Hi im looking to compare several rows and check if a certain condition is true/false.
The tables has several columns the ones im interested in are:
Events.Badgeno
Events.Name
Events.Date
Events.Time
Events.Region_id
Events.Data
The region ID can either be 1 or 2.
I want to check weather the same badgeno registers with a different region within a specified date/time difference say 10 mins. (Could be 10 mins before or 10 mins after).
I'm looking to show the records which don't have a record against the 2 regions.
As a further note it should only be within the first and last records of that badge per day.
Normally each record should have a region 1 and 2 record at the start and end. But there maybe multiple region 1's through out the day.
Any suggestions for the best method?
Id Date Time Name Badgeid Region
3385033 27/02/2014 08:16:11 FirstName Surname 5304 2
I think something like this would work
SELECT e.Badgeno,e.Name, e.Date, e.Time,e.Region_id, e.Data
FROM events e
INNER JOIN events e1 ON e1.BadgeNo = e.BadgeNo AND e1.Region_id <> e.RegionId AND DATEDIFF(minutes,e1.date + e1.time,e.date + e.time) > -10 AND DATEDIFF(minutes,e1.date + e1.time,e.date + e.time) < 10
WHERE e1.Region_id IS NULL
you should provide sample data.
This Query is not complete,you can try something with
row_number/rank/dense, partition and check thus number column
generated .
select *,
row_number()over(partition by badgeno,regionno order by badge no)rn from table
where condition of date time
Related
Well I'm using Postgresql(but it won't matter if you can advise a solution in any SQL syntax), I have a table like
employee
department
salary
1
sales
30,000
2
sales
25,000
3
marketing
45,000
4
marketing
55,000
so on...
What I want to achieve is:
employee
department
salary
difference
1
sales
30,000
0/null
2
sales
25,000
5,000
3
marketing
45,000
0/null
4
marketing
55,000
10,000
So technically I want to extract the value difference of consecutive rows, however I can't use the window functions (I don't know why, but it is must to avoid in this challenge)
in a perfect world, we'd be able to do lag() or lead() functions partitioned by department name and store the value difference in other column, but I don't know how to do it without them.
I tried subqueries multiple ways, but every time I ended up having NULL or 0 in new a column
You can use a self-join to table itself and join each employee with the previous row within the same department.
SELECT t1.employee, t1.department, t1.salary, ABS(t2.salary - t1.salary) AS difference
FROM tab t1
LEFT JOIN tab t2
ON t1.department = t2.department AND t1.employee = t2.employee +1
I have a table of stock symbols in a database called FINALDB, some of which are also in the NYSE table. Lets say that i only have 3 distinct ticker symbols there.
I want to reference all rows in the FINALDB.NYSE table which match these 3 tickers and remove those rows and write them to a table in a different database. what is happening is that the rows are in fact getting removed, but I am getting 3x the rows expected. It's as if is is doing the deletion 3 times because there are three tickers in the [FINALDB].[dbo].STOCKS table. if I have 50 tickers in that table that match tickers in the NYSE table, I am getting 50x the amount of rows deleted as I am expecting. it's performing a delete operation for each occurrence of a ticker in the other table. What am I doing wrong?
Thanks
This is my code:
DECLARE #currentDate date = CONVERT(date, GETDATE())
DELETE FROM FINALDB.dbo.NYSE
OUTPUT DELETED.Ticker, DELETED.Exchange,
DELETED.[Date], DELETED.[Open],
DELETED.[High], DELETED.[Low],
DELETED.[Close], DELETED.[Volume],
GETDATE() AS Delete_Date
INTO [STAGEDB].[dbo].Deleted_Data_Type5
FROM FINALDB.dbo.NYSE
INNER JOIN [FINALDB].[dbo].STOCKS ON [FINALDB].[dbo].STOCKS.[Ticker] = [FINALDB].[dbo].NYSE.[Ticker]
AND [FINALDB].[dbo].STOCKS.[Exchange] = [FINALDB].[dbo].NYSE.[Exchange]
AND [FINALDB].[dbo].STOCKS.[Date] = #currentDate
thanks for the suggestion of changing it to a SELECT to compare results. I failed to include the top part of the script, which runs in python.
for ex in exchanges:
This was resulting in the Stock exchange (singapore) being referenced 3 times, one for each occurrence of the symbol in the table.
