phpmyadmin: database events - mysql

I'm trying to move records from one table (upcoming) to another table (today) when the date of the record (from upcoming) equals today's date. How would I go about doing so using recurring events in phpmyadmin?

You certainly can use a MySQL event that runs at (actually shortly after) midnight each day. You can do whatever you want in that event. Here's an example.
CREATE EVENT `midnight_event`
ON SCHEDULE
EVERY 1 DAY STARTS '2015-10-10 00:00:00'
ON COMPLETION PRESERVE
DISABLE ON SLAVE
DO BEGIN
START TRANSACTION;
INSERT
INTO todays_table
VALUES (col, col, col, col)
SELECT col, col, col
FROM pending_table
WHERE time_stamp >= CURDATE()
AND time_stamp < CURDATE() + INTERVAL 1 DAY;
DELETE
FROM pending_table
WHERE time_stamp >= CURDATE()
AND time_stamp < CURDATE() + INTERVAL 1 DAY;
COMMIT;
END
Others have commented about the wisdom of this sort of data design, with rows moving from table to table. There's considerable merit in their comments. If you want a "table" with today's events in it, consider a view. This one will look just like the table you maintain with the event I mentioned.
CREATE OR REPLACE VIEW todays_table AS
SELECT *
FROM pending_table
WHERE time_stamp >= CURDATE()
AND time_stamp < CURDATE() + INTERVAL 1 DAY

Related

Create Trigger to delete rows that are >90 days old

Trying to create a trigger that will delete any record that is 90 days old. I used a trigger statement from stackoverflow that I have found and changed the statement a bit, but in my MySQL Workbench, I am getting a syntax error. I cannot seem to figure what is wrong.
Below is my query:
create trigger user_connections_dump after insert on user_connections
for each row
begin
delete from connection_time where Date('2014-06-09') > Date('now','-90 days')
end;
Your need looks more like an Event than a Trigger.
CREATE EVENT IF NOT EXISTS `Clean_Older_Than_90_days_logs`
ON SCHEDULE
EVERY 1 DAY_HOUR
COMMENT 'Clean up log connections at 1 AM.'
DO
DELETE FROM log
WHERE log_date < DATE_SUB(NOW(), INTERVAL 90 DAY)
References:
MySQL Event Scheduler on a specific time everyday
CREATE TRIGGER user_connections_dump
AFTER INSERT ON user_connections
FOR EACH ROW
DELETE FROM log
WHERE log_date < DATE_SUB(NOW(), INTERVAL 90 DAY)
You should be comparing the date column in the log table, not a literal date. Then you use DATE_SUB to subtract dates, not the Date function.
CREATE EVENT IF NOT EXISTS `Delete_Older_Than_90_Days`
ON SCHEDULE EVERY 1 DAY
STARTS STR_TO_DATE(DATE_FORMAT(NOW(),'%Y%m%d 0100'),'%Y%m%d %H%i') + INTERVAL 1 DAY
DO
DELETE LOW_PRIORITY FROM log WHERE log_date < DATE_SUB(NOW(),INTERVAL 90 DAY)

MySQL CurDate() format to use MySQL EVENT for deleting (cleaning table) data after a day?

I have a MySQL table named registered where one of my rows named time is of type timestamp and I wanted to add an EVENT where all the entries in this table are deleted if they are older than one day. I have this so far...
CREATE EVENT delete_registration_data
ON SCHEDULE EVERY 1 DAY
DO
DELETE FROM `registered` where time < DATE_SUB(CurDate(), INTERVAL 1 DAY);
What I noticed however is that the timestamp datatype is made up of the CURDATE() and CURTIME() e.g. 2008-11-11 12:45:34. Would this cause a problem for the EVENT handler to delete from the table?
CREATE EVENT delete_registration_data
ON SCHEDULE EVERY 1 DAY
DO
DELETE FROM `registered` where date(time) < DATE_SUB(CurDate(), INTERVAL 1 DAY);

SQL Query for reservation dates that break a month end?

