Comparing start dates and end dates using SQL in SAS - sql

I'm trying to compare start dates and end dates to make sure that start dates aren't later than end dates.
Tried posting onto sas community website, but too many post restrictions errors
table:
start_date
1-Mar-19
I have included the proc sql/quit thing, but it gives me "ERROR: Function SUBSTRING_INDEX could not be located."
SELECT SUBSTRING_INDEX(start_date, '-', 1) AS day
, SUBSTRING_INDEX(SUBSTRING_INDEX(start_date, '-', 2), '-',-1) as month
, SUBSTRING_INDEX(start_date, '-', -1) as year
FROM mylib.sheet1
;
Thanks

If you have date variables just compare the values.
start_date <= end_date
If you have strings instead of dates then first convert them into date values. Then you can compare them.
input(start_string,date9.) <= input(end_string,date9.)

Related

Get first day of first month of previous year in yyyy-mm-dd format

How do I get the first day of the first month of previous year in yyyy-mm-dd format? ie. 2019-01-01.
This is the code I have tried:
SELECT DATEADD(yy,-1,DATEADD(yy,DATEDIFF(yy,0,GETDATE()),0))
You can use DATEFROMPARTS() function in SQL Server for creating date from given year, month and date in integer as shown below. To get the previous year you can use Year() function and subtract 1 from that. First date and month is always 1 so it has been hard-coded here.
declare #IntYear int = Year(Getdate()) - 1 --Previous Year
Select datefromparts(#Intyear, 1, 1)
The output in SSMS is as shown below.
To get the output in the different format you can follow this link.
You seem to be looking to generate a string, not a date. Consider using date functions and string concatenation: you just need to substract 1 year from the current date, and then append '-01-01'
concat_ws('-', year(getdate()) - 1, '01', '01')
Demo on DB Fiddle
You basically have it. You just need the FORMAT function.
SELECT FORMAT (DATEADD(yy,-1,DATEADD(yy,DATEDIFF(yy,0,GETDATE()),0)), 'yyyy-MM-dd') as date

SQL Server end of month

Suppose there is one date in int format 20191229, I want to find end of month and check if it's end of month is of 31 days or 30 days in SQL Server
You can try this from the reference. The given answer will not work for the integer data type but it will work in the varchar datatype date value. Storing Date values in integer is not a good idea, so as suggested by Larnu change the data type in either date or varchar.
SELECT
Day(EOMONTH(Cast('20191229' as Date))) end_of_month;
If you want the amount of days within a month, as you need the days as an integer, you should go for this. This is the most robust built, but also the more complex one, as to make sure the Integer value is processed correctly:
SELECT DATEPART(DAY,EOMONTH(CAST(CAST('20191229' AS NCHAR(8)) AS DATE))) AS Days
Result:
Days
31
If you want to add an IF evaluation to your selected date(s), you can do this by add an IIF-clause where it evaluates whether or not the end of month is 31 or not. If you want to use a columnname instead of the date, just substitute #Date with the columnname. I've just added the variable #Date instead of '20191229' to make it more illustrative/understandable. You can change the True/false descriptions to whatever you like in the query.
DECLARE #Date AS int
SET #Date = '20191229'
SELECT
IIF (
DATEPART(DAY,EOMONTH(CAST(CAST(#Date AS NCHAR(8)) AS DATE))) = '31'
,'True'
,'False'
) AS Days
Output:
Days
True