Name: Combined, dtype: object
0 SG
1 SG
2 SG
So, it was doing the delete operation over and over (how there was anything left to delete on subsequent runs escapes me)
I need to count records by days, even if in the day were no records.
Count by days, sure, easy.
But how i can make it to print information, that 'in day 2018-01-10 was 0 records)
Should I use connect by level? Please, any help would be good. Can't use plsql, just oracle sql
First you generate every date that you want in an inline view. I chose every date for the current year because you didn't specify. Then you left outer join on date using whichever date field you have in that table. If you count on a non-null field from the source table then it will count 0 rows on days where there is no join.
select Dates.r, count(tablename.id)
from (select trunc(sysdate,'YYYY') + level - 1 R
from dual
connect by level <= trunc(add_months(sysdate,12),'YYYY') - trunc(sysdate,'YYYY')) Dates
left join tablename
on trunc(tablename.datefield) = Dates.r
group by Dates.r
INTRODUCTION TO DATABASE TABLE BEING USED -
I am working on a “Stock Market Prices” based Database Table. My table has got the data for the following FIELDS –
ID
SYMBOL
OPEN
HIGH
LOW
CLOSE
VOLUME
VOLUME CHANGE
VOLUME CHANGE %
OPEN_INT
SECTOR
TIMESTAMP
New data gets added to the table daily “Monday to Friday”, based on the stock market price changes for that day. The current requirement is based on the VOLUME field, which shows the volume traded for a particular stock on daily basis.
REQUIREMENT –
To get the Average and Total Volume for last 10,15 and 30 Days respectively.
METHOD USED CURRENTLY -
I created these 9 SEPARATE QUERIES in order to get my desired results –
First I have created these 3 queries to take out the most recent last 10,15 and 30 dates from the current table:
qryLast10DaysStored
qryLast15DaysStored
qryLast30DaysStored
Then I have created these 3 queries for getting the respective AVERAGES:
qrySymbolAvgVolume10Days
qrySymbolAvgVolume15Days
qrySymbolAvgVolume30Days
And then I have created these 3 queries for getting the respective TOTALS:
qrySymbolTotalVolume10Days
qrySymbolTotalVolume15Days
qrySymbolTotalVolume30Days
PROBLEM BEING FACED WITH CURRENT METHOD -
Now, my problem is that I have ended up having these so many different queries, whereas I wanted to get the output into One Single Query, as shown in the Snapshot of the Excel Sheet:
http://i49.tinypic.com/256tgcp.png
SOLUTION NEEDED -
Is there some way by which I can get these required fields into ONE SINGLE QUERY, so that I do not have to look into multiple places for the required fields? Can someone please tell me how to get all these separate queries into one -
A) Either by taking out or moving the results from these separate individual queries to one.
B) Or by making a new query which calculates all these fields within itself, so that these separate individual queries are no longer needed. This would be a better solution I think.
One Clarification about Dates –
Some friend might think why I used the method of using Top 10,15 and 30 for getting the last 10,15 and 30 Date Values. Why not I just used the PC Date for getting these values? Or used something like -
("VOLUME","tbl-B", "TimeStamp BETWEEN Date() - 10 AND Date()")
The answer is that I require my query to "Read" the date from the "TIMESTAMP" Field, and then perform its calculations accordingly for LAST / MOST RECENT "10 days, 15 days, 30 days” FOR WHICH THE DATA IS AVAILABLE IN THE TABLE, WITHOUT BOTHERING WHAT THE CURRENT DATE IS. It should not depend upon the current date in any way.
If there is any better method or more efficient way to create these queries, then please enlighten.
You have separate queries to compute 10DayTotalVolume and 10DayAvgVolume. I suspect you can compute both in one query, qry10DayVolumes.
