how to calculate turned around datetime? [duplicate] - mysql

How do I extract the month and date from a mySQL date and compare it to another date?
I found this MONTH() but it only gets the month. I looking for month and year.


in Mysql Doku:
http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_extract
SELECT EXTRACT( YEAR_MONTH FROM `date` )
FROM `Table` WHERE Condition = 'Condition';


While it was discussed in the comments, there isn't an answer containing it yet, so it can be easy to miss.
DATE_FORMAT works really well and is flexible to handle many different patterns.
DATE_FORMAT(date,'%Y%m')
To put it in a query:
SELECT DATE_FORMAT(test_date,'%Y%m') AS date FROM test_table;


If you are comparing between dates, extract the full date for comparison. If you are comparing the years and months only, use
SELECT YEAR(date) AS 'year', MONTH(date) AS 'month'
FROM Table Where Condition = 'Condition';


SELECT * FROM Table_name Where Month(date)='10' && YEAR(date)='2016';


You may want to check out the mySQL docs in regard to the date functions. http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html
There is a YEAR() function just as there is a MONTH() function. If you're doing a comparison though is there a reason to chop up the date? Are you truly interested in ignoring day based differences and if so is this how you want to do it?


There should also be a YEAR().
As for comparing, you could compare dates that are the first days of those years and months, or you could convert the year/month pair into a number suitable for comparison (i.e. bigger = later). (Exercise left to the reader. For hints, read about the ISO date format.)
Or you could use multiple comparisons (i.e. years first, then months).

Related

Date and time conversion query in SQL

In my database table, there is a date column i.e. EXPECTED DATE which is in dd-mm-yyyy format, and the datatype of the column is text. Now, I want to convert the format to yyyy-mm-dd. But the date is not changing at all and also when I tried to get the timestamp for the expected date column . I am getting some errors. For date coming I have used this STR_TO_DATE. But the year is not coming like what I expect and the timestamp also.
For example:
select STR_TO_DATE ('30-11-2011', '%d,%m,%y') as date ;
returns a result as
2020-11-30
And for timestamp
select STR_TO_DATE ('2011,11,30 12,30,45', '%y,%m,%d, %H,%I,%S');
I am not getting errors.
Please help me get the correct answers for this problem.

For the first query you need to use the %Y. Remember that it is always better to use "Y" for the years when you are writing a query for year.
SELECT STR_TO_DATE("30,11,2011", "%d,%m,%Y");
For the second one also, you can use '%Y' in the place of '%y'. For minutes, use '%i' not '%I'. For hours and minutes, you can use whatever you like.
SELECT STR_TO_DATE("2011,11,30 12,30,45", "%Y,%m,%d %h,%i,%s");
Refer to the below documentation for more clarification on SQL commands.

You need %Y (capital Y) for the 4 digit year, when using MySQL's STR_TO_DATE. Also, minutes is represented by %i, not %I, the latter which is hours on a 0 to 12 scale. So use:
SELECT STR_TO_DATE('30-11-2011', '%d-%m-%Y');
SELECT STR_TO_DATE('2011,11,30 12,30,45', '%Y,%m,%d %H,%i,%S');

For the first query you need to use the %Y'.
SELECT STR_TO_DATE("30,11,2011", "%d,%m,%Y");
For minutes, use this one only '%i'.
SELECT STR_TO_DATE("2011,11,30 12,30,45", "%Y,%m,%d %h,%i,%s");

Compare dates using dayofyear() function

I want to compare two dates trans-date and proc-date using dayofyear function. The function doesn’t work if the two dates are in separate years. Can anyone help me with that?
Example:
trans-date = 2019-01-12”
Proc-date= “2020-01-01”
Dayofyear(trans-date)=12
Dayofyear (proc-date) = 1
Logically, proc-date is greater than trans-date but dayofyear doesn’t work that way. So, how can I calculate the dates where I can get trans-date < proc-date?
Thank you.

Perhaps you want to compare the month/date without the year. If so, you date use date_format():
where date_format(trans_date, '%Y-%m') < date_format(proc_date, '%Y-%m')

I want to find the previous month's date for specific date in SQL

I want to get the previous month date for specific dates in SQL. For example: 6.21.19 has a previous month date of 5.21.19.
I am just trying to get comps from this.
MONTH( curdate() ) -1
I need to return the previous month date.

