I am merging 2 huge tables in Snowflake and I have 2 columns (one on each table):
"Year_birth" and "Exam_date" and the info inside looks like this respectively:
"1918" and "2007-03-13" (NUMBER(38,0) and VARCHAR(256))
I only want to merge the rows where the difference (i.e., age when the exam was made) is ">18" and "<60"
I was playing around with SELECT DATEDIFF(year,Exam_date, Year_birth) with no success.
Any ideas on how would I do it in Snowflake?
Cheers!
You only have a year, so there is not much you can do about the specific day of the year -- you need to deal with approximations.
So, extract the year from the date string (arggh! it should really be a date) and just compare them:
where (left(datestr, 4)::int - yearnum) not between 18 and 60
I would strongly advise you to fix the database and store these values using a proper date datatype.
You will need to convert the integer year into a date before doing a datediff
example:
set YearOfBirth = 1918;
set ExamDate = '2007-03-03'::DATE;
-- select $YearofBirth as YearofBirth, $ExamDate as ExamDate;
select $YearofBirth as YearofBirth,($YearofBirth::TEXT||'-01-01')::DATE as YearofBirthDate, $ExamDate as ExamDate, datediff(year,($YearofBirth::TEXT||'-01-01')::DATE,$ExamDate) as YearsSinceExam;
USE YEARS_DIFF IN WHERE CLAUSE TO FILTER DIFFERENCE BETWEEN 18 & 60
SELECT DATEDIFF( YEAR,'2007-03-03',TO_DATE(2018::CHAR(4),'YYYY')) YEARS_DIFF;
Related
I have a column due date in the format 20210701 (YYYYMMDD), using SQL I want to extract all the dates apart from 5th of particular month ( As highlighted in the pic below )
I used the below code:
SELECT Due_Date_Key
FROM Table
WHERE Due_Date_Key <>20210705
However the error in the above code is it will exclude only the month of jul but not for other months.
How can extract the dates apart from 5th from the entire column.
Help would be much appreciated.
Note that column DUE_DATE_KEY is numeric.
A more SQLish way would be to convert string to date and then check if day is not 5
SELECT * FROM Table
WHERE DATE_PART('day', to_date(cast(DUE_DATE_KEY as varchar), 'YYYYMMDD')) != 5
Using modulo operator to determine whether the last two digits of DUE_DATE_KEY are 05.
select * from T where DUE_DATE_KEY % 100 <> 5
Using your sample data, the above query returns the following:
due_date_key
20210701
20210708
20210903
Refer to this db fiddle
I have a table with a date column where date is stored in this format:
2012-08-01 16:39:17.601455+0530
How do I group or group_and_count on this column by month?
Your biggest problem is that SQLite won't directly recognize your dates as dates.
CREATE TABLE YOURTABLE (DateColumn date);
INSERT INTO "YOURTABLE" VALUES('2012-01-01');
INSERT INTO "YOURTABLE" VALUES('2012-08-01 16:39:17.601455+0530');
If you try to use strftime() to get the month . . .
sqlite> select strftime('%m', DateColumn) from yourtable;
01
. . . it picks up the month from the first row, but not from the second.
If you can reformat your existing data as valid timestamps (as far a SQLite is concerned), you can use this relatively simple query to group by year and month. (You almost certainly don't want to group by month alone.)
select strftime('%Y-%m', DateColumn) yr_mon, count(*) num_dates
from yourtable
group by yr_mon;
If you can't do that, you'll need to do some string parsing. Here's the simplest expression of this idea.
select substr(DateColumn, 1, 7) yr_mon, count(*) num_dates
from yourtable
group by yr_mon;
But that might not quite work for you. Since you have timezone information, it's sure to change the month for some values. To get a fully general solution, I think you'll need to correct for timezone, extract the year and month, and so on. The simpler approach would be to look hard at this data, declare "I'm not interested in accounting for those edge cases", and use the simpler query immediately above.
It took me a while to find the correct expression using Sequel. What I did was this:
Assuming a table like:
CREATE TABLE acct (date_time datetime, reward integer)
Then you can access the aggregated data as follows:
ds = DS[:acct]
ds.select_group(Sequel.function(:strftime, '%Y-%m', :date_time))
.select_append{sum(:reward)}.each do |row|
p row
end
HI all,
i have one sql table and field for that table is
id
name
expireydate
Now i want only those record which one is expired within 45 days or 30 days.
how can i do with sql query .?
I have not much more exp with sql .
