I have a MySQL table shown in a picture. The result I want to get is in the "average" column:
I would like create query to calculate the average value since the beginning of the year (1 January). Each row contains the average between the beginning of the year and current row. Each 1 January the average should be reset to zero.
One method uses a correlated subquery:
select date, value,
(select avg(value) from t t2 where t2.date <= t.date) as running_avg
from t
order by date;
This makes some assumptions:
"a", "b" and so on are numbers, not strings.
a+b/2 really means (a + b) / 2 and so on.
If you need from only this year, then the condition needs to include the year.
Related
I have a table containing stock market data (open, hi, lo, close prices) but in a random order of date:
Date Open Hi Lo Close
12/10/2019 313.82 314.54 312.81 313.58
11/22/2019 311.09 311.24 309.85 310.96
11/25/2019 311.98 313.37 311.98 313.37
11/26/2019 313.41 314.28 313.06 314.08
11/27/2019 314.61 315.48 314.37 315.48
11/29/2019 314.86 315.13 314.06 314.31
12/2/2019 314.59 314.66 311.17 311.64
12/3/2019 308.65 309.64 307.13 309.55
I have another value in a PHP variable (say $BaseValue),and a start date and end date ($startdt and $enddt).
1) My requirement is to pick-up the value from the HI column, if it exceeds the $BaseValue on the very FIRST date in a chronological order between the given start and end dates.
For example, if the $BaseValue=314, startdt=11/22, enddt=12/2, then I want to retrieve the Date (11/26/19) as it is the earliest date on which the Hi value (314.28) exceeded the $Basevalue within the given date range. The select statement should return both the Hi value (314.28) and the Date (11/26/19).
2) Additionally, I also need to retrieve the HIGHEST value and date from the HI column during the given date duration. In the above scenario, it should return 315.48 and corresponding date 11/27.
The table is NOT in a chronological order - its randomly filled.
I am unable to get the first query at all with the use of MAX function and its various combinations. Makes me wonder if that is possible at all in SQL or not.
While the second is straightforward, I was wondering if it is more efficient and less complex to club the two queries and get the four values in one single shot.
Any ideas on how can I approach the need to fulfill this requirement please?
Thanks
You could use two subqueries for filtering, one per criteria, like:
select t.*
from mytable t
where
t.date = (
select min(t1.date)
from mytable t1
where t1.date between :datedt and :enddt and t1.hi >= :basevalue
)
or t.hi = (
select max(t1.hi)
from mytable t1
where t1.date between datedt and :enddt and t1.hi >= :basevalue
)
Another option is to union two queries with orer by and limit:
(
select t.*
from mytable
where t.date between :datedt and :enddt and t1.hi >= :basevalue
order by t.date
limit 1
)
union
(
select t.*
from mytable t
where t.date between :datedt and :enddt and t1.hi >= :basevalue
order by t.hi desc, t.date
limit 1
)
Please note that both queries do not do exactly the same thing. If there are ties for the highest hi in the period, the first query will return all ties, while the second will pick the earliest one. It's up to you to decide which solution better fits your use case.
I am trying to create an RDL file and I need a tablix to appear in the following format.
This is how I want the results to look
The values that are in bold are hard coded values. This is how the output from the SELECT statement in the datasets looks
SQL Output
I don't know how to make the values that output from the database match with the hard coded values in the RDL file. The 'Day' field represents a day in the month and the 'Num' field represents the number of sales that were on the day. The above example shows that on the first day of the month, there were 100 sales made. I need the tablix to output in that specific format.
If the day isn't in the SQL output (no sales made that day), I want it to output blank and/or 0.
Any idea how this could be accomplished?
Use a CTE to create rows for each day you need and then join your results on. A starting point for you CTE could be:
;WITH nums AS
(SELECT 1 AS value
UNION ALL
SELECT value + 1 AS value
FROM nums
WHERE nums.value <= 30)
SELECT *
FROM nums
You'll probably then want to modify the total days based on the month you are viewing.
You can do this using lookups, but you would need to hard code a lookup in each cell. e.g. for day 1
=lookup(cint(1),Fields!Day.Value,Fields!Num.Value,"Dataset1")
A faster way would be to create a tablix on the dataset filtered on the first ten days:
=Switch(
Fields!DAY.Value <= 10 and Fields!DAY.Value >=1,"Include",
True,"Exclude"
)
Create a row group on days, then create a column with day and num, and columns with Fields!DAY.Value+10 and Fields!DAY.Value+20 with the following lookups:
=lookup(Fields!DAY.Value+10,Fields!DAY.Value,Fields!NUM.Value,"DataSet1")
=lookup(Fields!DAY.Value+20,Fields!DAY.Value,Fields!NUM.Value,"DataSet1")
I have a MySQL DB where one column is the DATE and the other column is the SIGNAL. Now I would like to calculate the SUM over Signal for 4 days each.
f.e.
