MySQL unix_timestamp calculation - mysql

I have an employees table with a field called start which is a unix_timestamp of the date the employee started. I'm calculating their most recent anniversary using a loop in PHP
$year_start = $employee['start'];
while(strtotime('+1 year', $year_start) <= time()){
$year_start = strtotime('+1 year', $year_start);
}
That works fine, but I'd like to do it as a "virtual field" in the SQL query. Anyone got a clever MySQL query that'll get the most recent anniversary in unix_timestamp?

Thanks to Barranka alerting me to the existence of date_add I think I've got a solution.
UNIX_TIMESTAMP( DATE_ADD ( FROM_UNIXTIME(start), interval +FLOOR( DATEDIFF(NOW(), FROM_UNIXTIME(start) )/365 ) year))

Related

How to compare a date when the date is stored as a varchar

The dates in my database are stored as varchars instead of date formats due to the way it was first built.
The dates look like this:
e.g. 1/3/2015 and
10/3/2015
I'm trying:
"SELECT COUNT(*) n FROM tracker WHERE TIMESTAMP(STR_TO_DATE(date, '%d/%m/%Y'))<=NOW()"
However, that's not working. It is returning the count of all records, regardless of the date.
How can I count only the records where the date is today or in the past?
You do not need TIMESTAMP():
SELECT COUNT(*) as n
FROM tracker
WHERE STR_TO_DATE(date, '%d/%m/%Y') <= NOW()
You should pay attention to the functions STR_TO_DATE and NOW(), the first return a date, the second is a timestamp.
When you convert STR_TO_DATE(date, '%d/%m/%Y') you will get a date with hours, minutes and seconds as 00:00:00
Using CURRENT_DATE perhaps will match more closely the original requirements
SELECT COUNT(*) as n
FROM tracker
WHERE STR_TO_DATE(date, '%d/%m/%Y') <= CURRENT_DATE
Also I suggest you to rename the column 'date'

Find data of a whole month in sql

I have this query where I provide to-date & from date.
SELECT *
FROM sales
WHERE date between to-date AND from-date;
Now I want to execute this query with following parameters
to-date = Oct-2015
some-other-date = Oct-2015
That is I want records of the whole month.
How would I do that in a query where I have to and from dates provided it will work for both scenarios where months can be same and different as well.
Update:
dataType for column date is date
You can find the first day of the month containing any given timestamp with an expression like this. For example by using the timestamp NOW(), this finds the first day of the present month.
(DATE(NOW() - INTERVAL DAYOFMONTH(DATE(NOW()))
That's handy, because then you can use an expression like
(DATE(NOW() - INTERVAL DAYOFMONTH(DATE(NOW())) - INTERVAL 1 MONTH
to find the beginning of the previous month if you like. All sorts of date arithmetic become available.
Therefore, you can use an expression like the following to find all records with item_date in the month before the present month.
WHERE item_date>=(DATE(NOW()-INTERVAL DAYOFMONTH(DATE(NOW()))- INTERVAL 1 MONTH
AND item_date < (DATE(NOW()-INTERVAL DAYOFMONTH(DATE(NOW()))
Notice that we cast the end of a range of time as an inequality (<) to the moment just after then end of the range of time.
You may find this writeup useful. http://www.plumislandmedia.net/mysql/sql-reporting-time-intervals/
It's often useful to create a stored function called TRUNC_MONTH() to perform the conversion of the arbitrary timestamp to the first day of the month. It makes your SQL statements easier to read.
select * from sales
where from-date >= 1-Oct-2015
and to-date <= 1-Nov-2015
Update
select * from sales
where date >= from-date
and date <= to-date
Here is SQLFIDDLE
You Can get month from your both to and from dates and find records of that month
SELECT * FROM sales
WHERE MONTH('2002-01-03') AND MONTH('2002-01-3')
SqlFiddle of Using Month Function

curdate() till rest of the month mysql

I'm trying to retrieve data between today and the rest of this month.
select * from table where date between curdate() and endmonth();
My experience with mysql dates/times is pretty bad.
MySQL has a LAST_DAY function that returns the last day of the passed month. I'd use that:
SELECT * FROM table WHERE date BETWEEN CURDATE() AND LAST_DAY(CURDATE());
I'd go with a little trick with DATE_FORMAT()
select * from table where date between curdate() and DATE_FORMAT(CURDATE(), '%Y-%m-31');
This way you don't have to deal with complicated and year(...) = ... and month(... . It's just nice and easy to write.
Read more about it here.
SELECT * FROM table WHERE date BETWEEN CURDATE() AND LAST_DAY(CURDATE());

Calculate difference between dates

The title might be a bit misleading, but what I want is:
SELECT * FROM table ORDER BY pid ASC
And in one of the columns I have a DATE(). I want to compare the current date (not time) and return how many days are left till that date. Let's say the date is 2013-04-20 and today's date is 2013-04-16 I don't want to get any data if it's < current date. If it is I want it returned in days.
I've been looking around here and I've found no way to do it, and I can't for the love of me figure it out.
If you're looking for the difference between two date you can use the GETDATE function in MS SQL
SELECT DATEDIFF(DD, DateOne, DateTwo) FROM TABLE
This will return the difference in number of days between the two dates.
If you only want rows where the date field is less than or equal to today's date you can use:
SELECT DATEDIFF(DD, DateField, GETDATE())
FROM TableName
WHERE DateField <= GETDATE()
If you're using MySQL you can use DATEDIFF()
SELECT
DATEDIFF(NOW(), date_column) AS days_diff
FROM
tablename
Get the difference between two dates (ANSI SQL)
select the_date_column - current_date as days_left
from the_table
where the_date_column - current_date <= 4;
SQLFiddle: http://sqlfiddle.com/#!12/3148d/1

MySQL: Curdate() vs Now()

What is difference between MySQL Curdate() and Now()?
For questions like this, it is always worth taking a look in the manual first. Date and time functions in the mySQL manual
CURDATE() returns the DATE part of the current time. Manual on CURDATE()
NOW() returns the date and time portions as a timestamp in various formats, depending on how it was requested. Manual on NOW().
Just for the fun of it:
CURDATE() = DATE(NOW())
Or
NOW() = CONCAT(CURDATE(), ' ', CURTIME())
CURDATE() will give current date while NOW() will give full date time.
Run the queries, and you will find out whats the difference between them.
SELECT NOW(); -- You will get 2010-12-09 17:10:18
SELECT CURDATE(); -- You will get 2010-12-09
Actually MySQL provide a lot of easy to use function in daily life without more effort from user side-
NOW() it produce date and time both in current scenario whereas
CURDATE() produce date only, CURTIME() display time only, we can use one of them according to our need with CAST or merge other calculation it, MySQL rich in these type of function.
NOTE:- You can see the difference using query select NOW() as NOWDATETIME, CURDATE() as NOWDATE, CURTIME() as NOWTIME ;