I have a table
---------+-----------+------------------+--------------------+
| id | user_id | start_date_time | end_date_time |
+---------+---------+-------------------+--------------------+
| 1 | 11 |2019-11-17 20:10:00|2019-11-17 21:05:00 |
| 2 | 11 |2019-11-17 20:18:00|2019-11-17 20:35:00 |
| 3 | 11 |2019-11-17 20:32:00|2019-11-17 21:18:00 |
| 4 | 11 |2019-11-17 20:40:00|2019-11-17 20:50:00 |
| 5 | 11 |2019-11-17 20:45:00|2019-11-17 21:20:00 |
| | | | |
+---------+---------+-------------------+--------------------+
Scenario 1 - If i query for all greater than '2019-11-17 20:18:00' I need to get all records.
Scenario 2 - If i query for all possible dates greater or equals '2019-11-17 21:18:00' It should return record 3 and 5.
For any given time it should look for Start_date_time and End_date_time where given time should be considered as start time and it should look for appropriate end_date_time and output the result.
In a nut shell input time should be taken as starting range and it should look for End_date_time and give me all values between.
How can i accomplish this?
i tried the following ways on db-fiddle https://www.db-fiddle.com/f/bPk1CYioL6cVasStZKzQ4j/7
if i query all records from a given time eg(2019-11-17 20:18:00) the input should be taken as a start datetime of range and look for the most greatest end_date_time and give me the records between them. Example 2019-11-17 20:18:00 this input takes range between input as val1 of range 2019-11-17 20:18:00 to 2019-11-17 21:20:00 the highest end date and give me all records between. And if i query with input 2019-11-17 21:05:00 this should take start range val1 as 2019-11-17 21:05:00 and 2019-11-17 21:20:00 output 1,3,5 records.
The requirement (with the results that you expect) is as simple as that:
select *
from times
where ? <= end_date_time
Replace ? with the datetime that you want to query.
See the demo.
Related
I'm creating a database (in MySQL) with a table of measurements. For each measurement I want to store the DateTime it came in. For showing plots within an app for different intervals (measurements of the day/week/month/year) I want sample the data points I have, so I can return e. g. 30 data points for the whole year as well as for the day/hour. This is the same as done with stock price graphs:
stock price plot for 1 day
vs
stock price plot for 1 month
As you can see, the amount of data points is the same in both pictures.
So how can I select x entries within a timespan in MySQL via SQL?
My data looks like this:
+====+====================+=============+==========+
| id | datetime | temperature | humidity |
+====+====================+=============+==========+
| 1 | 1-15-2016 00:30:00 | 20 | 40 |
+----+--------------------+-------------+----------+
| 2 | 1-15-2016 00:35:00 | 19 | 41 |
+----+--------------------+-------------+----------+
| 3 | 1-15-2016 00:40:00 | 20 | 40 |
+----+--------------------+-------------+----------+
| 4 | 1-15-2016 00:45:00 | 20 | 42 |
+----+--------------------+-------------+----------+
| 5 | 1-15-2016 00:50:00 | 21 | 42 |
+----+--------------------+-------------+----------+
| 6 | 1-15-2016 00:55:00 | 20 | 43 |
+----+--------------------+-------------+----------+
| 7 | 1-15-2016 01:00:00 | 21 | 43 |
+====+====================+=============+==========+
Let's say, I always want two data points (in reality a lot more). So for the last half hour I want the database to return data point 1 and 4, for the last ten minutes I want it to return 6 and 7.
Thanks for helping!
PS: I'm sorry for any errors in my English
OK, assuming a very simple systematic approach, you can get the first and last entry for any defined period:
select *
from table
where mydatetime =
(select
max(mydatetime)
from table
where mydatetime between '2017-03-01' and '2017-03-15'
)
OR mydatetime =
(select
min(mydatetime)
from table
where mydatetime between '2017-03-01' and '2017-03-15'
)
I believe your answer can be found at the following location:
https://stackoverflow.com/a/1891796/7176046
If you are looking to filter out any items not within your date/time your query would use:
Select * from table where Date/Time is (What you want to sort by)
I have a "readings" table with columns
timestamp as DateTime
channel_id as integer
value as Decimal
test_id as integer
Now i want to filter rows by test_id which anybody can do. Then in the result number of rows is too much. Suppose if i use channel number 2,3 and 5 for my test_id 17 and if I log data for every second then there are 10k rows.
