I have the following query:
SELECT count(*) as 'count'
FROM myTable
WHERE myDateTime >= DATE1 AND myDateTime < DATE2
-myDateTime is of type datetime (2013-01-30 08:48:13) in myTable.
-DATE1 and DATE2 should be created as datetime also so I could compare them, like this:
-DATE1 should to be created from year (eg 2013) and month (eg 01) parameters, and the day should always be 01 (the first day of the month)
-DATE2 should be same as DATE1 with an added month. (if DATE1 is 2013-01-01 00:00:00 then DATE2 should be 2013-02-01 00:00:00)
You can create the date as a number and then convert it to a date:
where myDateTime >= date(#year * 10000 + #month * 100 + 1) and
myDateTime < date_add(date(#year * 10000 + #month * 100 + 1), interval 1 month)
Related
i have this date 2021-08-19,
i want to select by month all my data from my table where dateC = ( extract month).
EXEMPLE QUERY
SELECT * FROM MYTABLE WHERE dateC= extract month "08" from(2021-08-19)
You can use:
where year(dateC) = year('2021-08-19') and
month(dateC) = month('2021-08-19')
If you just want the month regardless of year, then:
where month(dateC) = month('2021-08-19')
Or
where date_format(dateC, '%Y%m') = date_format('2021-08-19', '%Y%m')
Neither of these are index friendly. That requires a little more work. Let met call your date #date:
where dateC >= #date + interval (1 - day(#date)) day and
dateC < (#date + interval (1 - day(#date)) day) + interval 1 month
Note: all of the above work if there is a time component. If dateC is really a date with no time component, then:
where dateC > last_day(#date - interval 1 month) and
dateC <= last_day(#date)
I have an insurance policies table like this:
+-------------------------------------------------------------+
| id | cancellation_val | cancellation_interval | expire_date |
+-------------------------------------------------------------+
| 1 | 30 | day | 2019-06-09 |
| 2 | 2 | month | 2019-12-01 |
+-------------------------------------------------------------+
I need to get the ids of the policies that are going to expire based on cancellation, from today and within 4 months, calculating the last day of the month, like this pseudo-code:
'today' <= LAST_DAY( expire_date - cancellation_val/interval ) < 'today + 4 months'
Being not a pro I think I should use JOINs but I don't know how, after days of trying the only thing I achieved was this:
SELECT LAST_DAY(
DATE_FORMAT(
STR_TO_DATE(
(SELECT CASE cancellation_interval
WHEN "day" THEN date_sub(expire_date, INTERVAL cancellation_val DAY)
WHEN "month" THEN date_sub(data_scadenzaexpire_date, INTERVAL cancellation_val MONTH)
END
AS newDate
FROM insurance WHERE id=2
), '%Y-%m-%d'
), '%Y-%m-%d'
)
)
This is working but I don't need the "WHERE id=2" clause (because I need to process ALL rows of the table), and if I remove it I got error "subquery returns more than 1 row".
So how I can proceed? And using the result to stay between 'today' AND 'today + 4 months' ?
I think with some kind of JOIN I could do it in a easier way but I don't know how.
Thank you all
The problem is the structure of the query, not the LAST_DAY function.
We want to return the id values of rows that meet some condition. So the query would be of the form:
SELECT t.id
, ...
FROM insurance t
WHERE ...
HAVING ...
Introducing another SELECT keyword basically introduces a subquery. There are restrictions on subqueries... in the SELECT list, a subquery can return a single column and (at most) a single row.
So let's ditch that extra SELECT keyword.
We can derive the newdate as an expression of the SELECT list, and then we can reference that derived column in the HAVING clause. The spec said we wanted to return the id value, so we include that in the SELECT list. We don't have to return any other columns, but for testing/debugging, it can be useful to return the values that were used to derive the newdate column.
Something like this:
SELECT t.id
, LAST_DAY(
CASE t.cancellation_interval
WHEN 'day' THEN t.expire_date - INTERVAL t.cancellation_val DAY
WHEN 'month' THEN t.expire_date - INTERVAL t.cancellation_val MONTH
ELSE t.expire_date
END
) AS newdate
, t.expire_date
, t.cancellation_interval
, t.cancellation_val
FROM insurance t
HAVING newdate >= DATE(NOW())
AND newdate <= DATE(NOW()) + INTERVAL 4 MONTH
ORDER
BY newdate ASC
We don't have to include the newdate in the SELECT list; we could just replace occurrences of newdate in the HAVING clause with the expression.