SELECT
b.SYMBOL,
Sum(b.VOLUME) AS 10DayTotalVolume,
Avg(b.VOLUME) AS 10DayAvgVolume
FROM
[tbl-B] AS b INNER JOIN
qryLast10DaysStored AS q
ON b.TIMESTAMP = q.TIMESTAMP
GROUP BY b.SYMBOL;
However, that makes me wonder whether 10DayAvgVolume can ever be anything other than 10DayTotalVolume / 10
Similar considerations apply to the 15 and 30 day values.
Ultimately, I think you want something based on a starting point like this:
SELECT
q10.SYMBOL,
q10.[10DayTotalVolume],
q10.[10DayAvgVolume],
q15.[15DayTotalVolume],
q15.[15DayAvgVolume],
q30.[30DayTotalVolume],
q30.[30DayAvgVolume]
FROM
(qry10DayVolumes AS q10
INNER JOIN qry15DayVolumes AS q15
ON q10.SYMBOL = q15.SYMBOL)
INNER JOIN qry30DayVolumes AS q30
ON q10.SYMBOL = q30.SYMBOL;
That assumes you have created qry15DayVolumes and qry30DayVolumes following the approach I suggested for qry10DayVolumes.
If you want to cut down the number of queries, you could use subqueries for each of the qry??DayVolumes saved queries, but try it this way first to make sure the logic is correct.
In that second query above, there can be a problem due to field names which start with digits. Enclose those names in square brackets or re-alias them in qry10DayVolumes, qry15DayVolumes, and qry30DayVolumes using alias names which begin with letters instead of digits.
I tested the query as written above with the "2nd Upload.mdb" you uploaded, and it ran without error from Access 2007. Here is the first row of the result set from that query:
SYMBOL 10DayTotalVolume 10DayAvgVolume 15DayTotalVolume 15DayAvgVolume 30DayTotalVolume 30DayAvgVolume
ACC-1 42909 4290.9 54892 3659.46666666667 89669 2988.96666666667
Access doesn't support most advanced SQL syntax and clauses, so this is a bit of a hack, but it works, and is fast on your small sample. You're basically running 3 queries but the Union clauses allow you to combine into one:
select
Symbol,
sum([10DayTotalVol]) as 10DayTotalV,
sum([10DayAvgVol]) as 10DayAvgV,
sum([15DayTotalVol]) as 15DayTotalV,
sum([15DayAvgVol]) as 15DayAvgV,
sum([30DayTotalVol]) as 30DayTotalV,
sum([30DayAvgVol]) as 30DayAvgV
from (
select
Symbol,
sum(volume) as 10DayTotalVol, avg(volume) as 10DayAvgVol,
0 as 15DayTotalVol, 0 as 15DayAvgVol,
0 as 30DayTotalVol, 0 as 30DayAvgVol
from
[tbl-b]
where
timestamp >= (select min(ts) from (select distinct top 10 timestamp as ts from [tbl-b] order by timestamp desc ))
group by
Symbol
UNION
select
Symbol,
0, 0,
sum(volume), avg(volume),
0, 0
from
[tbl-b]
where
timestamp >= (select min(ts) from (select distinct top 15 timestamp as ts from [tbl-b] order by timestamp desc ))
group by
Symbol
UNION
select
Symbol,
0, 0,
0, 0,
sum(volume), avg(volume)
from
[tbl-b]
where
timestamp >= (select min(ts) from (select distinct top 30 timestamp as ts from [tbl-b] order by timestamp desc ))
group by
Symbol
) s
group by
Symbol
Is there a way in MS access to return a dataset between a specific index?
So lets say my dataset is:
rank | first_name | age
1 Max 23
2 Bob 40
3 Sid 25
4 Billy 18
5 Sally 19
But I only want to return those records between 'rank' 2 and 4, so my results set is Bob, Sid and Billy? However, Rank is not part of the table, and this should be generated when the query is run. Why don't I use an autogenerated number, because if a record is deleted, this will be inconsistent, and what if I wanted the results in reverse!
