Can anyone please help me. I am trying to calculate the difference between record entry 1 and record entry 2 and so and so on date and time in two separate records
I want to add another row to calculate the difference Between Entry 1 and Entry 2. I know that if i did have a check in and check out then i could just subtract time out from time in and its sorted. But have never tried between records
Update And the Code that i'm using is:
SELECT USERINFO.name, CHECKINOUT.CHECKTIME
FROM CHECKINOUT, USERINFO
WHERE (((USERINFO.name)=[Enter Name]))
ORDER BY CHECKINOUT.CHECKTIME DESC;
Select
name,
DateValue(CHECKTIME) AS Date,
TimeValue(CHECKTIME) AS Time
From CHECKOUT
It could be:
Select *,
(CheckTime - (Select Top 1 CheckTime
From [Employee Check] As T
Where T.Name = [Employee Check].Name
And T.CheckTime < [Employee Check].CheckTime
Order By T.CheckTime Desc)) As CheckTimeDiff
From [Employee Check]
Related
I currently have an employee logging sql table that has 3 columns
fromState: String,
toState: String,
timestamp: DateTime
fromState is either In or Out. In means employee came in and Out means employee went out. Each row can only transition from In to Out or Out to In.
I'd like to generate a temporary table in sql to keep track during a given hour (hour by hour), how many employees are there in the company. Aka, resulting table has columns HourBucket, NumEmployees.
In non-SQL code I can do this by initializing the numEmployees as 0 and go through the table row by row (sorted by timestamp) and add (employee came in) or subtract (went out) to numEmployees (bucketed by timestamp hour).
I'm clueless as how to do this in SQL. Any clues?
Use a COUNT ... GROUP BY query. Can't see what you're using toState from your description though! Also, assuming you have an employeeID field.
E.g.
SELECT fromState AS 'Status', COUNT(*) AS 'Number'
FROM StaffinBuildingTable
INNER JOIN (SELECT employeeID AS 'empID', MAX(timestamp) AS 'latest' FROM StaffinBuildingTable GROUP BY employeeID) AS LastEntry ON StaffinBuildingTable.employeeID = LastEntry.empID
GROUP BY fromState
The LastEntry subquery will produce a list of employeeIDs limited to the last timestamp for each employee.
The INNER JOIN will limit the main table to just the employeeIDs that match both sides.
The outer GROUP BY produces the count.
SELECT HOUR(SBT.timestamp) AS 'Hour', SBT.fromState AS 'Status', COUNT(*) AS 'Number'
FROM StaffinBuildingTable AS SBT
INNER JOIN (
SELECT SBIJ.employeeID AS 'empID', MAX(timestamp) AS 'latest'
FROM StaffinBuildingTable AS SBIJ
WHERE DATE(SBIJ.timestamp) = CURDATE()
GROUP BY SBIJ.employeeID) AS LastEntry ON SBT.employeeID = LastEntry.empID
GROUP BY SBT.fromState, HOUR(SBT.timestamp)
Replace CURDATE() with whatever date you are interested in.
Note this is non-optimal as it calculates the HOUR twice - once for the data and once for the group.
Again you are using the INNER JOIN to limit the number of returned row, this time to the last timestamp on a given day.