We could also use an inline view to "hide" the derivation of the newdate column
SELECT v.id
, v.newdate
FROM ( SELECT t.id
, LAST_DAY(
CASE t.cancellation_interval
WHEN 'day' THEN t.expire_date - INTERVAL t.cancellation_val DAY
WHEN 'month' THEN t.expire_date - INTERVAL t.cancellation_val MONTH
ELSE t.expire_date
END
) AS newdate
FROM insurance t
) v
WHERE v.newdate >= DATE(NOW())
AND v.newdate <= DATE(NOW()) + INTERVAL 4 MONTH
ORDER
BY v.newdate ASC
check this query: remove the HAVING Line to see all rows
SELECT
IF(cancellation_interval = 'day',
i.expire_date - INTERVAL i.`cancellation_val` DAY,
i.expire_date - INTERVAL i.`cancellation_val` MONTH
) as cancellation_day,
i.*
FROM `insurance` i
HAVING cancellation_day < NOW() + INTERVAL 4 MONTH;
SAMPLES
MariaDB [test]> SELECT IF(cancellation_interval = 'day', i.expire_date - INTERVAL i.`cancellation_val` DAY, i.expire_date - INTERVAL i.`cancellation_val` MONTH ) as cancellation_day, i.* FROM `insurance` i HAVING cancellation_day < NOW() + INTERVAL 4 MONTH;
+------------------+----+------------------+-----------------------+-------------+
| cancellation_day | id | cancellation_val | cancellation_interval | expire_date |
+------------------+----+------------------+-----------------------+-------------+
| 2019-05-10 | 1 | 30 | day | 2019-06-09 |
+------------------+----+------------------+-----------------------+-------------+
1 row in set (0.001 sec)
When you use a SELECT query as an expression, it can only return one row.
If you want to process all the rows, you need to call LAST_DAY() inside the query, not on the result.
SELECT *
FROM insurance
WHERE CURDATE() <= LAST_DAY(
expire_date - IF(cancellation_interval = 'day',
INTERVAL cancellation_val DAY,
INTERVAL cancellation_val MONTH))
AND LAST_DAY(expire_date - IF(cancellation_interval = 'day',
INTERVAL cancellation_val DAY,
INTERVAL cancellation_val MONTH)) < CURDATE + INTERVAL 4 MONTH
I am selecting all records between NOW() and specific X day interval and came across this odd behavior that I don't understand.
I am checking 24 hours into the future and 24 hours into the past:
select * from table where date between NOW() and NOW() + 1 interval day; //works
select * from table where date between NOW() and NOW() - 1 interval day; //no records
But if I reverse the between call:
select * from table where date between NOW() + 1 interval day AND NOW(); //no records
select * from table where date between NOW() - 1 interval day AND NOW(); //works
Why does one call into the future work, but the same call into the past not work?...and if I reverse between parameters, the opposite behavior happens - does not work 24 hours into the future but does work 24 hours into the past.
======================
Adding #TimBiegeleisen explanation below here written out:
date = '2018-05-30' ;
select * from table where date between NOW() and NOW() + 1 interval day;
= date >= '2018-05-30' AND 'date <= 2018-05-31'; //true
select * from table where date between NOW() and NOW() - 1 interval day; records
= date >= '2018-05-30' AND 'date <= 2018-05-29'; //false
AND
select * from table where date between NOW() + 1 interval day AND NOW();
= date >= '2018-05-31' AND date <= '2018-05-30' //false
select * from table where date between NOW() - 1 interval day AND NOW();
= date >= '2018-05-29' and date <= '2018-05-30'; //true
The BETWEEN operator is interpreted a certain way:
WHERE date BETWEEN a AND b
means this:
WHERE date >= a AND date <= b
So the following two queries are equivalent:
select * from table where date between NOW() and NOW() - interval 1 day;
select * from table where date >= NOW() and date <= NOW() - interval 1 day;
Hopefully you can see that in your second query the WHERE condition can never be true, because a date cannot simutaneously be greater than or equal to now and less than now minus one at the same time.
simply put,
For SQL:
WHERE x between a and b
meaning
x >= a
and
x <= b
therefore, we have a <= x <= b or a <= b
PS: it's just about math :)
I have a list of periods during a year, and they are the same every year. You can think of it as a Season. They have a startDate and a endDate.
Because there can be Seasons that leap each other, what I need to to is query all the matching Seasons given a date, no matter what year.
As an example:
Season1: from 1st of January to 10th of January
Season2: from 6th of January to 8th of January
Season3: from 11th of January to 20th of January
Given the date 7th of January, I'd need to retrieve the Season1 and Season2.
