I have an Azure SQL Database table which is filled by importing XML-files.
The order of the files is random so I could get something like this:
ID | Name | DateFile | IsCorrection | Period | Other data
1 | Mr. A | March, 1 | false | 3 | Foo
20 | Mr. A | March, 1 | true | 2 | Foo
13 | Mr. A | Apr, 3 | true | 2 | Foo
4 | Mr. B | Feb, 1 | false | 2 | Foo
This table is joined with another table, which is also joined with a 3rd table.
I need to get the join of these 3 tables for the person with the newest data, based on Period, DateFile and Correction.
In my above example, Id=1 is the original data for Period 3, I need this record.
But in the same file was also a correction for Period 2 (Id=20) and in the file of April, the data was corrected again (Id=13).
So for Period 3, I need Id=1, for Period 2 I need Id=13 because it has the last corrected data and I need Id=4 because it is another person.
I would like to do this in a view, but using a stored procedure would not be a problem.
I have no idea how to solve this. Any pointers will be much appreciated.
EDIT:
My datamodel is of course much more complex than this sample. DateFile and Period are DateTime types in the table. Actually Period is two DateTime columns: StartPeriod and EndPeriod.
Well looking at your data I believe we can disregard the IsCorrection column and just pick the latest column for each user/period.
Lets start by ordering the rows placing the latest on top :
SELECT ROW_NUMBER() OVER (PARTITION BY Period, Name ORDER by DateFile DESC), *
And from this result you select all with row number 1:
;with numberedRows as (
SELECT ROW_NUMBER() OVER (PARTITION BY Period, Name ORDER by DateFile DESC) as rowIndex, *
)
select * from numberedRows where rowIndex=1
The PARTITION BY tells ROW_NUMBER() to reset the counter whenever it encounters change in the columns Period and Name. The ORDER BY tells the ROW_NUMBER() that we want th newest row to be number 1 and then older posts afterwards. We only need the latest row.
The WITH declares a "common table expression" which is a kind of subquery or temporary table.
Not knowing your exact data, I might recommend you something wrong, but you should be able to join your with last query with other tables to get your desired result.
Something like:
;with numberedRows as (
SELECT ROW_NUMBER() OVER (PARTITION BY Period, Name ORDER by DateFile DESC) as rowIndex, *
)
select * from numberedRows a
JOIN periods b on b.empId = a.Id
JOIN msg c on b.msgId = c.Id
where a.rowIndex=1
Related
I have two tables:
Table0:
| ID | TYPE | TIME | SITE |
|----|------|-------|------|
| aa | 1 | 12-18 | 100 |
| aa | 1 | 12-10 | 101 |
| bb | 2 | 12-10 | 102 |
| cc | 1 | 12-09 | 100 |
| cc | 2 | 12-12 | 103 |
| cc | 2 | 12-01 | 109 |
| cc | 1 | 12-07 | 101 |
| dd | 1 | 12-08 | 100 |
and
Table1:
| ID |
|----|
| aa |
| cc |
| cc |
| dd |
| dd |
I'm trying to output results where:
ID must exist in both tables.
TYPE must be the maximum for each ID.
TIME must be the minimum value for the maximum TYPE for each ID.
SITE should be the value from the same row as the minimum TIME value.