This obviously very simple, and the reason I ask is because I am working on a product catalogue and I am looking for a more efficient way of paging through the returned dataset, so if I only return 1 page worth of data from the database this is obviously going to be quicker then return a complete set of 3000 records and then having to subselect from that set!
Thanks R.
Original suggestion:
SELECT * from table where rank BETWEEN 2 and 4;
Modified after comment, that rank is not existing in structure:
Select top 100 * from table;
And if you want to choose subsequent results, you can choose the ID of the last record from the first query, say it was ID 101, and use a WHERE clause to get the next 100;
Select top 100 * from table where ID > 100;
But these won't give you what you're looking for either, I bet.
How are you calculating rank? I assume you are basing it on some data in another dataset somewhere. If so, create a function, do a table join, or do something that can calculate rank based on values in other table(s), then you can do queries based on the rank() function.
For example:
select *
from table
where rank() between 2 and 4
If you are not calculating rank based on some data somewhere, there really isn't a way to write this query, and you might as well be returning three random rows from the table.
I think you need to use a correlated subquery to calculate the rank on the fly e.g. I'm guessing the rank is based on name:
SELECT T1.first_name, T1.age,
(
SELECT COUNT(*) + 1
FROM MyTable AS T2
WHERE T1.first_name > T2.first_name
) AS rank
FROM MyTable AS T1;
The bad news is the Access data engine is poorly optimized for this kind of query; in my experience, performace will start to noticeably degrade beyond a few hundred rows.
If it is not possible to maintain the rank on the db side of the house (e.g. high insertion environment) consider doing the paging on the client side. For example, an ADO classic recordset object has properties to support paging (PageCount, PageSize, AbsolutePage, etc), something for which DAO recordsets (being of an older vintage) have no support.
As always, you'll have to perform your own timings but I suspect that when there are, say, 10K rows you will find it faster to take on the overhead of fetching all the rows to an ADO recordset then finding the page (then perhaps fabricate smaller ADO recordset consisting of just that page's worth of rows) than it is to perform a correlated subquery to only fetch the number of rows for the page.
Unfortunately the LIMIT keyword isn't available in MS Access -- that's what is used in MySQL for a multi-page presentation. If you can write an order key into the results table, then you can use it something like this:
SELECT TOP 25 MyOrder, Etc FROM Table1 WHERE MyOrder in
(SELECT TOP 55 MyOrder FROM Table1 ORDER BY MyOrder DESC)
ORDER BY MyOrder ASCENDING
If I understand you correctly, there is ionly first_name and age columns in your table. If this is the case, then there is no way to return Bob, Sid, and Billy with a single query. Unless you do something like
SELECT * FROM Table
WHERE FirstName = 'Bob'
OR FirstName = 'Sid'
OR FirstName = 'Billy'
But I think that this is not what you are looking for.
This is because SQL databases make no guarantee as to the order that the data will come out of the database unless you specify an ORDER BY clause. It will usually come out in the same order it was added, but there are no guarantees, and once you get a lot of rows in your table, there's a reasonably high probability that they won't come out in the order you put them in.
As a side note, you should probably add a "rank" column (this column is usually called id) to your table, and make it an auto incrementing integer (see Access documentation), so that you can do the query mentioned by Sev. It's also important to have a primary key so that you can be certain which rows are being updated when you are running an update query, or which rows are being deleted when you run a delete query. For example, if you had 2 people named Max, and they were both 23, how you delete 1 row without deleting the other. If you had another auto incrementing unique column in there, you could specify the unique ID in your query to delete only one.
[ADDITION]
Upon reading your comment, If you add an autoincrement field, and want to read 3 rows, and you know the ID of the first row you want to read, then you can use "TOP" to read 3 rows.
Assuming your data looks like this
ID | first_name | age
1 Max 23
2 Bob 40
6 Sid 25
8 Billy 18
15 Sally 19
You can wuery Bob, Sid and Billy with the following QUERY.
SELECT TOP 3 FirstName, Age
From Table
WHERE ID >= 2
ORDER BY ID