Anyones help on this would be very much appreciated..
I have a Table with lots of fields but the two I want to query is
'MachineId' <- Id Field
'DateLogged' <- Date and time Service Call Logged
The MachineId represents a physical machine onsite. What i'm after is, has the machine had 3 calls logged to it within 7 days. Not just in the last seven days but in the lifetime of the machine.
I wanted to return a table with the MachineId's that hit this criteria.
I'm banging my head. Any help would be much appreciated.
You can do this with a self-join and aggregation. The idea is to find any matching record within a week after each row in the table. Then aggregate by the original row and count the number of matches:
select t.MachineId, t.DateLogged, count(*) as NumIncidents
from table t inner join
table t2
on t.MachineId = t2.MachineId and
t2.DateLogged between t.DateLogged and dateadd("d", 6, t.DateLogged)
group by t.MachineId, t.DateLogged
having count(*) >= 3;
Related
Thank you for taking the time to read this, it is probably a very basic question. Most search queries I did seemed a bit more in depth to the INNER JOIN operator.
Basically my question is this: I have a shipping and receiving table with dates on when the item was either shipped or received. In the shipping table (tbl_shipping) the date row is labeled as trans_out_date and for the receiving table (tbl_receiving) the date row is labeled as trans_in_date.
I can view transactions set on either table from a user entered form but I want to populate a table with information pulled from both tables where the criteria meets. ie. If the receiving table has 10 transactions done in April and 5 in June and the shipping table has 15 transactions in April and 10 in June... when the user wants to see all transactions in June, it will populate the 15 transactions that occurred in June.
As of right now, I can pull only from 1 table with
SELECT *
FROM tbl_shipping
WHERE trans_out_date >= ‘from_date’
AND trans_out_date <= ‘to_date’
Would this be the appropriate syntax for what I am looking to achieve?
SELECT *
FROM tbl_shipping
INNER JOIN tbl_receiving ON tbl_shipping.trans_out_date = tbl_receiving.trans_in_date
WHERE
tbl_shipping.trans_out_date >= ‘from_date’
AND tbl_shipping.trans_out_date <= ‘to_date’
Thank you again in advance for reading this.
You appear to want union all rather than a join:
SELECT s.item, s.trans_out_date as dte, 'shipped' as which
FROM tbl_shipping S
WHERE s.trans_out_date >= ? AND
s.trans_out_date <= ?
UNION ALL
SELECT r.item, NULL, r.trans_in_date as dte, 'received'
FROM tbl_receiving r
WHERE r.trans_out_date >= ? AND
r.trans_out_date <= ?
ORDER BY dte;
Notes:
A JOIN can cause problems due to data that goes missing (because dates don't line up) or data that gets duplicated (because there are multiple dates).
The ? is for a parameter. If you are calling this from an application, use parameters!
You can include additional columns for more information in the result set.
This may not be the exact result format you want. If not, ask another question with sample data and desired results.
I have the following table, let's call it Names:
Name Id Date
Dirk 1 27-01-2015
Jan 2 31-01-2015
Thomas 3 21-02-2015
Next I have the another table called Consumption:
Id Date Consumption
1 26-01-2015 30
1 01-01-2015 20
2 01-01-2015 10
2 05-05-2015 20
Now the problem is, that I think that doing this using SQL is the fastest, since the table contains about 1.5 million rows.
So the problem is as follows, I would like to match each Id from the Names table with the Consumption table provided that the difference between the dates are the lowest, so we have: Dirk consumes on 27-01-2015 about 30. In case there are two dates that have the same "difference", I would like to calculate the average consumption on those two dates.
While I know how to join, I do not know how to code the difference part.
Thanks.
DBMS is Microsoft SQL Server 2012.
I believe that my question differs from the one mentioned in the comments, because it is much more complicated since it involves comparison of dates between two tables rather than having one date and comparing it with the rest of the dates in the table.
This is how you could it in SQL Server:
SELECT Id, Name, AVG(Consumption)
FROM (
SELECT n.Id, Name, Consumption,
RANK() OVER (PARTITION BY n.Id
ORDER BY ABS(DATEDIFF(d, n.[Date], c.[Date]))) AS rnk
FROM Names AS n
INNER JOIN Consumption AS c ON n.Id = c.Id ) t
WHERE t.rnk = 1
GROUP BY Id, Name
Using RANK with PARTITION BY n.Id and ORDER BY ABS(DATEDIFF(d, n.[Date], c.[Date])) you can locate all matching records per Id: all records with the smallest difference in days are going to have rnk = 1.
Then, using AVG in the outer query, you are calculating the average value of Consumption between all matching records.
SQL Fiddle Demo
The title is a bit confusing but I'll explain my problem here:
So i have a database table with millions of lines of spending data broken up into different time fields (period1 - period14). Now what i need to do is write a query that will return the records where the spending in one period is equal to the spending in a different period within the same record. So basically that means if i have a reecord where the spending in period1 is $100 and then the spending in period5 is also $100, it will add that record to a new table. I tried something like the code below but since I'm very new to access it is rather complex/inefficient and also doesn't do what i need it to.
