I have a Table with Orders. On that table I have a field CreatedAt (datetime2). Is it possible to create a select query that shows me how many orders there have been made on every weekday? Not between to dates but over the hole table.
Like:
Monday:52
Tuesday: 16
...
and so on for all 7 days in a week.
Try this:
select datepart(weekday,CreatedAt) weekday,count(*) count
from Table
group by datepart(weekday,CreatedAt)
Related
I am working in SQLServer database. I have the following scenario,
My application runs every weekday of the month, when it runs it puts an entry into the table 'CONTROL' into the 'businessDate' column.
Is there a way to find out what are the days the application did not run for a given month. Is it possible to achieve it in a single query ?
You need a calendar table. Then select from that table left joined to your CONTROL table on date, where the month is what you're looking for, and where the control table is null (to show just exclusions).
DECLARE #Month int = 1 //For January
SELECT BaseDate
FROM CalendarTable cal
LEFT OUTER JOIN ControlTable con
ON cal.BaseDate = con.businessDate //make sure to cast as a date if it's a datetime
WHERE MONTH(cal.BaseDate) = #Month
AND con.businessDate IS NULL
I'm looking for input on getting a COUNT of records that were 'active' in a certain date range.
CREATE TABLE member {
id int identity,
name varchar,
active bit
}
The scenario is one where "members" number fluctuate over time. So I could have linear growth where I have 10 members at the beginning of the month and 20 at the end. Currently We go off the number of CURRENTLY ACTIVE (as marked by an 'active' flag in the DB) AT THE TIME OF REPORT. - this is hardly accurate and worse, 6 months from now, my "members" figure may be substantially different than now. and Since I'm doing averages per user, if I run a report now, and 6 months from now - the figures will probably be different.
I don't think a simple "dateActive" and "dateInactive" will do the trick... due to members coming and going and coming back etc. so:
JOE may be active 12-1 and deactivated 12-8 and activated 12-20
so JOE counts as being a 'member' for 8 days and then 11 days for a total of 19 days
but the revolving door status of members means keeping a separate table (presumably) of UserId, status, date
CREATE TABLE memberstatus {
member_id int,
status bit, -- 0 for in-active, 1 for active
date date
} (adding this table would make the 'active' field in members obsolete).
In order to get a "good" Average members per month (or date range) - it seems I'd need to get a daily average, and do an average of averages over 'x' days. OR is there some way in SQL to do this already.
This extra "status" table would allow an accurate count going back in time. So in a case where you have a revenue or cost figure, that DOESN'T change or is not aggregate, it's fixed, that when you want cost/members for last June, you certainly don't want to use your current members count, you want last Junes.
Is this how it's done? I know it's one way, but it the 'better' way...
#gordon - I got ya, but I guess I was looking at records like this:
Members
1 Joe
2 Tom
3 Sue
MemberStatus
1 1 '12-01-2014'
1 0 '12-08-2014'
1 1 '12-20-2014'
In this way I only need the last record for a user to get their current status, but I can track back and "know" their status on any give day.
IF I'm understanding your method it might look like this
CREATE TABLE memberstatus {
member_id int,
active_date,
inactive_date
}
so on the 1-7th the record would look like this
1 '12-01-2014' null
and on the 8th it would change to
1 '12-01-2014' '12-08-2014'
the on the 20th
1 '12-01-2014' '12-08-2014'
1 '12-20-2014' null
Although I can get the same data out, it seems more difficult without any benefit - am i missing something?
You could also use a 2 table method to have a one-to-many relationship for working periods. For example you have a User table
User
UserID int, UserName varchar
and an Activity table that holds ranges
Activity
ActivityID int, UserID int, startDate date, (duration int or endDate date)
Then whenever you wanted information you could do something like (for example)...