Find data with specific date and month only

I am trying to find a data with specific where clause of date and month but I am receiving an error can anyone help me with this?
select *
from my_data
where date BETWEEN '11-20' AND '12-15'
MS SQL Server Management Studio
I am receving an error
Conversion failed when converting date and/or time from character string
Most databases support functions to extract components of dates. So, one way of doing what you want is to convert the values to numbers and make a comparison like this:
where month(date) * 100 + day(date) between 1120 and 1215
The functions for extracting date parts differ by database, so your database might have somewhat different methods for doing this.
The conversion is failing because you are not specifying a year. If you were to specify '11-20-2015' your query would work just insert whatever year you need.
SELECT *
FROM my_data
WHERE date BETWEEN '11-20-2015' AND '12-15-2015'
Alternatively if you wanted data from that range of dates for multiple years I would use a while loop to insert information in a # table then read from that table, depending on the amount of data this could be quick or sloooowww here is an example.
DECLARE #mindatestart date, #mindateend date, #maxdatestart date
SET #mindatestart = '11-20-2010'
SET #mindateend = '12-15-2010'
SET #maxdatestart = '11-20-2015'
SELECT top 0 *, year = ' '
INTO #mydata
FROM my_data
WHILE #mindatestart < #maxdatestart
BEGIN
INSERT INTO #mydata
SELECT *, YEAR(#mindatestart)
FROM my_data
where date between #mindatestart and #mindateend
SET #mindatestart = DATEADD(Year, 1, #mindatestart)
SET #mindateend = DATEADD(Year, 1, #mindateend)
END
This will loop and insert the data from 2010-2015 for those date ranges and add a extra column on the end so you can call the data and order by year if you want like this
SELECT * FROM #mydata order by YEAR
Hopefully some part of this helps!
FROM THE COMMENT BELOW
SELECT *
FROM my_data
WHERE DAY(RIGHT(date, 5)) between DAY(11-20) and DAY(12-15)
The reason '11-20' doesn't work is because its a character string which is why you have to input it between ' ' What the Month() function does is take whatever you put between the () and convert it to an integer. Which is why you're not getting anything back using the method in the first answer, the '-Year' from the table date field is being added into the numeric value where your value is just being converted from 11-20 you can see by using these queries
SELECT MONTH(11-20) --Returns 12
SELECT MONTH(11-20-2015) -- Returns 6
SELECT MONTH(11-20-2014) -- Returns 6
Using RIGHT(Date, 5) you only get Month-day, then you date the day value of that so DAY(RIGHT(DATE, 5) and you should get something that in theory should fall within those date ranges despite the year. However I'm not sure how accurate the data will be, and its a lot of work just to not add an additional 8 characters in your original query.
Since you only care about month and day, but not year, you need to use DATEPART to split up the date. Try this:
select *
from my_data
WHERE 1=1
AND (DATEPART(m, date) >= 11 AND DATEPART(d,date) >= 20)
AND (DATEPART(m, date) <= 12 AND DATEPART(d,date) <= 15)

Selecting YYYYMM of the previous month in HIVE

I am using Hive, so the SQL syntax might be slightly different. How do I get the data from the previous month? For example, if today is 2015-04-30, I need the data from March in this format 201503? Thanks!
select
employee_id, hours,
previous_month_date--YYYYMM,
from
employees
where
previous_month_date = cast(FROM_UNIXTIME(UNIX_TIMESTAMP(),'yyyy-MM-dd') as int)
From experience, it's safer to use DATE_ADD(Today, -1-Day(Today)) to compute last-day-of-previous-month without having to worry about edge cases. From there you can do what you want e.g.
select
from_unixtime(unix_timestamp(), 'yyyy-MM-dd') as TODAY,
date_add(from_unixtime(unix_timestamp(), 'yyyy-MM-dd'), -1-cast(from_unixtime(unix_timestamp(), 'd') as int)) as LAST_DAY_PREV_MONTH,
substr(date_add(from_unixtime(unix_timestamp(), 'yyyy-MM-dd'), -1-cast(from_unixtime(unix_timestamp(), 'd') as int)), 1,7) as PREV_MONTH,
cast(substr(regexp_replace(date_add(from_unixtime(unix_timestamp(), 'yyyy-MM-dd'), -1-cast(from_unixtime(unix_timestamp(), 'd') as int)), '-',''), 1,6) as int) as PREV_MONTH_NUM
from WHATEVER limit 1
-- today last_day_prev_month prev_month prev_month_num
-- 2015-08-13 2015-07-30 2015-07 201507
See Hive documentation about date functions, string functions etc.
below works across year boundaries w/o complex calcs:
date_format(add_months(current_date, -1), 'yyyyMM') --previous month's yyyyMM
in general,
date_format(add_months(current_date, -n), 'yyyyMM') --previous n-th month's yyyyMM
use proper sign for needed direction (back/ahead)
You could do (year('2015-04-30')*100+month('2015-04-30'))-1 for the above mentioned date, it will return 201503 or something like (year(from_unixtime(unix_timestamp()))*100+month(from_unixtime(unix_timestamp())))-1 for today's previous month. Assuming your date column is in 'yyyy-mm-dd' format you can use the first example and substitute the date string with your table column name; for any other format the second example will do, add the column name in the unix_timestamp() operator.
Angelo's reply is a good start but it returns 201500 if the original date was 2015-01-XX. Building on his answer, I suggest using the following:
IF(month(${DATE}) = 1,
(year(${DATE})-1)*100 + 12,
year(${DATE})*100 + month(${DATE})-1
) as month_key
provided you get rid of those hyphens in your input string , previous date's month id in YYYYMM format you can get by:-
select if( ((${hiveconf:MonthId}-1)%100)=0 ,${hiveconf:MonthId}-89,${hiveconf:MonthId}-1 ) as PreviousMonthId;