Given my sample data, my results should look like this:
| ID | TYPE | TIME | SITE |
|----|------|-------|------|
| aa | 1 | 12-10 | 101 |
| cc | 2 | 12-01 | 109 |
| dd | 1 | 12-08 | 100 |
I've tried these statements:
INSERT INTO "NuTable"
SELECT DISTINCT(QTS."ID"), "SITE",
CASE WHEN MAS.MAB=1 THEN 'B'
WHEN MAS.MAB=2 THEN 'F'
ELSE NULL END,
"TIME"
FROM (SELECT DISTINCT("ID") FROM TABLE1) AS QTS,
TABLE0 AS MA,
(SELECT "ID", MAX("TYPE") AS MASTY, MIN("TIME") AS MASTM
FROM TABLE0
GROUP BY "ID") AS MAS,
WHERE QTS."ID" = MA."ID"
AND QTS."ID" = MAS."ID"
AND MSD.MASTY =MA."TYPE"
...which generates a syntax error
INSERT INTO "NuTable"
SELECT DISTINCT(QTS."ID"), "SITE",
CASE WHEN MAS.MAB=1 THEN 'B'
WHEN MAS.MAB=2 THEN 'F'
ELSE NULL END,
"TIME"
FROM (SELECT DISTINCT("ID") FROM TABLE1) AS QTS,
TABLE0 AS MA,
(SELECT "ID", MAX("TYPE") AS MAB
FROM TABLE0
GROUP BY "ID") AS MAS,
((SELECT "ID", MIN("TIME") AS MACTM, MIN("TYPE") AS MACTY
FROM TABLE0
WHERE "TYPE" = 1
GROUP BY "ID")
UNION
(SELECT "ID", MIN("TIME"), MAX("TYPE")
FROM TABLE0
WHERE "TYPE" = 2
GROUP BY "ID")) AS MACU
WHERE QTS."ID" = MA."ID"
AND QTS."ID" = MAS."ID"
AND MACU."ID" = QTS."ID"
AND MA."TIME" = MACU.MACTM
AND MA."TYPE" = MACU.MACTB
... which is getting the wrong results.
Answering your direct question "how to avoid...":
You get this error when you specify a column in a SELECT area of a statement that isn't present in the GROUP BY section and isn't part of an aggregating function like MAX, MIN, AVG
in your data, I cannot say
SELECT
ID, site, min(time)
FROM
table
GROUP BY
id
I didn't say what to do with SITE; it's either a key of the group (in which case I'll get every unique combination of ID,site and the min time in each) or it should be aggregated (eg max site per ID)
These are ok:
SELECT
ID, max(site), min(time)
FROM
table
GROUP BY
id
SELECT
ID, site, min(time)
FROM
table
GROUP BY
id,site
I cannot simply not specify what to do with it- what should the database return in such a case? (If you're still struggling, tell me in the comments what you think the db should do, and I'll better understand your thinking so I can tell you why it can't do that ). The programmer of the database cannot make this decision for you; you must make it
Usually people ask this when they want to identify:
The min time per ID, and get all the other row data as well. eg "What is the full earliest record data for each id?"
In this case you have to write a query that identifies the min time per id and then join that subquery back to the main data table on id=id and time=mintime. The db runs the subquery, builds a list of min time per id, then that effectively becomes a filter of the main data table
SELECT * FROM
(
SELECT
ID, min(time) as mintime
FROM
table
GROUP BY
id
) findmin
INNER JOIN table t ON t.id = findmin.id and t.time = findmin.mintime
What you cannot do is start putting the other data you want into the query that does the grouping, because you either have to group by the columns you add in (makes the group more fine grained, not what you want) or you have to aggregate them (and then it doesn't necessarily come from the same row as other aggregated columns - min time is from row 1, min site is from row 3 - not what you want)
Looking at your actual problem:
The ID value must exist in two tables.
The Type value must be largest group by id.
The Time value must be smallest in the largest type group.
Leaving out a solution that involves having or analytics for now, so you can get to grips with the theory here:
You need to find the max type group by id, and then join it back to the table to get the other relevant data also (time is needed) for that id/maxtype and then on this new filtered data set you need the id and min time
SELECT t.id,min(t.time) FROM
(
SELECT
ID, max(type) as maxtype
FROM
table
GROUP BY
id
) findmax
INNER JOIN table t ON t.id = findmax.id and t.type = findmax.maxtype
GROUP BY t.id
If you can't see why, let me know
demo:db<>fiddle
SELECT DISTINCT ON (t0.id)
t0.id,
type,
time,
first_value(site) OVER (PARTITION BY t0.id ORDER BY time) as site
FROM table0 t0
JOIN table1 t1 ON t0.id = t1.id
ORDER BY t0.id, type DESC, time
ID must exist in both tables
This can be achieved by joining both tables against their ids. The result of inner joins are rows that exist in both tables.