SELECT User.UserName, count(*) from Activity
LEFT OUTER JOIN User ON User.UserID = Activity.UserID
WHERE startDate >= '2014-01-01' AND startDate < '2015-01-01'
GROUP BY User.UserID, User.UserName
...to get a count grouped by user (and labeled by username) of the times they were became active in 2014
I have used two main ways to accomplish what you want. First would be something like this:
CREATE TABLE [MemberStatus](
[MemberID] [int] NOT NULL,
[ActiveBeginDate] [date] NOT NULL,
[ActiveEndDate] [date] NULL,
CONSTRAINT [PK_MemberStatus] PRIMARY KEY CLUSTERED
(
[MemberID] ASC,
[ActiveBeginDate] ASC
)
Every time a member becomes active, you add an entry, and when they become inactive you update their ActiveEndDate to the current date.
This is easy to maintain, but can be hard to query. Another option is to do basically what you are suggesting. You can create a scheduled job to run at the end of each day to add entries to the table .
I recommend setting up your tables so that you store more data, but in exchange the structure supports much simpler queries to achieve the reporting you require.
-- whenever a user's status changes, we update this table with the new "active"
-- bit, and we set "activeLastModified" to today.
CREATE TABLE member {
id int identity,
name varchar,
active bit,
activeLastModified date
}
-- whenever a user's status changes, we insert a new record here
-- with "startDate" set to the current "activeLastModified" field in member,
-- and "endDate" set to today (date of status change).
CREATE TABLE memberStatusHistory {
member_id int,
status bit, -- 0 for in-active, 1 for active
startDate date,
endDate date,
days int
}
As for the report you're trying to create (average # of actives in a given month), I think you need yet another table. Pure SQL can't calculate that based on these table definitions. Pulling that data from these tables is possible, but it requires programming.
If you ran something like this once-per-day and stored it in a table, then it would be easy to calculate weekly, monthly and yearly averages:
INSERT INTO myStatsTable (date, activeSum, inactiveSum)
SELECT
GETDATE(), -- based on DBMS, eg., "current_date" for Postgres
active.count,
inactive.count
FROM
(SELECT COUNT(id) FROM member WHERE active = true) active
CROSS JOIN
(SELECT COUNT(id) FROM member WHERE active = true) inactive
I currently have a table called tempHouses that looks like:
avgprice | dates | city
dates are stored as yyyy-mm-dd
However I need to move the records from that table into a table called houses that looks like:
city | year2002 | year2003 | year2004 | year2005 | year2006
The information in tempHouses contains average house prices from 1995 - 2014.
I know I can use SUBSTRING to get the year from the dates:
SUBSTRING(dates, 0, 4)
So basically for each city in tempHouses.city I need to get the the average house price from the above years into one record.
Any ideas on how I would go about doing this?
This is an SQL Server approach, and a PIVOT may be a better, but here's one way:
SELECT City,
AVG(year2002) AS year2002,
AVG(year2003) AS year2003,
AVG(year2004) AS year2004
FROM (
SELECT City,
CASE WHEN Dates BETWEEN '2002-01-01T00:00:00' AND '2002-12-31T23:59:59' THEN avgprice
ELSE 0
END AS year2002,
CASE WHEN Dates BETWEEN '2003-01-01T00:00:00' AND '2003-12-31T23:59:59' THEN avgprice
ELSE 0
END AS year2003
CASE WHEN Dates BETWEEN '2004-01-01T00:00:00' AND '2004-12-31T23:59:59' THEN avgprice
ELSE 0
END AS year2004
-- Repeat for each year
)
GROUP BY City
The inner query gets the data into the correct format for each record (City, year2002, year2003, year2004), whilst the outer query gets the average for each City.
There many be many ways to do this, and performance may be the deciding factor on which one to choose.
The best way would be to use a script to perform the query execution for you because you will need to run it multiple times and you extract the data based on year. Make sure that the only required columns are city & row id:
http://dev.mysql.com/doc/refman/5.0/en/insert-select.html
INSERT INTO <table> (city) VALUES SELECT DISTINCT `city` from <old_table>;
Then for each city extract the average values, insert them into a temporary table and then insert into the main table.
