user_ranked
where rank <= 3;
Example:
Base data used:
mysql> select * from results;
+----+------+---------+
| id | user | keyword |
+----+------+---------+
| 1 | 1 | mysql |
| 2 | 1 | mysql |
| 3 | 2 | mysql |
| 4 | 1 | query |
| 5 | 2 | query |
| 6 | 2 | query |
| 7 | 2 | query |
| 8 | 1 | table |
| 9 | 2 | table |
| 10 | 1 | table |
| 11 | 3 | table |
| 12 | 3 | mysql |
| 13 | 3 | query |
| 14 | 2 | mysql |
| 15 | 1 | mysql |
| 16 | 1 | mysql |
| 17 | 3 | query |
| 18 | 4 | mysql |
| 19 | 4 | mysql |
| 20 | 5 | mysql |
+----+------+---------+
Grouped by keyword and user:
mysql> select * from user_keyword order by keyword, magnitude desc;
+---------+------+-----------+
| keyword | user | magnitude |
+---------+------+-----------+
| mysql | 1 | 4 |
| mysql | 2 | 2 |
| mysql | 4 | 2 |
| mysql | 3 | 1 |
| mysql | 5 | 1 |
| query | 2 | 3 |
| query | 3 | 2 |
| query | 1 | 1 |
| table | 1 | 2 |
| table | 2 | 1 |
| table | 3 | 1 |
+---------+------+-----------+
Users ranked within keywords:
mysql> select * from keyword_user_ranked order by keyword, rank asc;
+---------+------+-----------+------+
| keyword | user | magnitude | rank |
+---------+------+-----------+------+
| mysql | 1 | 4 | 1 |
| mysql | 2 | 2 | 3 |
| mysql | 4 | 2 | 3 |
| mysql | 3 | 1 | 5 |
| mysql | 5 | 1 | 5 |
| query | 2 | 3 | 1 |
| query | 3 | 2 | 2 |
| query | 1 | 1 | 3 |
| table | 1 | 2 | 1 |
| table | 3 | 1 | 3 |
| table | 2 | 1 | 3 |
+---------+------+-----------+------+
Only top 2 from each keyword:
mysql> select * from keyword_user_ranked where rank <= 2 order by keyword, rank asc;
+---------+------+-----------+------+
| keyword | user | magnitude | rank |
+---------+------+-----------+------+
| mysql | 1 | 4 | 1 |
| query | 2 | 3 | 1 |
| query | 3 | 2 | 2 |
| table | 1 | 2 | 1 |
+---------+------+-----------+------+
Note that when there are ties -- see users 2 and 4 for keyword "mysql" in the examples -- all parties in the tie get the "last" rank, i.e. if the 2nd and 3rd are tied, both are assigned rank 3.
Performance: adding an index to the keyword and user columns will help. I have a table being queried in a similar way with 4000 and 1300 distinct values for the two columns (in a 600000-row table). You can add the index like this:
alter table results add index keyword_user (keyword, user);
In my case, query time dropped from about 6 seconds to about 2 seconds.
You can use a pattern like this (from Within-group quotas (Top N per group)):
SELECT tmp.ID, tmp.entrydate
FROM (
SELECT
ID, entrydate,
IF( #prev <> ID, #rownum := 1, #rownum := #rownum+1 ) AS rank,
#prev := ID
FROM test t
JOIN (SELECT #rownum := NULL, #prev := 0) AS r
ORDER BY t.ID
) AS tmp
WHERE tmp.rank <= 2
ORDER BY ID, entrydate;
+------+------------+
| ID | entrydate |
+------+------------+
| 1 | 2007-05-01 |
| 1 | 2007-05-02 |
| 2 | 2007-06-03 |
| 2 | 2007-06-04 |
| 3 | 2007-07-01 |
| 3 | 2007-07-02 |
+------+------------+