When I plot the graph there where will so many data that the graph lines are not visible clearly, so to make them visible I need to filter out some rows.
I need some help in filtering of rows with time difference between the two records should be few seconds lets say 10 seconds. In this the data is not consecutive.
Any help will be greatly appreciated.
The sample data will be as follows:
24-05-2016 08:00:55 am | 2 | 10.23 | 17
24-05-2016 08:00:55 am | 3 | 100.23 | 17
24-05-2016 08:00:55 am | 5 | 12.23 | 17
24-05-2016 08:00:56 am | 2 | 09.23 | 17
24-05-2016 08:00:56 am | 3 | 12.23 | 17
24-05-2016 08:00:56 am | 5 | 11.23 | 17
24-05-2016 08:00:57 am | 2 | 09.23 | 17
24-05-2016 08:00:57 am | 3 | 01.23 | 17
24-05-2016 08:00:57 am | 5 | 11.23 | 17
24-05-2016 08:00:58 am | 2 | 09.23 | 17
24-05-2016 08:00:58 am | 3 | 01.23 | 17
24-05-2016 08:00:58 am | 5 | 11.23 | 17
Instead of filtering you can aggregate data for the period using GROUP BY functionality. For example, 10-second periods can be calculated from the timestamps using this formula:
ROUND(UNIX_TIMESTAMP(timestamp)/10)
So, this formula can be added to GROUP BY query, so query can aggregate data on that period:
SELECT test_id,channel_id,ROUND(UNIX_TIMESTAMP(timestamp)/10),
min(value), max(value), avg(value),count(*)
FROM your_table
WHERE some_conditions
GROPU BY test_id,channel_id,ROUND(UNIX_TIMESTAMP(timestamp)/10)
So I am currently writing an SSRS report which I want to calculate lead time based on an arbitrary number deliveries.
I have my query in SSRS but now I would like to filter it to show the last 5 deliveries. Usually I would use a Top N for filtering but SSRS rightly complains that the number 5 is not a date.
How do you filter the last five latest dates without knowing the exact dates of the records you are returning?
Dataset is as follows (lead time is a calculation of order date less delivery date)
Order | Del_Date | Lead_Time
------|------------|-----------
00001 | 2015-05-01 | 20
00002 | 2015-01-08 | 21
00003 | 2015-02-05 | 22
00004 | 2015-03-11 | 26
00005 | 2015-01-21 | 8
00006 | 2015-04-12 | 12
00007 | 2015-03-02 | 12
00008 | 2015-02-01 | 12
The query should return
Order | Del_Date | Lead_Time
------|------------|-----------
00001 | 2015-05-01 | 20
00003 | 2015-02-05 | 22
00004 | 2015-03-11 | 26
00006 | 2015-04-12 | 12
00007 | 2015-03-02 | 12
Thanks,
Can you try this:
SELECT TOP 5
Order,
Del_Date,
Lead_Time
FROM
[TABLE]
...
ORDER BY
Del_Date DESC
You can modify the data set definition as Matteo suggested or apply a filter to the object displaying the data. Based on your question I am assuming you want to use the object displaying the data to filter your results.
To get the top 5 dates change the data object sorting to the date field and order "Z to A". Then under filters select the date field you want in the expression box. Set the operator to "Top N" and set the value to "=5".
If tablix filter complains about top 5, then you can bring row_number (ranking) to tablix and filter it by ranking <=5
I have an event system and for my repeat events I am using a cron like system.