SELECT avg(price), substring(dates, 0, 4) dates from <old_table> GROUP BY dates;
Otherwise you're looking at a combination query using joins and potentially unions to extrapolate the data. Because you're flattening the table into a single row per city it's going to be a little tough to do. You should create indexes first on the date column if you don't want the database query to fail with memory limits or just take a very long time to execute.
I've got a .Net application with an attendance table which has fields for a Start and End date. I'm struggling to show a graph of attendance for a given period. I can easily find how many rows are applicable on any given day using between but I can't get my head around pivoting results so that I can graph a count of rows per day. I could run a SQL query for every day individually and then graph the results but is there any way of doing this with T-SQL that I could then use to graph with?
Edit:-
Apologies as this is the first time I've asked a question here, but as huMpty duMpty has stated the question probably needs more clarification. I've got both a startdate and enddate column in the sql db and I need to count per day if the range between these dates falls between the range of the selection criteria. e.g if I've got a start date of 2013-01-01 and end date 2013-01-10 and I report on a period of 2013-01-09 to 2013-01-11 then i'm looking at getting a result for 1 for 2013-01-09 and 1 for 2013-01-10... Hope this make more sense and thanks for your assistance
I think you have a table with start and end dates; for a given date range, you would like to know the given number of records that fall on each date.
I believe this problem may be solved with a numbers table. I created a numbers table on the fly in a stored procedure, but I recommend creating a permanent numbers table in your production code. Here's the SQL Fiddle.
Create Table Attendance (
id int primary key identity(1,1) not null
,start_date date not null
,end_date date not null
);
Go
Insert Attendance(start_date, end_date)
Values ('1/1/2013', '1/10/2013')
,('1/10/2013', '1/15/2013')
,('2/20/2013', '3/1/2013');
Go
-- Create numbers table. See: Method 3 of http://stackoverflow.com/a/1407488/772086
With Numbers(Number) As
(
Select 1 As Number
Union All
Select Number + 1 From Numbers Where Number < 10000
)
Select
AttendanceDate = Convert(date, DateAdd(day,Numbers.number, '1/1/2000'))
,AttendanceCount = Count(*)
From dbo.Attendance
Join Numbers
On Numbers.Number
Between DateDiff(day, '1/1/2000', Attendance.start_date)
And DateDiff(day, '1/1/2000', Attendance.end_date)
-- Reporting range between 1/9 and 1/11
Where DateAdd(day,Numbers.number, '1/1/2000') Between '1/9/2013'
And '1/11/2013'
Group By Convert(date, DateAdd(day,Numbers.number, '1/1/2000'))
Option(MaxRecursion 10000);
All dates are in US format (m/d/yy) - you may want to switch those to the internationalized standard (yyyy-mm-dd) in your production code.
You said you wanted a count by day in a date range. That can be done with a COUNT with a GROUP BY clause.
I don't know your schema, but a solution might look like this:
declare #MyTable table
(
ID int identity(1,1) primary key clustered,
MyDate smalldatetime
)
insert into #MyTable (MyDate)
values
('2012-12-31'), -- before the date range, so not included in results
('2013-01-10'),
('2013-01-10'), -- appears twice
('2013-01-11'), -- appears once
('2013-01-12') -- after the date range, so not included in results
select * from #MyTable
select
MyDate,
count(*)
from #MyTable
where MyDate between '2013-01-09' and '2013-01-11'
group by MyDate
I have a table Customer_Complex_LoginLogs to log customer entrance.
I want to get the maximum number of entrances that has occurred on a single day (and I want to know the day that this occurred).
I know I should perform a group by TFEnteranceDate
How can I achieve this in TSQL ?
TableName :
Customer_Complex_LoginLogs
Table fields :
Id guid PK
Id_Customer guid FK
TFEnteranceDate datetime
TFEnteranceDatep nvarchar(10)
Without more information this could be a simple GROUP BY
SELECT TOP 1 TFEnteranceDate, Count(TFEnteranceDate) as Enterance
FROM Customer_Complex_LoginLogs
GROUP BY TFEnteranceDate
ORDER BY Count(TFEnteranceDate) DESC
EDIT: The day with the max number of TFEnteranceDate recorded