The subject of the question is not very explanatory, sorry for that.
Ya so the question follows:
I have a database structure as below where pk is primary key, id
is something which is multiple for many rows.
+------+------+---------------------+
| pk | id | value |
+------+------+---------------------+
| 99 | 1 | 2013-08-06 11:10:00 |
| 100 | 1 | 2013-08-06 11:15:00 |
| 101 | 1 | 2013-08-06 11:20:00 |
| 102 | 1 | 2013-08-06 11:25:00 |
| 103 | 2 | 2013-08-06 15:10:00 |
| 104 | 2 | 2013-08-06 15:15:00 |
| 105 | 2 | 2013-08-06 15:20:00 |
+------+------+---------------------+
What is really need to get is, value difference between first two rows (which is ordered by value) for each
group (where group is by id). So according to above structure I need
timediff(value100, value99) [ which is for id 1 group]
and timediff(value104, value103) [ which is for id 2 group]
i.e. value difference of time ordered by value for 1st two rows in each group.
One way i can think to do is by 3 self joins (or 3 sub queries) so as to find the
first two in 2 of them , and third query subtracting it. Any suggestions?
try this.. CTE is pretty powerfull!
WITH CTE AS (
SELECT
value, pk, id,
rnk = ROW_NUMBER() OVER ( PARTITION BY id order by id DESC)
, rownum = ROW_NUMBER() OVER (ORDER BY id, pk)
FROM test
)
SELECT
curr.rnk, prev.rnk, curr.rownum, prev.rownum, curr.pk, prev.pk, curr.id, prev.id, curr.value, prev.value, curr.value - prev.value
FROM CTE curr
INNER JOIN CTE prev on curr.rownum = prev.rownum -1 and curr.id = prev.id
and curr.rnk <=1
Looks a bit wierd... But you can try this way
SET #previous = 0;
SET #temp = 0;
SET #tempID = 0;
Above step may not be needed .. But just to make sure nothing goes wrong
SELECT pkid, id, diff, valtemp FROM (
SELECT IF(#previousID = id, #temp := #temp + 1, #temp := 1) occ, #previousID := id,
TIMEDIFF(`value`, #previous) diff, pk, id, `value`, #previous := `value`
FROM testtable) a WHERE occ = 2
Demo on sql fiddle
Related
I have the following table structure in a mysql database.
id | files | status
1 a.pdf,b.pdf,c.pdx 1
2 d.pdf,e.pdf.g.pdf 2
3 x.pdf,k.pdf,y.pdf 1
As you can see, the attachments are all stored on a single line.
My query is supposed to select all rows where status = 1 so i'm expecting the data in the following format.
1 1 a.pdf 1
2 1 b.pdf 1
3 1 c.pdf 1
4 3 x.pdf 1
5 3 k.pdf 1
6 3 y.pdf 1
Unfortunately, I am unsure which operator I can use to accomplish this. I'm aware SQL has pivot but i doubt even that can address my issue.
As a result, I would appreciate if I could get any help in the condition of the select query.
Regards
Try this:
SET #row_num = 0;
SELECT
(#row_num := #row_num + 1) ROW_NUM,
id,
SUBSTRING_INDEX(SUBSTRING_INDEX(files, ',', idx), ',', -1) FileName,
status
FROM
test
JOIN
(SELECT 1 idx UNION ALL SELECT 2 idx UNION ALL SELECT 3 idx UNION ALL SELECT 4 idx UNION ALL SELECT 5 idx) idxs
on idxs.idx - 2 < LENGTH(files) - LENGTH(REPLACE(files, ",", ""))
WHERE status = 1
;
Just add as many indexes as your max count of files in a string.
Note that there should be no comma fater last filename. This is magic -2 is responsible for.
Consider the following...
I have a table (ints) of integers (0-9)...
DROP TABLE IF EXISTS my_table;
CREATE TABLE my_table
(id SERIAL PRIMARY KEY
,files VARCHAR(100) NOT NULL
,status INT NOT NULL
);
INSERT INTO my_table VALUES
(1,'a.pdf,b.pdf,c.pdx',1),
(2,'d.pdf,e.pdf,g.pdf',2),
(3,'x.pdf,k.pdf,y.pdf',1);
SELECT DISTINCT id
, SUBSTRING_INDEX(SUBSTRING_INDEX(files,',',i2.i*10+i1.i+1),',',-1) file
, status
FROM my_table
, ints i1
, ints i2
WHERE status = 1
ORDER
BY id, i2.i*10+i1.i;
+----+-------+--------+
| id | file | status |
+----+-------+--------+
| 1 | a.pdf | 1 |
| 1 | b.pdf | 1 |
| 1 | c.pdx | 1 |
| 3 | x.pdf | 1 |
| 3 | k.pdf | 1 |
| 3 | y.pdf | 1 |
+----+-------+--------+
Let's consider that there are three material types such as ('COTTON', 'LEATHER', 'SILK') and I want to fetch the dress_id's which has all theses three material types. I want to rank them as well.
Can someone explain step by step on how to do this ?