SUM(signal over DATE1,DATE2,DATE3,DATE4)
SUM(signal over DATE5,DATE6,DATE7,DATE8)
...
whereas Date_N = successor of DATE_N-1 but need not to be the day before
Moreless the algo should be variable in the days group. 4 ist just an example.
Can anyone here give me an advice how to perform this in MySQL?
I have found this here group by with count, maybe this could be helpful for my issue?
Thanks
Edit: One important note: My date ranges have gaps in it. you see this in the picture below, in the column count(DISTINCT(TradeDate)). It should be always 4 when I have no gaps. But I DO have gaps. But when I sort the date descending, I would like to group the dates together always 4 days, f.e. Group1: 2017-08-22 + 2017-08-21 + 2017-08-20 + 2017-08-19, Group2: 2017-08-18 + 2017-08-17+2017-08-15+2017-08-14, ...
maybe I could map the decending dateranges into a decending integer autoincrement number, then I would have a number without gaps. number1="2017-08-17" number2="2017-08-15" and so on ..
Edit2:
As I see the result from my table with this Query: I might I have double entries for one and the same date. How Can I distinct this date-doubles into only one reprensentative?
SELECT SUM(CondN1),count(id),count(DISTINCT(TradeDate)),min(TradeDate),max(TradeDate) ,min(TO_DAYS(DATE(TradeDate))),id FROM marketstat where Stockplace like '%' GROUP BY TO_DAYS(DATE(TradeDate)) DIV 4 order by TO_DAYS(DATE(TradeDate))
SUM() is a grouping function, so you need to GROUP BY something. That something should change only every four days. Let's start by grouping by one day:
SELECT SUM(signal)
FROM tableName
GROUP BY date
date should really be of type DATE, like you mentioned, not DATETIME or anything else. You could use DATE(date) to convert other date types to dates. Now we need to group by four dates:
SELECT SUM(signal)
FROM tableName
GROUP BY TO_DAYS(date) DIV 4
Note that this will create an arbitary group of four days, if you want control over that you can add a term like this:
SELECT SUM(signal)
FROM tableName
GROUP BY (TO_DAYS(date)+2) DIV 4
In the meantime and with help of KIKO I have found the solution:
I make a temp table with
CREATE TEMPORARY TABLE if not EXISTS tradedatemaptmp (id INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY) SELECT Tradedate AS Tradedate, CondN1, CondN2 FROM marketstat WHERE marketstat.Stockplace like 'US' GROUP BY TradeDate ORDER BY TradeDate asc;
and use instead the originate tradedate the now created id in the temp table. So I could manage that - even when I have gaps in the tradedate range, the id in the tmp table has no gaps. And with this I can DIV 4 and get the always the corresponding 4 dates together.
I have attendance data for employees stored in the table attendance with the following column names:
emp_id (employee ID)
date
type (leave, absent, etc.)
(there are others but I'm omitting them for the sake of simplicity)
My objective is to retrieve all dates of the given month on which the employee was on leave (type = 'Leave') and the last leave taken in the last month, if any.
It's easy to do it using two queries (I'm using PHP to get process the data), but is there any way this can be done in a single query?
I'm answering my own question so as to close it. As #bpgergo pointed out in the comments, UNION will do the trick here.
SELECT * FROM table_name
WHERE type="Leave" AND
date <= (CURRENT_DATE() - 30)
Select the fields, etc you want then se a combined where clause using mysql's CURRENT_DATE() function. I subtracted 30 for 30 days in a month.
If date is a date column, this will return everyone who left 1 month or longer ago.
Edit:
If you want a specific date, change the 2nd month like this:
date <= (date_number - 30)
I have a table that contains three things: a start number, an end number, and a date which look something like this:
table: number2day
first last day
109288787 136388928 2013-06-29
136388929 144276079 2013-06-30
144276080 147295660 2013-07-01
Given today's date, I need to find the first value from days ago so I can compare it to a number within another query
I know that there is WHERE <col-name> IN (SUBQUERY) syntax but there is a similar statement that can use operators? >,<,=?
Something like:
WHERE num >= (SELECT first FROM number2day WHERE day = SUBDATE(CURDATE(), 3))
Here I only want to check if num is greater than first from 3 days ago. Any thoughts?
The ALL keyword should work for you here:
WHERE NUM >= ALL (SELECT first FROM number2day WHERE day = SUBDATE(CURDATE(), 3))