Add one date to date in MySql - mysql

I am setting up a MySQL (Maria) where I am going to upload demo data for an application. In the demo date there will be many different dates from the last 6 months.
What I need to do is to keep all dates the same number of days from today all the time. So a date that is x number of days earlier or later than today keep that interval constant.
The demo data will be used in a PHP application so it is maybe an option to run PHP code to change the dates every day, or is it best done any other way?
I have been trying to just add +1, but it does not work on dates.

Related

Using MySQL to return row between to strings with date, but without year

I am currently working on a project in which I want to store commemorative days (like January 8th's World Leprosy Day) in a database. At this moment they're stored in a table which contains:
- an ID
- the date as varchar (stored European style, e.d. "8-01" for January 8th)
- length of the commemorative day (as some span multiple days)
- and the name
The reason I am storing the date as varchar is because the year is irrelevant, and I'm a bit reluctant to just store a year (e.g. 2013) in the database and truncate it.
But here's the problem: I can't seem to find a way to construct a query that will get the rows between dates. I think it's because the way the dates are stored in the database.
I already tried (given day = "8-01")
SELECT * FROM comdays WHERE date(day) BETWEEN date("1-01") AND date("20-01")
But to no avail.
Is there a way to get this thing going with strings? Or do I have to change the date column into a MySQL DATE format?
Thanks in advance!
If you really want to keep non standard date field in MYSQL you will need to use the following format 0108-> mmdd this format allows calculations.
It might also be worth reading the following answers to similar question Save day and month in database

Microsoft Access Date Function

I am trying to create a query on a table that filters out dates. I need to display all records previous to a specific date, but need this to be dynamically updated annually.
Specifically, I need to find dates prior to October 1 of the previous year. (i.e. anything prior to Oct 1, 2012.)
I know I can use '<#10/1/2012#' but would like to make this dynamic to update every year, as this same function will be utilized for multiple queries.
I have tried several iterations of the Date() function to get this to work, to no avail.
Things that don't work are...
Year([TrainingDate])
[TrainingDate] < DateSerial(Year(Date())-1,10,1)
Date() is the current date, so Year(Date()) is the current year.

php mysql storing just hours minutes seconds

I know a typical timestamp in any format readable or otherwise is always equivalent to a date time second day month year etc. However I want to be able to search by hours minutes seconds where the day month year are irrelevant. So I am trying to wrap my head around that ability and what would be the best method of storing time so I can create searches around that alone without m-d-y getting in my way.
Try using the TIME field type. The TIMESTAMP field type should only be used anyway when you want MySQL to update the field when updating the row.
$hour = date("H",$date); $minute = date("i",$date); $second = date("s",$date);
and save them on your table as hour,minute and second

Checking if the UNIX timestamp stored in MySQL DB is this weeks or this months?

I have a MySQL DB, and in one of the tables I have stored the time in which the content was submitted its in the form of a UNIX timestamp, the column is called content_time. Below are two pseudo examples of queries to demonstrate what I'm trying to accomplish, just not sure how to go by doing this (although I understand I will need do some some comparisons between the current and stored timestamps within the WHERE clause):
SELECT * FROM content
WHERE content_time = THIS WEEKS
(the content was posted at any time/day within the current week)
SELECT * FROM content
WHERE content_time = THIS MONTHS
(the month and year from content_time match with the current)
Appreciate all help.
See MySQL's Date and Time Functions, specifically FROM_UNIXTIME(), WEEK() and MONTH(). Keep in mind that when checking is it the same week or month you probably also want to check is it the same year.
Another option is to generate start and end timestamps for the time range youre intrested in (ie timestamp for the beginning of the week and for the end of the week) and then use WHERE(content_time BETWEEN start AND end)

MySql timestamp timezone weirdness

I want to grab records from a table based on the day of the month the record was created.
This information is stored in a Unix timestamp. During testing I created new test records and threw in some timestamps for specific times that I had converted to timestamps using an online converter. I used...
01/29/2010-02:00:00
Right now I'm using...
FROM_UNIXTIME(timestamp, '%d') == 29
This should work for all times on the 29th day of every month. But it is calculating the timestamp to be 5 hours behind the actual value of the timestamp. When I just run a FROM_UNIXTIME on the timestamp it returns 01/28/2010-21:00:00. I was hoping someone could give an explanation for this, if there is an easy fix or should I just code the program to expect the timezone to be a factor.
The FROM_UNIXTIME function automatically converts the datetime to the current timezone.