I came through few examples and none of them seems to be clear to me.
The output should look something like
DRESS_ID MATERIAL LAST_UPDATED_DATE RANK
111 COTTON 2019-08-29 1
111 SILK 2019-08-30 2
111 LEATHER 2019-08-31 3
222 COTTON 2019-08-29 1
222 SILK 2019-08-30 2
222 LEATHER 2019-08-31 3
222 LEATHER 2019-09-02 4
I get an error in MYSQL work bench while executing this query.
Error Code: 1305. FUNCTION rank does not exist.
SELECT dress_id,
rank() over(PARTITION BY dress_id, material ORDER by LAST_UPDATED_DATE asc) as rank
FROM dress_types;
In earlier versions of MySQL, you can either use variables or a correlated subquery.
Because you have only a handful of materials for each dress, a correlated subquery is reasonable, particularly with the right index. The code looks like:
SELECT d.dress_id, d.material,
(SELECT COUNT(*)
FROM dress_types d2
WHERE d2.dress_id = d.dress_id AND
d2.last_updated_date <= d.last_updated_date
) as rank
FROM dress_types d;
Note that this implements the logic based on your data not the query. The corresponding query would be:
SELECT dress_id,
rank() over (PARTITION BY dress_id ORDER by LAST_UPDATED_DATE asc) as rank
FROM dress_types;
The index that you want is on dress_types(dress_id, last_updated_date).
Actually, these are the same so long as there are no duplicates (by date). The logic may be different if there are duplicates.
For previous versions of MySQL 8.0 you must use variables to simulate the ranking:
SET #rownum := 0;
SET #group_number := 0;
SELECT dress_id, material, last_updated_date, rank FROM (
SELECT #rownum := case
when #group_number = dress_id then #rownum + 1
else 1
end AS rank, dress_id, material, last_updated_date,
#group_number := dress_id
FROM dress_types
ORDER BY
dress_id,
FIELD(material, 'COTTON', 'SILK', 'LEATHER'),
last_updated_date
) t
See the demo.
Results:
| dress_id | material | last_updated_date | rank |
| -------- | -------- | ------------------- | ---- |
| 111 | COTTON | 2019-08-29 00:00:00 | 1 |
| 111 | SILK | 2019-08-30 00:00:00 | 2 |
| 111 | LEATHER | 2019-08-31 00:00:00 | 3 |
| 222 | COTTON | 2019-08-29 00:00:00 | 1 |
| 222 | SILK | 2019-08-30 00:00:00 | 2 |
| 222 | LEATHER | 2019-08-31 00:00:00 | 3 |
| 222 | LEATHER | 2019-09-02 00:00:00 | 4 |
SELECT T.*,
CASE WHEN #prev_dress_id != T.dress_id THEN #rank:=1
ELSE #rank:=#rank+1
END as rank,
#prev_dress_id := T.dress_id as set_prev_dress_id
FROM
(SELECT dress_id,material,last_updated_date
FROM dress_types T1
WHERE EXISTS (SELECT 1 FROM dress_types E1 WHERE E1.dress_id = T1.dress_ID AND E1.material = 'COTTON')
AND EXISTS (SELECT 1 FROM dress_types E2 WHERE E2.dress_id = T1.dress_ID AND E2.material = 'SILK')
AND EXISTS (SELECT 1 FROM dress_types E3 WHERE E3.dress_id = T1.dress_ID AND E3.material = 'LEATHER')
ORDER BY dress_id asc,last_updated_date asc
)T,(SELECT #prev_dress_id:=-1)V
The inner select selects dresses that have existence of all 3 materials and ordered by dress_id, last_updated_date.
The outer joins it with a prev_dress_id variable that can be set at the end of each row. The the logics in case statement to calculate rank based on #prev_dress_id != or = T.dress_id.
sqlfiddle
SELECT dress_id
, material
, LAST_UPDATED_DATE
rank() over(PARTITION BY dress_id ORDER by LAST_UPDATED_DATE asc) as rank
FROM dress_types
I have a MySQL table with timestamp column t. I need to create another integer column (groupId) which will have the same value for records with timestamp with
less then 3 sec difference. My version of MySQL has no window function support. This is the expected output in 2nd column:
+---------------------+--------+
| t | groupId|
+---------------------+--------+
| 2017-06-17 18:15:13 | 1 |
| 2017-06-17 18:15:14 | 1 |
| 2017-06-17 20:30:06 | 2 |
| 2017-06-17 20:30:07 | 2 |
| 2017-06-17 22:44:58 | 3 |
| 2017-06-17 22:44:59 | 3 |
| 2017-06-17 23:59:50 | 4 |
| 2017-06-17 23:59:51 | 4 |
I tried to use self-join and TIMESTAMPDIFF(SECOND,t1,t2) <3
but I do not know how to generate the unique groupId.
P.S.