I've tried converting all dates to the same year, but It doesn't work when the Start Date of a season in "later" than the End Date (for example, there's a period starting on November and ending of February).
Thanks in advance for the help.
Edit, sample data:
StartDate EndDate SeasonId
2000-08-01 2000-08-31 4
2000-12-29 2000-01-02 3
2000-06-01 2000-07-30 3
2000-09-01 2000-09-30 3
2000-01-06 2000-01-08 3
2000-04-07 2000-04-17 3
2000-04-28 2000-05-01 3
2000-06-02 2000-06-05 3
2000-06-23 2000-06-25 3
2000-09-08 2000-09-11 3
2000-09-22 2000-09-25 3
2000-10-12 2000-10-15 3
2000-11-01 2000-11-05 3
2000-12-01 2000-12-10 3
2000-12-22 2000-12-26 3
2000-03-01 2000-05-31 2
2000-10-01 2000-10-31 2
2000-11-01 2000-02-28 1
And I'd need, for example, the season for the date 2000-02-08, and retrieve seasonId = 1, or the date 2000-10-13and retrive seasonId = 3, seasonId = 2
I would do it in 2 'options': (the following SQL assumes you already got rid of the year in the table, and left only month-date format. )
select ... from seasons s where
(s.startDate <= s.endDate and s.startDate <= #mydate and s.endDate >= #mydate) or
(s.startDate > s.endDate and s.startDate >= #mydate and s.endDate <= #mydate)
You could query like this for the Season1:
select * from myTable where (month(myDate) = 1 and DAY(myDate) between 1 and 10)
If you have a season in more than one month, like start date January 20th, and finish date Febrery 10th, you could query this way:
select * from myTable where (month(myDate) = 1 and DAY(myDate) >= 20) or (month(myDate) = 2 and DAY(myDate) <= 10)
UPDATED WITH YOUR UPDATE
It is a little bit tricky, but it should work...
select * from seasons_table
where cast(cast(day(myDate) as char) + '/' + cast(month(myDate) as char) + '/' + '2000' as date) between
cast(cast(day(StartDate) as char) + '/' + cast(month(StartDate) as char) + '/' + '2000' as date) and
cast(cast(day(EndDate) as char) + '/' + cast(month(EndDate) as char) + '/' + '2000' as date)
given tblSeason with columns Id, startdate, enddate and your date as #myDate you would query as
Select Id From tblSeason WHERE #myDate BETWEEN startdate AND enddate
would give list of Id's of the seasons that match.
if you can't work from that, please give more information in your examples as to the structure you are querying and the expected outcome.
*Edit to ignore the year part you could do similar to
Declare #myDate datetime = '2016-10-13'
SELECT [StartDate]
,[EndDate]
,[SeasonId]
FROM [dbo].[Table_1]
where DATEPART(dy, #myDate) >= DATEPART(dy,StartDate)
AND (DATEPART(dy,#myDate) =< DATEPART(dy,EndDate) OR DATEPART(dy,StartDate) > DATEPART(dy,EndDate))
Why are you including the year in the table? That seems strange.
In any case, you only care about the MM-DD format, so use date_format() to convert the values to strings:
select t.*
from t
where (start_date <= end_date and
date_format(#date, '%m-%d') >= date_format(start_date, '%m-%d') and
date_format(#date, '%m-%d') <= date_format(end_date, '%m-%d')
) or
(start_date > end_date and
date_format(#date, '%m-%d') <= date_format(start_date, '%m-%d') and
date_format(#date, '%m-%d') >= date_format(end_date, '%m-%d')
);
The strings are fine for comparison, because you are only looking at the month and day components of the date.
Given the nature of your problem, I would recommend that you store start_date and end_date in a non-date format, such as MM-DD.
Is it possible to query for all dates in the future that are an increment of x days?
i.e.
SELECT *
FROM bookings
WHERE date >= CURDATE()
AND
(
date = CURDATE() + INTERVAL 6 DAY
OR date = CURDATE() + INTERVAL 12 DAY
OR date = CURDATE() + INTERVAL 18 DAY
etc.
)
Something like:
SELECT
*
FROM table
WHERE
date >= CURDATE()
AND
DATEDIFF(CURDATE(), date) % 6 = 0
Datediff returns the number of days difference, and % 6 says return the remainder when divided by six.
Yes.
Your logic is flawed, though. You probably meant
SELECT *
FROM table
WHERE
date = CURDATE() + INTERVAL 6 DAY
OR date = CURDATE() + INTERVAL 12 DAY
OR date = CURDATE() + INTERVAL 18 DAY
And don't use table names like "table" and field names like "date" (i.e. reserved words).