I have a View called LOGS2016 that is created from 12 individual "Month" tables of naming convention: LOG201601, LOG201602, and so on..
To do normal date range lookups, I'll typically select all records from LOGS2016 and do a DATEADD function on each record. Obviously not the fastest method.
My filter is only ever attempting to find "previous 30 days worth of activity from today", so what I'd like to do is use only 2 tables to cover this query, as opposed to the entire year VIEW which is 12 tables worth of records.
Is there a way to do a join or union on the current month's table and the previous month's table instead of using the annual VIEW? (I can get current year and month using PHP if necessary)
What I've tried (and is still very slow):
-- This takes 11 Seconds
SELECT * FROM LOG201612 WITH (NOLOCK)
UNION ALL
SELECT * FROM LOG201701 WITH (NOLOCK)
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 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
I have a table of database size information. The data is collected daily. However, some days are missed due to various reasons. Additionally we have databases which come and go over or the size does not get recorded for several databases for a day or two. This all leads to very inconsistent data collection regarding dates. I want to construct a SQL procedure which will generate a percentage of change between any two dates (1 week, monthly, quarterly, etc.) for ALL databases The problem is what to do if a chosen date is missing (no rows for that date or no row for one or more databases for that date). What I want to be able to do is get the nearest available date for each database for the two dates (begin and end).
For instance, if database Mydb has these recording dates:
2015-05-03
2015-05-04
2015-05-05
2015-05-08
2015-05-09
2015-05-10
2015-05-11
2015-05-12
2015-05-14
and I want to compare 2015-05-06 with 2015-05-14
The 2015-05-07 date is missing so I would want to use the next available date which is 2015-05-08. Keep in mind, MyOtherDB may only be missing the 2015-05-06 date but have available the 2015-05-07 date. So, for MyOtherDb I would be using 2015-05-07 for my comparison.
Is there a way to proceduralize this with SQL WITHOUT using a CURSOR?
You're thinking too much into this, simple do a "BETWEEN" function in your where clause that takes the two parameters.
In your example, if you perform the query:
SELECT * FROM DATABASE_AUDIT WHERE DATE BETWEEN param1 /*2015-05-06*/ and param2 /*2015-05-14*/
It will give you the desired results.
select (b.dbsize - a.dbsize ) / a.dbsize *100 dbSizecChangePercent from
( select top 1 * from dbAudit where auditDate = (select min(auditDate) from dbAudit where auditDate between '01/01/2015' and '01/07/2015')) a
cross join
(select top 1 * from dbAudit where auditDate = (select max(auditDate) from dbAudit where auditDate between '01/01/2015' and '01/07/2015')) b
The top 1 can be replaced by a group by. This was assuming only 1 db aduit per day
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
I'm writing a report in Crystal Reports XI Developer that runs a stored procedure in a SQL Server 2005 database. The record set returns a summary from log table grouped by Day and Hour.
Currently my query looks something like this:
SELECT
sum(colA) as "Total 1",
day(convert(smalldatetime, convert(float, Timestamp) / 1440 - 1)) as "Date",
datepart(hh, convert(smalldatetime, convert(float, Timestamp) / 1440 - 1)) as "Hour"
`etc...`
GROUP BY
Day, Hour
Ignore the date insanity, I think the system designers were drinking heavily when they worked out how to store their dates.
My problem is this: since there are not always records from each hour of the day, then I end up with gaps, which is understandable, but I'd like Crystal to be able to report on the entire 24 hours regardless of whether there is data or not.
I know I can change this by putting the entire query in a WHILE loop (within the stored procedure) and doing queries on the individual hours, but something inside me says that one query is better than 24.
I'd like to know if there's a way to have Crystal iterate through the hours of the day as opposed to iterating through the rows in the table as it normally does.
Alternatively, is there a way to format the query so that it includes the empty hour rows without killing my database server?
Here's how I solved this problem:
Create a local table in your SQL-Server. Call it "LU_Hours".
This table will have 1 integer field (called "Hours") with 24 rows. Of course, the values would be 1 through 24.
Right join this onto your existing query.
You might need to tweak this to make sure the nulls of empty hours are handled to your satisfaction.
You could use a WITH clause to create the 24 hours, then OUTER JOIN it.
WITH hours AS (
SELECT 1 AS hour
UNION
SELECT 2 AS hour
...
SELECT 24 AS hour
)
SELECT *
FROM hours h
LEFT OUTER JOIN [your table] x ON h.hour=x.datepart(hh, convert(smalldatetime, convert(float, Timestamp) / 1440 - 1))
This SQL would need to added to a Command.
Group as necessary in the SQL or the report.