SITE should be the value from the same row as the minimum TIME value.
This is the same as "Give me the first value of each group ofids ordered bytime". This can be done by using the first_value() window function. Window functions can group your data set (PARTITION BY). So you are getting groups of ids which can be ordered separately. first_value() gives the first value of these ordered groups.
TYPE must be the maximum for each ID.
To get the maximum type per id you'll first have to ORDER BY id, type DESC. You are getting the maximum type as first row per id...
TIME must be the minimum value for the maximum TYPE for each ID.
... Then you can order this result by time additionally to assure this condition.
Now you have an ordered data set: For each id, the row with the maximum type and its minimum time is the first one.
DISTINCT ON gives you exactly the first row of each group. In this case the group you defined is (id). The result is your expected one.
I would write this using distinct on and in/exists:
select distinct on (t0.id) t0.*
from table0 t0
where exists (select 1 from table1 t1 where t1.id = t0.id)
order by t0.id, type desc, time asc;
I am trying to create a report that pulls the date from a previous row, does some calculation and then displays the answer on the row below that row. The column in question is "Time Spent".
E.g. I have 3 rows.
+=====+===============+============+====+
|name | DatCompleted | Time Spent | idx|
+=====+===============+============+====+
| A | 1/1/17 | NULL | 0 |
+-----+---------------+------------+----+
| B | 11/1/17 | 10 days | 1 |
+-----+---------------+------------+----+
| C | 20/1/17 | 9 days | 2 |
+=====+===============+============+====+
Time Spent C = DatCompleted of C - DateCompleted of B
Apart from using a crazy loop and using row x row instead of set I can't see how I would complete this. Has anyone ever used this logic before in SQL? If how did you go about this?
Thanks in advance!
Most databases support the ANSI standard LAG() function. Date functions differ depending on the database, but something like this:
select t.*,
(DateCompleted - lag(DateCompleted) over (order by DateCompleted)) as TimeSpent
from t;
In SQL Server, you would use datediff():
select t.*,
datediff(day,
lag(DateCompleted) over (order by DateCompleted),
DateCompleted
) as TimeSpent
from t;
You can do this by using ROW number syntax is
ROW_NUMBER ( ) OVER ( [ PARTITION BY value_expression , ... [ n ] ] order_by_clause)
For reference you can use ROW_NUMBER
You have an index already (similar to rownumber above). Join to itself.
Select table1.*
,TimeSpent=DateDiff("d",table1.DateCompleted,copy.DateCompleted)
from table1
join table1 copy on table.idx=copy.idx-1
i have a table like this
userid | points | position
1 | 100 | NULL
2 | 89 | NULL
3 | 107 | NULL
i need a query for update the position column ordering by points desc, example result:
userid | points | position
1 | 100 | 2
2 | 89 | 3
3 | 107 | 1
I would not use physical columns that depend on values in other rows, otherwise you have to update the entire table every time one row changes. Use a view or other mechanism to calculate the position on the fly.
The query to calculate "position" would look something like:
SELECT
userid,
points,
RANK() OVER (ORDER BY points DESC) AS position
However, if you have to make it an UPDATE then you could use something like
UPDATE a
SET a.position = b.position
FROM {table_name} a
INNER JOIN
(
SELECT
userid,
RANK() OVER (ORDER BY points DESC) AS position
FROM {table_name}
) b
ON a.userid = b.userid
but keep in mind that you will need to run the update every time the table is updated, so performance may be an issue if it's a decent size table that gets updated a lot.
Also consider using DENSE_RANK() instead of RANK() when you want to increment the ranking of your 'position' by 1 as the 'points' change. RANK() will do what you want, though it will create number sequence gaps according to how many duplicate 'userids' are equal in 'points' standing's (if that's ever the case in your spec).