Repeat Event:
+----+----------+--------------+
| id | event_id | repeat_value |
+----+----------+--------------+
| 1 | 11 | *_*_* |
| 2 | 12 | *_*_2 |
| 3 | 13 | *_*_4/2 |
| 4 | 14 | 23_*_* |
| 5 | 15 | 30_05_* |
+----+----------+--------------+
NOTE: The cron value is day_month_day of week
Event:
+----+------------------------+---------------------+---------------------+
| id | name | start_date_time | end_date_time |
+----+------------------------+---------------------+---------------------+
| 11 | Repeat daily | 2014-04-30 12:00:00 | 2014-04-30 12:15:00 |
| 12 | Repeat weekly | 2014-05-06 12:00:00 | 2014-05-06 13:00:00 |
| 13 | Repeat every two weeks | 2014-05-08 12:45:00 | 2014-05-08 13:45:00 |
| 14 | Repeat monthly | 2014-05-23 15:15:00 | 2014-05-23 16:00:00 |
| 15 | Repeat yearly | 2014-05-30 07:30:00 | 2014-05-30 10:15:00 |
+----+------------------------+---------------------+---------------------+
Anyway I have a query to select the events:
SELECT *
FROM RepeatEvent
JOIN `Event`
ON `Event`.`id` = `RepeatEvent`.`event_id`
That produces:
+----+----------+--------------+----+------------------------+---------------------+---------------------+
| id | event_id | repeat_value | id | name | start_date_time | end_date_time |
+----+----------+--------------+----+------------------------+---------------------+---------------------+
| 1 | 11 | *_*_* | 11 | Repeat daily | 2014-04-30 12:00:00 | 2014-04-30 12:15:00 |
| 2 | 12 | *_*_2 | 12 | Repeat weekly | 2014-05-06 12:00:00 | 2014-05-06 13:00:00 |
| 3 | 13 | *_*_4/2 | 13 | Repeat every two weeks | 2014-05-08 12:45:00 | 2014-05-08 13:45:00 |
| 4 | 14 | 23_*_* | 14 | Repeat monthly | 2014-05-23 15:15:00 | 2014-05-23 16:00:00 |
| 5 | 15 | 30_05_* | 15 | Repeat yearly | 2014-05-30 07:30:00 | 2014-05-30 10:15:00 |
+----+----------+--------------+----+------------------------+---------------------+---------------------+
However, I want to select events within a month. I will only have certain conditions: daily, weekly, every two weeks, month and yearly.
I want to put in my where clause a way to divide the string of the repeat value and if it fits any of the following conditions to show it as a result (repeatEvent is row that is being interrogated, search is the date being looked for):
array(3) = string_divide(repeat_value, '_')
daily = array(0)
monthy = array(1)
dayOfWeek = array(2)
if(daily == '*' && month == '*' && dayOfWeek == '*') //returns all the daily events as they will happen
return repeatEvent
if(if(daily == '*' && month == '*' && dayOfWeek == search.dayOfWeek) //returns all the events on specific day
return repeatEvent
if(daily == search.date && month == '*' && dayOfWeek == '*') //returns all the daily events as they will happen
return repeatEvent
if (contains(dayOfWeek, '/'))
array(2) = string_divide(dayOfWeek,'/')
specificDayOfWeek = array(0);
if(specificDayOfWeek == repeatEvent.start_date.dayNumber)
if(timestampOf(search.timestamp)-timestampOf(repeatEvent.start_date)/604800 == (0 OR EVEN)
return repeatEvent
if(daily == search.date && month == search.month && dayOfWeek == '*') //returns a single yearly event (shouldn't often crop up)
return repeatEvent
//everything else is either an unknown format of repeat_value or not an event on this day
To summarise I want to run a query in which the repeat value is split in the where clause and I can interrogate the split items. I have looked at cursors but the internet seems to advise against them.
I could process the results of selecting all the repeat events in PHP, however, I imagine this being very slow.