Date arithmetic in SQL on DB2/ODBC

I'm building a query against a DB2 database, connecting through the IBM Client Access ODBC driver. I want to pull fields that are less than 6 days old, based on the field 'a.ofbkddt'... the problem is that this field is not a date field, but rather a DECIMAL field, formatted as YYYYMMDD.
I was able to break down the decimal field by wrapping it in a call to char(), then using substr() to pull the year, month and day fields. I then formatted this as a date, and called the days() function, which gives a number that I can perform arithmetic on.
Here's an example of the query:
select
days( current date) -
days( substr(char(a.ofbkddt),1,4) concat '-' -- YYYY-
concat substr(char(a.ofbkddt),5,2) concat '-' -- MM-
concat substr(char(a.ofbkddt),7,2) ) as difference, -- DD
a.ofbkddt as mydate
from QS36F.ASDF a
This yields the following:
difference mydate
2402 20050402
2025 20060306
...
4 20110917
3 20110918
2 20110919
1 20110920
This is what I expect to see... however when I use the same logic in the where clause of my query:
select
days( current date) -
days( substr(char(a.ofbkddt),1,4) concat '-' -- YYYY-
concat substr(char(a.ofbkddt),5,2) concat '-' -- MM-
concat substr(char(a.ofbkddt),7,2) ) as difference, -- DD
a.ofbkddt as mydate
from QS36F.ASDF a
where
(
days( current date) -
days( substr(char(a.ofbkddt),1,4) concat '-' -- YYYY-
concat substr(char(a.ofbkddt),5,2) concat '-' -- MM
concat substr(char(a.ofbkddt),7,2) ) -- DD
) < 6
I don't get any results back from my query, even though it's clear that I am getting date differences of as little as 1 day (obviously less than the 6 days that I'm requesting in the where clause).
My first thought was that the return type of days() might not be an integer, causing the comparison to fail... according to the documentation for days() found at http://publib.boulder.ibm.com/iseries/v5r2/ic2924/index.htm?info/db2/rbafzmst02.htm, it returns a bigint. I cast the difference to integer, just to be safe, but this had no effect.
You're going about this backwards. Rather than using a function on every single value in the table (so you can compare it to the date), you should pre-compute the difference in the date. It's costing you resources to run the function on every row - you'd save a lot if you could just do it against CURRENT_DATE (it'd maybe save you even more if you could do it in your application code, but I realize this might not be possible). Your dates are in a sortable format, after all.
The query looks like so:
SELECT ofbkddt as myDate
FROM QS36F.ASDF
WHERE myDate > ((int(substr(char(current_date - 6 days, ISO), 1, 4)) * 10000) +
(int(substr(char(current_date - 6 days, ISO), 6, 2)) * 100) +
(int(substr(char(current_date - 6 days, ISO), 9, 2))))
Which, when run against your sample datatable, yields the following:
myDate
=============
20110917
20110918
20110919
20110920
You might also want to look into creating a calendar table, and add these dates as one of the columns.
What if you try a common table expression?
WITH A AS
(
select
days( current date) -
days( substr(char(a.ofbkddt),1,4) concat '-' -- YYYY-
concat substr(char(a.ofbkddt),5,2) concat '-' -- MM-
concat substr(char(a.ofbkddt),7,2) ) as difference, -- DD
a.ofbkddt as mydate
from QS36F.ASDF a
)
SELECT
*
FROM
a
WHERE
difference < 6
Does your data have some nulls in a.ofbkddt? Maybe this is causing some funny behaviour in how db2 is evaluating the less than operation.