I want to do something like this:
select datediff('2010-01-21',(select date_of_birth from people));
and take as result the difference from each date_of_birth.
You can use datediff to get Difference in terms of day or specified format (either month, week year, days etc)
select datediff(DAY,'2010-01-21',date_of_birth)
from people
Related
I want to get the previous month date for specific dates in SQL. For example: 6.21.19 has a previous month date of 5.21.19.
I am just trying to get comps from this.
MONTH( curdate() ) -1
I need to return the previous month date.
Welcome to the board Arie. Judging from your question and responses, you need a range of dates and their prior month relations. The easiest way would be for all of the dates you need to look up to be in a table, then the answers provided so far would work. Since that doesn't appear to be the case, I'm guessing you are creating date ranges on the fly.
So lets assume you need exactly the data shown in your example, there are two parts to this, first you need to get a list of days that you want to look up, then you need to get the day in the prior month. There are lots of ways to get a sequence of days, but for simplicity I'll use a recursive CTE. Once I have the date range, I'll just select the dates and their prior month date as well.
with Date_CTE as (select cast('6/1/2019' as datetime) as repDate
union all
select dateadd(day, 1, repdate) as repDate
from Date_CTE
where repDate < '06/07/2019')
select repDate, dateadd(month, -1, repDate) as PriorDate
from Date_CTE
CTEs are helpful functions and you can get more details on them here, but it's worth noting there are many ways to do this. Hope this gets you pointed in the right direction.
SELECT yourDateColumn, yourDateColumn-interval 1 month as prevMonthDate
I need to get number of days between 2 dates, a given one and current date.
But in pure SQL, I mean without usign functions, it is possible?
For exaple
SELECT days (t.givenDate) - days (current date) FROM table t
Have you any idea?
Thaks a lot.
The built-in function is datediff(). The equivalent for the above is:
SELECT datediff(t.givenDate, curdate()) FROM table t;
Normally, givenDate would be in the past and you would want the arguments in the other order.
Say I have this .csv file which holds data that describes sales of a product. Now say I want a monthly breakdown of number of sales. I mean I wanna see how many orders were received in JAN2005, FEB2005...JAN2008, FEB2008...NOV2012, DEC2012.
Now one very simply way I can think of is count them one by one like this. (BTW I am using logparser to run my queries)
logparser -i:csv -o:csv "SELECT COUNT(*) AS NumberOfSales INTO 'C:\Users\blah.csv' FROM 'C:\User\whatever.csv' WHERE OrderReceiveddate LIKE '%JAN2005%'
My question is if there is a smarter way to do this. I mean, instead of changing the month again and again and running my query, can I write one query which can produce the result in one excel all at one.
Yes.
If you add a group by clause to the statement, then the sql will return a separate count for each unique value of the group by column.
So if you write:
SELECT OrderReceiveddate, COUNT(*) AS NumberOfSales INTO 'C:\Users\blah.csv'
FROM `'C:\User\whatever.csv' GROUP BY OrderReceiveddate`
you will get results like:
JAN2005 12
FEB2005 19
MAR2005 21
Assuming OrderReceiveDate is a date, you would format the date to have a year and month and then aggregate:
SELECT date_format(OrderReceiveddate, '%Y-%m') as YYYYMM, COUNT(*) AS NumberOfSales
INTO 'C:\Users\blah.csv'
FROM 'C:\User\whatever.csv'
WHERE OrderReceiveddate >= '2015-01-01'
GROUP BY date_format(OrderReceiveddate, '%Y-%m')
ORDER BY YYYYMM
You don't want to use like on a date column. like expects string arguments. Use date functions instead.
I need to display 2 columns. First column should have the month name. Second column should show me how many times something was released within each month. e.g:
Month number_of_releases
January 4
March 9
December 2
So far, I have this:
SELECT DISTINCT MONTHNAME(date) AS 'Month',
/*Here is where I need help!*/ AS 'number_of_releases'
FROM table_name;
Without knowing how you are calculating number_of_releases, it's hard to say for certain... but you probably want to group your table by monthname and use a suitable aggregate function to yield the number of releases.
For example, to obtain a count of the number of records within each month:
SELECT MONTHNAME(date) AS Month, COUNT(*) AS number_of_releases
FROM table_name
GROUP BY Month
If I have MySQL query like this, summing word frequencies per week:
SELECT
SUM(`city`),
SUM(`officers`),
SUM(`uk`),
SUM(`wednesday`),
DATE_FORMAT(`dateTime`, '%d/%m/%Y')
FROM myTable
WHERE dateTime BETWEEN '2011-09-28 18:00:00' AND '2011-10-29 18:59:00'
GROUP BY WEEK(dateTime)
The results given by MySQL take the first value of column dateTime, in this case 28/09/2011 which happens to be a Saturday.
Is it possible to adjust the query in MySQL to show the date upon which the week commences, even if there is no data available, so that for the above, 2011-09-28 would be replaced with 2011/09/26 instead? That is, the date of the start of the week, being a Monday. Or would it be better to adjust the dates programmatically after the query has run?
The dateTime column is in format 2011/10/02 12:05:00
It is possible to do it in SQL but it would be better to do it in your program code as it would be more efficient and easier. Also, while MySQL accepts your query, it doesn't quite make sense - you have DATE_FORMAT(dateTime, '%d/%m/%Y') in select's field list while you group by WEEK(dateTime). This means that the DB engine has to select random date from current group (week) for each row. Ie consider you have records for 27.09.2011, 28.09.2011 and 29.09.2011 - they all fall onto same week, so in the final resultset only one row is generated for those three records. Now which date out of those three should be picked for the DATE_FORMAT() call? Answer would be somewhat simpler if there is ORDER BY in the query but it still doesn't quite make sense to use fields/expressions in the field list which aren't in GROUP BY or which aren't aggregates. You should really return the week number in the select list (instead of DATE_FORMAT call) and then in your code calculate the start and end dates from it.