To me your description of the FromState and ToState seem the wrong way round, I'd expect to doing this based on the ToState. But assuming I'm wrong on that the following should point you in the right direction:
First, I create a "Numbers" table containing 24 rows one for each hour of the day:
create table tblHours
(Number int);
insert into tblHours values
(0),(1),(2),(3),(4),(5),(6),(7),
(8),(9),(10),(11),(12),(13),(14),(15),
(16),(17),(18),(19),(20),(21),(22),(23);
Then for each date in your employee logging table, I create a row in another new table to contain your counts:
create table tblDailyHours
(
HourBucket datetime,
NumEmployees int
);
insert into tblDailyHours (HourBucket, NumEmployees)
select distinct
date_add(date(t.timeStamp), interval h.Number HOUR) as HourBucket,
0 as NumEmployees
from
tblEmployeeLogging t
CROSS JOIN tblHours h;
Then I update this table to contain all the relevant counts:
update tblDailyHours h
join
(select
h2.HourBucket,
sum(case when el.fromState = 'In' then 1 else -1 end) as cnt
from
tblDailyHours h2
join tblEmployeeLogging el on
h2.HourBucket >= el.timeStamp
group by h2.HourBucket
) cnt ON
h.HourBucket = cnt.HourBucket
set NumEmployees = cnt.cnt;
You can now retrieve the counts with
select *
from tblDailyHours
order by HourBucket;
The counts give the number on site at each of the times displayed, if you want during the hour in question, we'd need to tweak this a little.
There is a working version of this code (using not very realistic data in the logging table) here: rextester.com/DYOR23344
Original Answer (Based on a single over all count)
If you're happy to search over all rows, and want the current "head count" you can use this:
select
sum(case when t.FromState = 'In' then 1 else -1) as Heads
from
MyTable t
But if you know that there will always be no-one there at midnight, you can add a where clause to prevent it looking at more rows than it needs to:
where
date(t.timestamp) = curdate()
Again, on the assumption that the head count reaches zero at midnight, you can generalise that method to get a headcount at any time as follows:
where
date(t.timestamp) = "CENSUS DATE" AND
t.timestamp <= "CENSUS DATETIME"
Obviously you'd need to replace my quoted strings with code which returned the date and datetime of interest. If the headcount doesn't return to zero at midnight, you can achieve the same by removing the first line of the where clause.
I am using the Graph Reports for the select below. The MySQL database only has the active records in the database, so if no records are in the database from X hours till Y hours that select does not return anything. So in my case, I need that select return Paypal zero values as well even the no activity was in the database. And I do not understand how to use the UNION function or re-create select in order to get the zero values if nothing was recorded in the database in time interval. Could you please help?
select STR_TO_DATE ( DATE_FORMAT(`acctstarttime`,'%y-%m-%d %H'),'%y-%m-%d %H')
as '#date', count(*) as `Active Paid Accounts`
from radacct_history where `paymentmethod` = 'PayPal'
group by DATE_FORMAT(`#date`,'%y-%m-%d %H')
When I run the select the output is:
Current Output
But I need if there are no values between 2016-07-27 07:00:00 and 2016-07-28 11:00:00, then in every hour it should show zero active accounts Like that:
Needed output with no values every hour
I have created such select below , but it not put to every hour the zero value like i need. showing the big gap between the 12 Sep and 13 Sep anyway, but there should be the zero values every hour
(select STR_TO_DATE ( DATE_FORMAT(acctstarttime,'%y-%m-%d %H'),'%y-%m-%d %H')
as '#date', count(paymentmethod) as Active Paid Accounts
from radacct_history where paymentmethod <> 'PayPal'
group by DATE_FORMAT(#date,'%y-%m-%d %H'))
union ALL
(select STR_TO_DATE ( DATE_FORMAT(acctstarttime,'%y-%m-%d %H'),'%y-%m-%d %H')
as '#date', 0 as Active Paid Accounts
from radacct_history where paymentmethod <> 'PayPal'
group by DATE_FORMAT(#date,'%y-%m-%d %H')) ;
I guess, you want to return 0 if there is no matching rows in MySQL. Here is an example:
(SELECT Col1,Col2,Col3 FROM ExampleTable WHERE ID='1234')
UNION (SELECT 'Def Val' AS Col1,'none' AS Col2,'' AS Col3) LIMIT 1;
Updated the post: You are trying to retrieve data that aren't present in the table, I guess in reference to the output provided. So in this case, you have to maintain a date table to show the date that aren't in the table. Please refer to this and it's little bit tricky - SQL query that returns all dates not used in a table
You need an artificial table with all necessary time intervals. E.g. if you need daily data create a table and add all day dates e.g. start from 1970 till 2100.