INSERT INTO Contracts
SELECT *
FROM SPENDDETAIL
WHERE (SPENDDETAIL.Period1 = SPENDDETAIL.Period2 OR SPENDDETAIL.Period3 [...] OR SPENDDETAIL.Period14)
AND (SPENDDETAIL.Period1 <> 0 OR SPENDDETAIL.Period2 <> 0 [...] OR SPENDDETAIL.Period14 <> 0);
Any help much appreciated, thanks!
Oh also i know this code snippet would only return the records where the period1 spend equals the spend from any of the other periods it was just a beginning attempt at making the query do what i need it to.
Something along these lines might get you started:
SELECT Id, Value, COUNT(*) FROM
(SELECT Id AS Id, 1 AS Period, Period1 AS Value FROM SPENDDETAIL
UNION ALL
SELECT Id AS Id, 2 AS Period, Period2 AS Value FROM SPENDDETAIL
UNION ALL
SELECT Id AS Id 3 AS Period, Period3 AS Value FROM SPENDDETAIL
etc...) x
GROUP BY Id, Value
HAVING COUNT(*) > 1
Where Id is some unique identifier for each row of the data (assuming there is such a thing).
This will give you a list of Ids and matching values.
I have SQL like this (where $ytoday is 5 days ago):
$sql = 'SELECT Count(*), created_at FROM People WHERE created_at >= "'. $ytoday .'" AND GROUP BY DATE(created_at)';
I want this to return a value for every day, so it would return 5 results in this case (5 days ago until today).
But say Count(*) is 0 for yesterday, instead of returning a zero it doesn't return any data at all for that date.
How can I change that SQLite query so it also returns data that has a count of 0?
Without convoluted (in my opinion) queries, your output data-set won't include dates that don't exist in your input data-set. This means that you need a data-set with the 5 days to join on to.
The simple version would be to create a table with the 5 dates, and join on that. I typically create and keep (effectively caching) a calendar table with every date I could ever need. (Such as from 1900-01-01 to 2099-12-31.)
SELECT
calendar.calendar_date,
Count(People.created_at)
FROM
Calendar
LEFT JOIN
People
ON Calendar.calendar_date = People.created_at
WHERE
Calendar.calendar_date >= '2012-05-01'
GROUP BY
Calendar.calendar_date
You'll need to left join against a list of dates. You can either create a table with the dates you need in it, or you can take the dynamic approach I outlined here:
generate days from date range
I have 2 tables with no relations, both tables have different number of columns, but there are a few columns that are the same but hold different data. I was able to create a function or view of only the data I wanted, but when I try to count the data by filtering the date, I always get the wrong count in return. Let me explain by showing the 2 functions and what I try to do:
Function 1
ID - number from 1 to 8
data sent - YES or NO
Date - date value
Function 2
ID - number from 1 to 8
data sent - yes or no
date - date value
Upon running both separately, I get all the rows from the tables and everything looks good.
Then I try to add the following to each function:
select
count([data sent]), ID
from function1
Where (date between #date1 and #date2)
group by ID
The above statement works great and gives me the right result for each function.
Now I thought what if I want to add those 2 functions into one and get the count from both functions on 1 page.
So I created the following function:
Function 3
select
count(Function1.[data sent]) as Expr1,
Function1.id,
count(Function2.[data sent]) as Expr2,
Function1.date
from
Function1
LEFT OUTER JOIN
Function2 on Function1.id = Function2.id
Where
(Function1.date between #date1 and #date2)
group by
Function1.id
Upon running the above, I get the following table:
ID Expr1 Expr2
On both Expr1 and Expr2, I get results which I am not sure where they come from. I guess something is being multiplied by 100000 since one table holds almost 15000 rows and the other around 5000 rows.
What I would like to know first is if it possible at all to be able to filter by date and count records from both table at the same time. If anyone need more information please let me know and I will be glad to share and explain more.
Thank you
The LEFT OUTER JOIN is taking each row of the left table, finding ALL of the rows in the right table with the same id field, and creating that many rows in the result table. Since id isn't what we usually think of as an identity field (it looks more like a "deviceId" or something), you'll get lots of matches for each one. Repeat 15000 times and you get your combinatorial explosion.
Tip: To debug things like this, you can create sample tables with a tiny subset of the real data, say 10 rows from each, and run your query on them. You'll see the issue immediately.
It's possible to filter by date. It's hard to recommend an actual solution without better understanding your phrase "I want to add those 2 functions into one and get the count from both functions on 1 page".
Why can't you create a temporary table for each function then join them together?
Maybe subqueries can help you to achieve what you want:
SELECT
ID = COALESCE(f1.ID, f2.ID),
Date = COALESCE(f1.Date, f2.Date),
f1.Expr1,
f2.Expr2
FROM (
SELECT
ID,
Date,
Expr1 = COUNT([data sent])
FROM Function1
WHERE Date BETWEEN #date1 AND #date2
GROUP BY
ID,
Date
) f1
FULL JOIN (
SELECT
ID,
Date,
Expr2 = COUNT([data sent])
FROM Function2
WHERE Date BETWEEN #date1 AND #date2
GROUP BY
ID,
Date
) f2
ON f1.ID = f2.ID AND f1.Date = f2.Date
This query also uses full (outer) join instead of left join, in case the right side of the join contains rows that have no match in the left side (and you want those rows).