Thanks in advance,
If you are using mysql then try DATEDIFF.
for 45 days
select * from `table` where DATEDIFF(now(),expireydate)<=45;
for 30 days
select * from `table` where DATEDIFF(now(),expireydate)<=30;
In oracle - will do the trick instead of datediff and SYSDATE instead of now().[not sure]
In sql server DateDiff is quite different you have to provide unit in which difference to be taken out from 2 dates.
DATEDIFF(datepart,startdate,enddate)
to get current date try one of this: CURRENT_TIMESTAMP or GETDATE() or {fn NOW()}
You can use a simple SELECT * FROM yourtable WHERE expireydate < "some formula calculating today+30 or 45 days".
Simple comparison will work there, the tricky part is to write this last bit concerning the date you want to compare to. It'll depend of your environment and how you stored the "expireydate" in the database.
Try Below:-
SELECT * FROM MYTABLE WHERE (expireydate in days) < ((CURRENTDATE in days)+ 45)
Do not execute directly! Depending of your database, way of obtaining a date in days will be different. Go look at your database manual or please precise what is your database.
How best store year, month, and day in a MySQL database so that it would be easily retrieved by year, by year-month, by year-month-day combinations?
Let's say you have a table tbl with a column d of type DATE.
All records in 1997:
SELECT * FROM tbl WHERE YEAR(d) = 1997
SELECT * FROM tbl WHERE d BETWEEN '1997-01-01' AND '1997-12-31'
All records in March of 1997:
SELECT * FROM tbl WHERE YEAR(d) = 1997 AND MONTH(d) = 3
SELECT * FROM tbl WHERE d BETWEEN '1997-03-01' AND '1997-03-31'
All records on March 10, 1997:
SELECT * FROM tbl WHERE d = '1997-03-10'
Unless a time will ever be involved, use the DATE data type. You can use functions from there to select portions of the date.
I'd recommend the obvious: use a DATE.
It stores year-month-day with no time (hour-minutes-seconds-etc) component.
Store as date and use built in functions:day(), month() or year() to return the combination you wish.
What's wrong with DATE? As long as you need Y, Y-M, or Y-M-D searches, they should be indexable. The problem with DATE would be if you want all December records across several years, for instance.
This may be related to the problem that archivists have with common date datatypes. Often, you want to be able to encode just the year, or just the year and the month, depending on what information is available, but you want to be able to encode this information in just one datatype. This is a problem which doesn't apply in very many other situations. (In answer to this question in the past, I've had techie types dismiss it as a problem with the data: your data is faulty!)
e.g., in a composer catalogue you are recording the fact that the composer dated a manuscript "January 1951". What can you put in a MySQL DATE field to represent this? "1951-01"? "1951-01-00"? Neither is really valid. Normally you end up encoding years, months and days in separate fields and then having to implement the semantics at application level. This is far from ideal.
If you're doing analytics against a fixed range of dates consider using a date dimension (fancy name for table) and use a foreign key into the date dimension. Check out this link:
http://www.ipcdesigns.com/dim_date/
If you use this date dimension consider how easily it will be to construct queries against any kind of dates you can think of.
SELECT * FROM my_table
JOIN DATE_DIM date on date.PK = my_table.date_FK
WHERE date.day = 30 AND
date.month = 1 AND
date.year = 2010
Or
SELECT * FROM my_table
JOIN DATE_DIM date on date.PK = my_table.date_FK
WHERE date.day_of_week = 1 AND
date.month = 1 AND
date.year = 2010
Or
SELECT *, date.day_of_week_name FROM my_table
JOIN DATE_DIM date on date.PK = my_table.date_FK
WHERE date.is_US_civil_holiday = 1
How would I go about doing a query that returns results of all rows that contain dates for current year and month at the time of query.
Timestamps for each row are formated as such: yyyy-mm-dd
I know it probably has something to do with the date function and that I must somehow set a special parameter to make it spit out like such: yyyy-mm-%%.
Setting days to be wild card character would do the trick but I can't seem to figure it out how to do it.
Here is a link to for quick reference to date-time functions in mysql:
http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html
Thanks
I think EXTRACT is the function you are looking for:
SELECT * FROM table
WHERE EXTRACT(YEAR_MONTH FROM timestamp_field) = EXTRACT(YEAR_MONTH FROM NOW())
you could extract the year and month using a function, but that will not be able to use an index.
if you want scalable performance, you need to do this:
SELECT *
FROM myTable
WHERE some_date_column BETWEEN '2009-01-01' AND '2009-01-31'
select * from someTable where year(myDt) = 2009 and month(myDt) = 9 and day(myDt) = 12