I'm using a custom PHP function to produce a visual calendar for a single month that blocks out dates based on a table that contains an start date, and an duration - For example:
...This is produced by data saying that the table should be blocked out for 4 days from the 14th, and 7 days from the 27th.
The query looks something like this:
SELECT GROUP_CONCAT(DATE_FORMAT(start_date,'%d'),':', event_duration) AS info
FROM events
WHERE YEAR(start_date = '2012'
AND MONTH(start_date) = '07'
ORDER BY start_date
(You could safely ignore the group concat and return the data as individual rows, that doesn't really matter).
I'm looking for a modification to the query that would block out dates at the start of the month IF an event starts in the previous month, but its length takes it into the following.
For instance - in the above example, the event on the 27th is actually scheduled to last 7 days in the database, so if I ran the query for MONTH(start_date) = '08' I'd like to say the first two dates blocked out, which they wouldn't currently be, because the start date that would block it out is not in the month being selected.
I'm fairly sure there's a subquery or something in there to grab the rows, but I just can't think of it. Any takers?
EDIT
The answer from Salman below pointed me in the directon I wanted to go, and I came up with this as a way of getting carryovers from the previous month to show as '1st' of the month with the number of remaining days:
SELECT IF(MONTH(start_date) < '08', '2012-08-01', start_date) AS starter,
IF(MONTH(start_date) < '08', duration - DATEDIFF('2012-08-01',start_date), duration) AS duration
FROM EVENTS
WHERE YEAR(start_date) = '2012'
AND (MONTH(start_date) = '08' OR MONTH(start_date + INTERVAL duration DAY) = '08')
Obviously a lot of variables there to replace in PHP, so maybe there's an even better way?
Original Answer:
Assuming that the month in question is 2012-07, you need this query:
SELECT column1, column2, columnN
FROM `events`
WHERE `start_date` <= '2012-07-01'
AND `start_date` + INTERVAL `duration` DAY > '2012-07-01'
ORDER BY start_date
Revised Answer:
Apparently you need a query that checks for overlapping (or conflicting) dates. The example dates are 2012-07-01 through 2012-08-01 and the query is:
SELECT *
FROM events
WHERE '2012-08-01' > start_date
AND start_date + INTERVAL duration DAY > '2012-07-01'
ORDER BY start_date
To constrain the start date and interval, you can use SELECT ... CASE statement:
SELECT
CASE
WHEN start_date < '2012-07-01' THEN '2012-07-01'
ELSE start_date
END AS start_date_copy,
CASE
WHEN start_date < '2012-07-01' THEN duration - DATEDIFF('2012-07-01', start_date)
ELSE duration
END AS duration_copy,
FROM ...
The answer I was looking for, thanks to the other contributor for pointing me in the right direction and enabling me to solve it!
This is based on $yyyy and $mm coming from PHP (in my case, into a function call), and selecting individual rows rather than grouping:
SELECT start_date, duration
FROM reservations
WHERE YEAR(start_date) = '".$yyyy."'
AND MONTH(start_date) = '".$mm."'
UNION
SELECT '".$yyyy."-".$mm."-01',
duration - DATEDIFF('".$yyyy."-".$mm."-01',start_date)
FROM reservations
WHERE YEAR(start_date) = '".$yyyy."'
AND MONTH(start_date) < '".$mm."'
AND MONTH(start_date + INTERVAL duration DAY) = '".$mm."'
ORDER BY start_date

mysql date_sub using a field as interval

I need help with mysql and date_sub(). I have a table call Activity
Activity(id,deadline,alert)
Activity(1,'2011-04-18','1 DAY');
Activity(2,'2011-04-13','1 MONTH');
Every row in A have an 'alert', this field indicate how time before the deadline an activity have to reported.
For example
On 2011-04-17 I have to report the activity with 'id' 1
On 2011-03-14 I have to report the activity with 'id' 2
I trying to use date_sub() functions, but I can't use a field as params of this function. Any idea how to fix this?
SELECT *
FROM `activities`
WHERE date_sub(`deadline`, INTERVAL alert) >= CURDATE();
Split the alert into 2 fields
Alert_count: integer
Alert_period: enum('hour','day','month','week')
And change the query like so:
SELECT *
FROM `activities`
WHERE CASE alert_period
WHEN 'hour' THEN date_sub(`deadline`, INTERVAL alert_count HOUR) >= CURDATE();
WHEN 'day' THEN date_sub(`deadline`, INTERVAL alert_count DAY) >= CURDATE();
...
END CASE
If the number of alerts is small, you could write out a case:
WHERE case
when alert = '1 DAY' then date_sub(`deadline`, INTERVAL 1 DAY)
when alert = '1 MONTH' then date_sub(`deadline`, INTERVAL 1 MONTH)
... etc ...
end >= CURDATE();
Although this solution will work it's not the most efficient way of storing this data because each time you query for this data MySQL must look at the interval value in every row, compute it against deadline date and then return you the answer.
If you were to compute this information just before you insert the data and store alert_date as a DATE column then (assuming you index it too) it'd be very fast for MySQL to find the rows with a query like:
SELECT id FROM activity WHERE alert=CURRENT_DATE();
even more efficient (it'd allow it to be query cached):
SELECT id FROM activity WHERE alert="2011-04-23";
Strings are not allowed after INTERVAL, you can convert your all alert limit to day on one column.
Activity(id,deadline,alert)
Activity(1,'2011-04-18','1');
Activity(2,'2011-04-13','30');
and use as:
SELECT *
FROM `activities`
WHERE date_sub(`deadline`, INTERVAL alert DAY) >= CURDATE();

How to get first day of every corresponding month in mysql?