It is guaranteed by the nature of data what there is no continues range which spans > 3 sec
You can do this using variables.
select tm
,#diff:=timestampdiff(second,#prev,tm)
,#prev:=tm
,#grp:=case when #diff<3 or #diff is null then #grp else #grp+1 end as groupID
from t
cross join (select #prev:='',#diff:=0,#grp:=1) r
order by tm
For this, I believe that you need to create a stored procedure that first sort your table by the column t (timestamp) and then goes through it grouping and assigning the groupId accordingly.... in this case you can use your own counter as groupID.
What it is important here, is how you split the time into frames of 2 seconds, you could end with different results depending of your point of reference...
This query puts every record in the same group when the previous record is just 3 seconds before:
UPDATE t
JOIN (
SELECT
t.*
, #gid := IF(TIMESTAMPDIFF(SECOND, #prev, t) > 3, #gid + 1, #gid) AS gid
, #prev := t
FROM t
, (SELECT #prev := NULL, #gid := 1) v
ORDER BY t
) sq ON t.t = sq.t
SET t.groupId = sq.gid;
see it working live in an sqlfiddle
learn more about user-defined variables here
This query will work in Oracle sql:
select *
from (
select e.*,
rank() over (partition by trunc(hiredate,'mi') order by trunc(hiredate,'mi') desc) MINu
from emp e
)
I have a table which looks like this:
+-----------------------
| id | first_name
+-----------------------
| AC0089 | John |
| AC0015 | Dan |
| AC0017 | Marry |
| AC0003 | Andy |
| AC0001 | Trent |
| AC0006 | Smith |
+-----------------------
I need a query to split the id in the range of 3 and also display the starting id of that range i.e.
+------------+----------+--------
| startrange | endrange | id
+------------+----------+--------
| 1 | 3 | AC0089
| 4 | 6 | AC0003
+------------+----------+--------
I am pretty new to SQL and trying the below query but I dont think I am near to the correct solution at all ! Here is the query:
select startrange, endrange, id from table inner join (select 1 startRange, 3 endrange union all select 4 startRange, 6 endRange) r group by r.startRange, r.endRange;
It is giving the same id every-time and I am not able to come up with any other solution. How Can I get the required output?
Try this
SET #ct := 0;
select startrange,(startrange + 2) as endrange, seq_no from
(select (c.st - (select count(*) from <table_name>)) as startrange, c.* from
(select (#ct := #ct + 1) as st, b.* from <table_name> as b) c
having startrange mod 3 = 1) as cc;
sorry for formating.
I'm not completely sure what your trying to do but if you're trying to convert a table of ID's into ranges use a case when.
CASE WHEN startrange in(1,2,3) THEN 1
ELSE NULL
END as startrange,
CASE WHEN endrange in(1,2,3) THEN 3
ELSE NULL
END as endrange,
CASE WHEN ID in(1,2,3) THEN id
WHEN ID in(4,5,6) THEN id
ELSE id
END AS ID
I have a table like the below:
CompanyID | Logged | UniqueID
A | 2014-06-24 | 8
B | 2014-06-24 | 7
A | 2014-06-16 | 6
B | 2014-06-16 | 5
A | 2014-06-08 | 4
B | 2014-06-08 | 3
A | 2014-06-01 | 2
B | 2014-06-01 | 1
I'm stuck trying to create an SQL statement that will return the quantity of rows found for each unique CompanyID, separated into 4 week periods, so something like the below:
CompanyID | Period (week) | Quantity
A | 0 | 1
B | 0 | 1
A | 1 | 1
B | 1 | 1
A | 2 | 1
B | 2 | 1
A | 3 | 1
B | 3 | 1
I have done something similar before, except by the last 7 days instead of last 4 weeks, but am not sure if this can be reworked:
select CompanyID,
case DATE_FORMAT(Logged, '%Y%m%d')
when '20140618' then '0'
when '20140619' then '1'
when '20140620' then '2'
when '20140621' then '3'
when '20140622' then '4'
when '20140623' then '5'
when '20140624' then '6'
end as period ,
count(UniqueID) as quantity from TABLE
where DATE_FORMAT(Logged, '%Y%m%d')
in (20140618,20140619,20140620,20140621,20140622,20140623,20140624) group by CompanyID,
DATE_FORMAT(Logged, '%Y%m%d')
Is there a more straightforward way to obtain the output desired above?
Maybe something like this?
SQL FIDDLE to test with
Theres the original query that doesn't use any hard coding... that is generally a really bad practice. it will have the count inflated by 1 since it starts with one and you want it to start with zero so to fix this do a select of the original query where you fix the count and then also not show the user defined variable
SELECT CompanyID, Period - 1 as Period, Quantity FROM(
SELECT
CompanyID,
if(#a = Logged, #b, #b := #b + 1) as Period,
COUNT(*) as Quantity,
#a := Logged
FROM test
JOIN (SELECT #a := '', #b := 0) as temp
GROUP BY UniqueID
ORDER BY Period
) as subQuery
ORIGINAL QUERY
SELECT
CompanyID,
if(#a = Logged, #b, #b := #b + 1) as Period,
COUNT(*) as Quantity,
#a := Logged
FROM test
JOIN (SELECT #a := '', #b := 0) as temp
GROUP BY UniqueID
ORDER BY Period