Here is what I would like to see if looking at the month of April:
+----------+--------------+----+------------------------+---------------------+---------------------+
| event_id | repeat_value | id | name | start_date_time | end_date_time |
+----------+--------------+----+------------------------+---------------------+---------------------+
| 11 | *_*_* | 11 | Repeat daily | 2014-04-30 12:00:00 | 2014-04-30 12:15:00 |
+----------+--------------+----+------------------------+---------------------+---------------------+
Here is what I would like to see if looking at the month of May
+----------+--------------+----+------------------------+---------------------+---------------------+
| event_id | repeat_value | id | name | start_date_time | end_date_time |
+----------+--------------+----+------------------------+---------------------+---------------------+
| 11 | *_*_* | 11 | Repeat daily | 2014-04-30 12:00:00 | 2014-04-30 12:15:00 |
| 12 | *_*_2 | 12 | Repeat weekly | 2014-05-06 12:00:00 | 2014-05-06 13:00:00 |
| 13 | *_*_4/2 | 13 | Repeat every two weeks | 2014-05-08 12:45:00 | 2014-05-08 13:45:00 |
| 14 | 23_*_* | 14 | Repeat monthly | 2014-05-23 15:15:00 | 2014-05-23 16:00:00 |
| 15 | 30_05_* | 15 | Repeat yearly | 2014-05-30 07:30:00 | 2014-05-30 10:15:00 |
+----------+--------------+----+------------------------+---------------------+---------------------+
Here is what I would like to see if looking at the month of June
+----------+--------------+----+------------------------+---------------------+---------------------+
| event_id | repeat_value | id | name | start_date_time | end_date_time |
+----------+--------------+----+------------------------+---------------------+---------------------+
| 11 | *_*_* | 11 | Repeat daily | 2014-04-30 12:00:00 | 2014-04-30 12:15:00 |
| 12 | *_*_2 | 12 | Repeat weekly | 2014-05-06 12:00:00 | 2014-05-06 13:00:00 |
| 13 | *_*_4/2 | 13 | Repeat every two weeks | 2014-05-08 12:45:00 | 2014-05-08 13:45:00 |
| 14 | 23_*_* | 14 | Repeat monthly | 2014-05-23 15:15:00 | 2014-05-23 16:00:00 |
+----------+--------------+----+------------------------+---------------------+---------------------+
You could put a bandaid on this, but no one would be doing you any favors to tell you that that is the answer.
If your MySQL database can be changed I would strongly advise you to split your current column with underscores day_month_day of year to three separate columns, day, month, and day_of_year. I would also advise you to change your format to be INT rather than VARCHAR. This will make it faster and MUCH easier to search and parse, because it is designed in a way that doesn't need to be translated into computer language through complicated programs... It is most of the way there already.
Here's why:
Reason 1: Your Table is not Optimized
Your table is not optimized and will be slowed regardless of what you choose to do at this stage. SQL is not built to have multiple values in one column. The entire point of an SQL database is to split values into different columns and rows.
The advantage to normalizing this table is that it will be far quicker to search it, and you will be able to build queries in MySQL. Take a look at Normalization. It is a complicated concept, but once you get it you will avoid creating messy and complicated programs.
Reason 2: Your Table could be tweaked slightly to harness the power of computer date/time functions.
Computers follow time based on Unix Epoch Time. It counts seconds and is always running in your computer. In fact, computers have been counting this since, as the name implies, the first Unix computer was ever switched on. Further, each computer and computer based program/system, has built in, quick date and time functions. MySQL is no different.
I would also recommend also storing all of these as integers. repeat_doy (day of year) can easily be a smallint or at least a standard int, and instead of putting a month and day, you can put the actual 1-365 day of the year. You can use DAY_OF_YEAR(NOW()) to input this into MySQL. To pull it back out as a date you can use MAKEDATE(YEAR(NOW),repeat_doy). Instead of an asterisk to signify all, you can either use 0's or NULL.
With a cron like system you probably will not need to do that sort of calculation anyway.
Instead, it will probably be easier to just measure the day of year elsewhere (every computer and language can do this. In Unix it is just date "%j").
Solution
Split your one repeat_value into three separate values and turn them all into integers based on UNIX time values. Day is 1-7 (or 0-6 for Sunday to Saturday), Month is 1-12, and day of year is 1-365 (remember, we are not including 366 because we are basing our year on an arbitrary non-leap year).
If you want to pull information in your SELECT query in your original format, it is much easier to use concat to merge the three columns than it is to try to search and split on one column. You can also easily harness built in MySQL functions to quickly turn what you pull into real, current, days, without a bunch of effort on your part.
To implement it in your SQL database:
+----+----------+--------------+--------------+------------+
| id | event_id | repeat_day | repeat_month | repeat_doy |
+----+----------+--------------+--------------+------------+
| 1 | 11 | * | * | * |
| 2 | 12 | * | * | 2 |
| 3 | 13 | * | * | 4/2 |
| 4 | 14 | 23 | * | * |
| 5 | 15 | 30 | 5 | * |
+----+----------+--------------+--------------+------------+
Now you should be able to build one query to get all of this data together regardless of how complicated your query. By normalizing your table, you will be able to fully harness the power of relational databases, without the headaches and hacks.