Welcome to the board Arie. Judging from your question and responses, you need a range of dates and their prior month relations. The easiest way would be for all of the dates you need to look up to be in a table, then the answers provided so far would work. Since that doesn't appear to be the case, I'm guessing you are creating date ranges on the fly.
So lets assume you need exactly the data shown in your example, there are two parts to this, first you need to get a list of days that you want to look up, then you need to get the day in the prior month. There are lots of ways to get a sequence of days, but for simplicity I'll use a recursive CTE. Once I have the date range, I'll just select the dates and their prior month date as well.
with Date_CTE as (select cast('6/1/2019' as datetime) as repDate
union all
select dateadd(day, 1, repdate) as repDate
from Date_CTE
where repDate < '06/07/2019')
select repDate, dateadd(month, -1, repDate) as PriorDate
from Date_CTE
CTEs are helpful functions and you can get more details on them here, but it's worth noting there are many ways to do this. Hope this gets you pointed in the right direction.

SELECT yourDateColumn, yourDateColumn-interval 1 month as prevMonthDate

PURE SQL get days beteen given date and current date, without functions

I need to get number of days between 2 dates, a given one and current date.
But in pure SQL, I mean without usign functions, it is possible?
For exaple
SELECT days (t.givenDate) - days (current date) FROM table t
Have you any idea?
Thaks a lot.

The built-in function is datediff(). The equivalent for the above is:
SELECT datediff(t.givenDate, curdate()) FROM table t;
Normally, givenDate would be in the past and you would want the arguments in the other order.

MySQL Query Group By Date

I have tried various recommendations based off of other posts with no avail.
I have a database scheme of records with a Created_Date Key, and Value would be 01/01/2017
I am trying to query the database records to give a returned count of How many records per month and which month those fall in line with.
With the following
SELECT SQL_NO_CACHE MONTH(`Created_Date`), COUNT(*)
FROM `CRM_Leads`
GROUP BY MONTH(`Created_Date`)
I return
MONTH(`Created_Date`) COUNT(*)
NULL 872
I have also tried almost all the variations on the following post
Count records for every month in a year
Any help would be appreciated.

assuming your created_date is a string of format ('dd-mm-yyyy') the you should convert as date with str_to_date
SELECT SQL_NO_CACHE MONTH(str_to_date(`Created_Date`, '%d/%m/%Y')), COUNT(*)
FROM `CRM_Leads`
GROUP BY MONTH(str_to_date(`Created_Date`, '%d/%m/%Y'))

For as long as you store date/time information as strings, you will have great difficulty using any date/time specific functions and features. If you are getting NULL from MONTH(str_to_date(Created_Date, '%d/%m/%Y')) then the str_to_date isn't converting the strings to dates and the most likely reason for this is the d m y "pattern" is not corrrect.
All you have old us about your "strings that might be dates" is that one of them looks like this: 01/01/2017. Now that could be DD/MM/YYYY or MM/DD/YYYY and we simply cannot tell which one is correct from the single value you have chosen to share with us. Look for any day value greater then 12 in your data e.g. 17/01/2017 ==> DD/MM/YYYY or 01/17/2017 ==> MM/DD/YYYY
Once you have made the choice of which pattern your "strings that might be dates" follow; apply that pattern in the str_to_date() function. You migh want to try a few different patterns to get the best one (and these are just 3 of many you could try):
# which pattern is best for you?
SELECT Created_Date
, str_to_date(`Created_Date`, '%d/%m/%Y') "d/m/y"
, str_to_date(`Created_Date`, '%m/%d/%Y') "m/d/y"
, str_to_date(`Created_Date`, '%Y-%m-%d') "y-m-d"
FROM `CRM_Leads`
You will not have success with your group by query until you choose the most appropriate d m y pattern to apply in teh str_to_date function. Note here that you might also have a variety of patterns in your data, in which case you have an even bigger problem to solve.
Once you have made the choice of which pattern your "strings that might be dates" follow; apply that pattern in the str_to_date() function and ONLY THEN your group by query will work.