Then you can use the table and LEFT JOIN your radacct_history. So for each desired interval you will have group item (group by should be based on the intervals table.
I have a table "Report" with relevant columns "Date", "Doctor". Each doctor appears several times throughout the table. The following code is what I have at current:
SET #variable = (SELECT Date FROM Report WHERE Doctor='DocName' ORDER BY Date DESC LIMIT 1)
SELECT DATEDIFF(CURDATE(),#variable) AS DiffDate
This gives me the DATEDIFF for one doctor, without name. Is there any way to loop through the table, find the last row/date for each doctor, then perform a DATEDIFF on each individual doctor outputting a list of doctors with their DATEDIFFs (against current date) next to them?
Thanks in advance!
you can use group by to get only 1 row per doctor and max to select latest date:
select `Doctor`, DATEDIFF(CURDATE(),max(`Date`))
from `Report`
group by `Doctor`
I have some data which I want to retrieve, but I want to have it grouped by a specific number of seconds. For example if my table looks like this:
| id | user | pass | created |
The created column is INT and holds a timestamp (number of seconds from 1970).
I would want the number of users that are created between last month and the current date, but show them grouped by let's say 7*24*3600 (a week). So if in the range there are 1000 new users, have them show up how many registered each week (100 the first week, 450 the second, 50 the third and 400 the 4th week -- something like this).
I've tried grouping the results by created / 7*24*3600, but that's not working.
How should my query look like?
You need to use integer division div otherwise the result will turn into a real and none of the weeks will resolve to the same value.
SELECT
(created div (7*24*60*60)) as weeknumber
, count(*) as NewUserCount
FROM users
WHERE weeknumber > 1
GROUP BY weeknumber
See: http://dev.mysql.com/doc/refman/5.0/en/arithmetic-functions.html
You've got to keep the integer part only of that division. You can do it with the floor() function.
Have you tried select floor(created/604800) as week_no, count(*) from users group by floor(created/604800) ?
I assume you've got the "select users created in the last month" part sorted out.
Okay here are the possible options you may try:
GROUP BY DAY
select count(*), DATE_FORMAT(created_at,"%Y-%m-%d") as created_day FROM widgets GROUP BY created_day
GROUP BY MONTH
select count(*), DATE_FORMAT(created_at,"%Y-%m") as created_month FROM widgets GROUP BY created_month
GROUP BY YEAR
select count(*), DATE_FORMAT(created_at,"%Y") as created_year FROM widgets GROUP BY created_year
Assume you have a table with a stock time series on a daily basis.
Now you need to filter one data point per week, because you need weekly data for some analysis. You don't to have weekly averages, since this would leave much of the variation out.
This would be my initial approach, but it's not clear which of the data points falling in a given week is selected.
SELECT date, price from stock_series
GROUP BY WEEK(date)
1 How do I make sure it's always the first data point existing for a given week that gets picked?
EDIT:
2 If the above query stayed the way it is - which data point gets chosen every week? What's the MySQL logic in this case? Or is it just unpredictible?
If you want to have a better control over it, you could try using a subquery :
SELECT date,price
FROM stock_series
WHERE date IN
(
SELECT MIN(inner.date)
FROM stock_series inner
GROUP BY WEEK(inner.date)
) GROUP BY date
I've added GROUP BY date in the main query because you probably have more than one entry per day, otherwise it could be ommited.
EDIT:
or try joining with it:
SELECT date,price
FROM stock_series
JOIN
(
SELECT MIN(date) AS innerdate
FROM stock_series
GROUP BY WEEK(date)
) inner ON date=innerdate;
You can order by date ascending, which should give you just the first result of the WEEK() group.
SELECT date,price from stock_series
GROUP BY WEEK(date)
ORDER BY date