Refer to this answer for the difference between them.
You can do something like this:
UPDATE t
SET position = t2.position
FROM table t
JOIN (
SELECT
userid,
points,
RANK() OVER (ORDER BY points DESC) AS position
FROM table) t2 ON t2.userid = t.userid
I've a status table and I want to fetch the latest details.
Slno | ID | Status | date
1 | 1 | Pass | 15-06-2015 11:11:00 - this is inserted first
2 | 1 | Fail | 15-06-2015 11:11:00 - this is inserted second
3 | 2 | Fail | 15-06-2015 12:11:11 - this is inserted first
4 | 2 | Pass | 15-06-2015 12:11:11 - this is inserted second
I use a window function with partition by ID order by date desc to fetch the first value.
Excepted Output :
2 | 1 | Fail | 15-06-2015 11:11:00 - this is inserted second
4 | 2 | Pass | 15-06-2015 12:11:11 - this is inserted second
Actual Output :
1 | 1 | Pass | 15-06-2015 11:11:00 - this is inserted first
3 | 2 | Fail | 15-06-2015 12:11:11 - this is inserted first
According to [http://docs.aws.amazon.com/redshift/latest/dg/r_Examples_order_by_WF.html], adding a second ORDER BY column to the window function may solve the problem. But I don't have any other column to differentiate the rows!
Is there another approach to solve the issue?
EDIT: I've added slno here for clarity. I don't have slno as such in the table!
My SQL:
with range as (
select id from status where date between 01-06-2015 and 30-06-2015
), latest as (
select status, id, row_number() OVER (PARTITION BY id ORDER BY date DESC) row_num
)
select * from latest where row_num = 1
If you don't have slno in your table, then you don't have any reliable information which row was inserted first. There is no natural order in a table, the physical order of rows can change any time (with any update, or with VACUUM, etc.)
You could use an unreliable trick: order by the internal ctid.
select *
from (
select id, status
, row_number() OVER (PARTITION BY id
ORDER BY date, ctid) AS row_num
from status -- that's your table name??
where date >= '2015-06-01' -- assuming column is actually a date
and date < '2015-07-01'
) sub
where row_num = 1;
In absence of any other information which row came first (which is a design error to begin with, fix it!), you might try to save what you can using the internal tuple ID ctid
In-order sequence generation
Rows will be in physical order when inserted initially, but that can change any time with any write operation to the table or VACUUM or other events.
This is a measure of last resort and it will break.
Your presented query was invalid on several counts: missing column name in 1st CTE, missing table name in 2nd CTE, ...
You don't need a CTE for this.
Simpler with DISTINCT ON (considerations for ctid apply the same):
SELECT DISTINCT ON (id)
id, status
FROM status
WHERE date >= '2015-06-01'
AND date < '2015-07-01'
ORDER BY id, date, ctid;
Select first row in each GROUP BY group?
I have a user activity table. I want to see a difference between each process in minutes.
To be more specific here is a partial data from table.
Date |TranType| Prod | Loc
-----------------------------------------------------------
02/27/12 3:17:21 PM | PICK | LIrishGreenXL | E01C015
02/27/12 3:18:18 PM | PICK | LAntHeliconiaS | E01A126
02/27/12 3:19:00 PM | PICK | LAntHeliconiaL | E01A128
02/27/12 3:19:07 PM | PICK | LAntHeliconiaXL | E01A129
I want to retrieve time difference in minutes, between first and second process, than second and third and ....
Thank you
Something like this will work in MS SQL, just change the field names to match yours:
select a.ActionDate, datediff(minute,a.ActionDate,b.ActionDate) as DiffMin
(select ROW_NUMBER() OVER(ORDER BY ActionDate) AS Row, ActionDate
from [dbo].[Attendance]) a
inner join
(select ROW_NUMBER() OVER(ORDER BY ActionDate) AS Row, ActionDate
from [dbo].[Attendance]) b
on a.Row +1 = b.Row