I want to get first day of every corresponding month of current year. For example, if user selects '2010-06-15', query demands to run from '2010-06-01' instead of '2010-06-15'.
Please help me how to calculate first day from selected date. Currently, I am trying to get desirable using following mysql select query:
Select
DAYOFMONTH(hrm_attendanceregister.Date) >=
DAYOFMONTH(
DATE_SUB('2010-07-17', INTERVAL - DAYOFMONTH('2010-07-17') + 1 DAY
)
FROM
hrm_attendanceregister;
Thanks
Is this what you are looking for:
select CAST(DATE_FORMAT(NOW() ,'%Y-%m-01') as DATE);
You can use the LAST_DAY function provided by MySQL to retrieve the last day of any month, that's easy:
SELECT LAST_DAY('2010-06-15');
Will return:
2010-06-30
Unfortunately, MySQL does not provide any FIRST_DAY function to retrieve the first day of a month (not sure why). But given the last day, you can add a day and subtract a month to get the first day. Thus you can define a custom function:
DELIMITER ;;
CREATE FUNCTION FIRST_DAY(day DATE)
RETURNS DATE DETERMINISTIC
BEGIN
RETURN ADDDATE(LAST_DAY(SUBDATE(day, INTERVAL 1 MONTH)), 1);
END;;
DELIMITER ;
That way:
SELECT FIRST_DAY('2010-06-15');
Will return:
2010-06-01
There is actually a straightforward solution since the first day of the month is simply today - (day_of_month_in_today - 1):
select now() - interval (day(now())-1) day
Contrast that with the other methods which are extremely roundabout and indirect.
Also, since we are not interested in the time component, curdate() is a better (and faster) function than now(). We can also take advantage of subdate()'s 2-arity overload since that is more performant than using interval. So a better solution is:
select subdate(curdate(), (day(curdate())-1))
This is old but this might be helpful for new human web crawlers XD
For the first day of the current month you can use:
SELECT LAST_DAY(NOW() - INTERVAL 1 MONTH) + INTERVAL 1 DAY;
You can use EXTRACT to get the date parts you want:
EXTRACT( YEAR_MONTH FROM DATE('2011-09-28') )
-- 201109
This works well for grouping.
You can use DATE_FORMAT() function in order to get the first day of any date field.
SELECT DATE_FORMAT(CURDATE(),'%Y-%m-01') as FIRST_DAY_CURRENT_MONTH
FROM dual;
Change Curdate() with any other Date field like:
SELECT DATE_FORMAT(purchase_date,'%Y-%m-01') AS FIRST_DAY_SALES_MONTH
FROM Company.Sales;
Then, using your own question:
SELECT *
FROM
hrm_attendanceregister
WHERE
hrm_attendanceregister.Date) >=
DATE_FORMAT(CURDATE(),'%Y-%m-01')
You can change CURDATE() with any other given date.
There are many ways to calculate the first day of a month, and the following are the performance in my computer (you may try this on your own computer)
And the winner is LAST_DAY(#D - interval 1 month) + interval 1 day
set #D=curdate();
select BENCHMARK(100000000, subdate(#D, (day(#D)-1))); -- 33 seconds
SELECT BENCHMARK(100000000, #D - INTERVAL (day(#D) - 1) DAY); -- 33 seconds
SELECT BENCHMARK(100000000, cast(DATE_FORMAT(#D, '%Y-%m-01') as date)); -- 29 seconds
SELECT BENCHMARK(100000000, LAST_DAY(#D - interval 1 month) + interval 1 day); -- 26 seconds
I'm surprised no one has proposed something akin to this (I do not know how performant it is):
CONCAT_WS('-', YEAR(CURDATE()), MONTH(CURDATE()), '1')
Additional date operations could be performed to remove formatting, if necessary
use date_format method and check just month & year
select * from table_name where date_format(date_column, "%Y-%m")="2010-06"
SELECT LAST_DAY(date) as last_date, DATE_FORMAT(date,'%Y-%m-01') AS fisrt_date FROM table_name
date=your column name
The solutions that use last_day() and then add/subtract a month and a day are not interchangeable.
Example:
date_sub(date_add(last_day(curdate()), interval 1 day), interval 3 month)
always works for any supplied number of months you want to go back
date_add(date_sub(last_day(now()), interval 3 month), interval 1 day)
will fail in some cases, for instance if your current month has 30 days and the month you're subtracting back to (and then adding a day) has 31.
date_add(subdate(curdate(), interval day(?) day), interval 1 day)
change the ? for the corresponding date
This works fine for me.
date(SUBDATE("Added Time", INTERVAL (day("Added Time") -1) day))
** replace "Added Time" with column name
Use Cases:
If you want to reset all date fields except Month and Year.
If you want to retain the column format as "date". (not as "text" or "number")
Slow (17s):
SELECT BENCHMARK(100000000, current_date - INTERVAL (day(current_date) - 1) DAY);
SELECT BENCHMARK(100000000, cast(DATE_FORMAT(current_date, '%Y-%m-01') as date));
If you don't need a date type this is faster:
Fast (6s):
SELECT BENCHMARK(100000000, DATE_FORMAT(CURDATE(), '%Y-%m-01'));
SELECT BENCHMARK(100000000, DATE_FORMAT(current_date, '%Y-%m-01'));
select big.* from
(select #date := '2010-06-15')var
straight_join
(select * from your_table where date_column >= concat(year(#date),'-',month(#date),'-01'))big;
This will not create a full table scan.