Edit
Hugo Delsing made a great point in the comments below. In my initial example I provided a fix to leap years for day_of_year in which I chose to ignore Feb 29. A much better solution removes the need for a fix. Split day_of_year to month and day with a compound index. He also has a suggestion about weeks and number of weeks, but I will just recommend you read it for more details.
Try to write where condition using this:
substring_index(repeat_value,'_', 1)
instead of daily
substring_index(substring_index(repeat_value,'_', -2), '_', 1)
instead of monthly
and
substring_index(substring_index(repeat_value,'_', -1), '_', 1)
instead of dayOfWeek
I think you are overthinking the problem if you only want the events per month and not per day. Assuming that you always correctly fill the repeat_value, the query is very basic.
Basically all event occur every month where the repeat_value is either LIKE '%_*_%' or LIKE '%_{month}_%'.
Since you mentions PHP I'm assuming you are building the query in PHP and thus I used the same.
<?php
function buildQuery($searchDate) {
//you could/should do some more checking if the date is valid if the user provides the string
$searchDate = empty($searchDate) ? date("Y-m-d") : $searchDate;
$splitDate = explode('-', $searchDate);
$month = $splitDate[1];
//Select everything that started after the searchdate
//the \_ is because else the _ would match any char.
$query = 'SELECT *
FROM RepeatEvent
JOIN `Event`
ON `Event`.`id` = `RepeatEvent`.`event_id`
WHERE `Event`.`start_date_time` < \''.$searchDate.'\'
AND
(
`RepeatEvent`.`repeat_value` LIKE \'%\_'.$month.'\_%\'
OR `RepeatEvent`.`repeat_value` LIKE \'%\_*\_%\'
)
';
return $query;
}
//show querys for all months on current day/year
for ($month = 1; $month<=12; $month++) {
echo buildQuery(date('Y-'.$month.'-d')) . '<hr>';
}
?>
Now if the repeat_value could be wrong, you could add a simple regex check to make sure the value is always like *_*_* or *_*_*/*
You can use basic regular expressions in MySQL:
http://dev.mysql.com/doc/refman/5.0/en/pattern-matching.html
For a monthly event in May (first day) you can use a pattern like this (not tested):
[0-9\*]+\_[5\*]\_1
You can generate this pattern via PHP
I have a table 'mytable' like this
ID | dateTime | data |
------------------------------------------
1 | 2013-09-01 00:15:00 | some data |
2 | 2013-09-01 00:15:00 | some data |
4 | 2013-09-01 00:15:00 | some data |
5 | 2013-09-01 00:30:00 | some data |
6 | 2013-09-01 00:30:00 | some data |
7 | 2013-09-01 00:30:00 | some data |
8 | 2013-09-01 00:45:00 | some data |
9 | 2013-09-01 00:45:00 | some data |
10 | 2013-09-01 00:45:00 | some data |
I was fine before but I accidentally changed the dateTime to round to 15 minutes (I was supposed to round it for 5 minutes) please refere to this, No I want to round the time for 5 minutes.
I think the only way I can do this, is to get the dateTime of one record then check the record in the next row, if both are same then add 5 minutes into it.
How do I get the value of the next row and compare it with previous one?
Can anyone help me with this??
Thanks
This query will output the new datetime values, where I add 5 minutes every time the datetime is the same as the previous row, ordered by Id:
SELECT ID,
DATE_ADD(dateTime, INTERVAL 5 * (ID -
(SELECT MIN(ID) FROM MyTable T2 WHERE T2.dateTime = T1.dateTime)
) MINUTE) AS dateTime,
data
)
FROM MyTable T1
It works by adding 5 times the difference in ID values between the current row and the first row (minimum ID) of the same dateTime value.
While this will definitely do what you want, depending on how you rounded down to 15 minutes, the output will not necessarily be the same as if you had rounded down to 5 minutes from your original data. Your best option would be to restore from a backup.