I'm trying to exclude results in my query that start in the same month between two columns. For example, I need to exclude benefits1 that start in the same month as benefits2. Format for benefit1_start_date and benefit2_start_date is: YYYYMMDD.
This is what I have so far:
where (benefit1_start_date = (to_char(sysdate, 'YYYYMM') || '0122')) <>
(benefit2_start_date = (to_char(sysdate, 'YYYYMM') || '0122'));
If anyone could put me in the right direction, I'd greatly appreciate it!
Convert your numeric dates to text, and then compare the year and month substrings:
WHERE
SUBSTR(TO_CHAR(benefits1_start_date), 1, 6) <> SUBSTR(TO_CHAR(benefits2_start_date), 1, 6)
Note that storing your dates as numbers like this is atypical, and you might want to consider storing them as dates. If you don't have a day component, you could just use the first as a placeholder.
As I understand it, you want to eliminate records where your 2 columns benefits1_start_date and benefits2_start_date are in the same month, and both have a format of YYYYMMDD.
Are they stored as strings? If so, all you need to do is compare the first 6 characters (if you need to consider yr + month), or just the 5+6th characters if you want to check just the month without the year.
Year + Month:
SUBSTR(benefits1_start_date,1,6) <> SUBSTR(benefits2_start_date,1,6)
Just month:
SUBSTR(benefits1_start_date,5,2) <> SUBSTR(benefits2_start_date,5,2)
If they're not stored as strings but as dates, then you can TRUNC the date to month and compare (for yr + month), or convert the date to MM string via to_char and compare if you just want to check the month.
Hope this helps.
I suggest you to use BETWEEN clause. Converting LEFT side operand to string by function and then making comparison can have severe performance impacts.
if you convert indexed table.dateColumn to string by to_char(table.dateColumn), oracle cannot use defined index on column anymore.
Your desired query:
where to_char(benefit1_start_date, 'YYYYMM') != to_char(benefit2_start_date, 'YYYYMM')
but
select * from table1
where months_between(benefit1_start_date, benefit2_start_date) not between -1 and 1
would be what you are looking for. (no performance impact)
Related
Select * from dual where between to_date(date,'YYYY-MM-DD') = '2020-10-01'
and to_date(date,'YYYY-MM-DD') + 5
this is correct way to write query?
1.format of date is varchar2
2.required data between current date and next 5 days
3.first needs to convert into date format.
4. next 5 should be +5 in current day
You probably meant to write:
where to_date(mydate, 'yyyy-mm-dd') between trunc(sysdate)
and trunc(sysdate) + 5
Rationale:
date is a reserved word; I assume that's not the actual name of your column, so I used something else; if that's the real name, then you need to surround it with double quotes ("date", or "DATE", or else, depending on how it was initially defined)
mydate is a string so you need to turn it to a date: for this, you can use to_date()
you then compare it to the current date, without the time portion : trunc(sysdate), and the same date 5 days later
Note, however, that this would be more efficiently expressed as follows:
where mydate between to_char(trunc(sysdate), 'yyyy-mm-dd')
and to_char(trunc(sysdate + 5), 'yyyy-mm-dd')
This avoids the date conversion on the string column, and instead converts the interval bounds. Here, string comparison is possible, because the format of the string you are storing allows it (it it was stored as dd-mm-yyyy' for example, this would not be possible).
Let me, however, strongly suggest to store your dates as dates rather than string. You should always use the proper datatype, for many reason, such as data integrity and efficency.
I have a table with column DATE. Date is 'dd/mm/yyyy' and I want only days. So I try with extract and return what I need, but I what using transpose for column to row.
The select statement is:
select EXTRACT (DAY FROM "DATE") DAY
from people;
Is this thing possible?
Thank you!
If you have a string, then just use the leftmost two characters:
select substr("DATE", 1, 2) as day
That said, you should not be storing dates as strings. It is wrong, wrong, wrong. You cannot use the built-in date/time functions. You cannot use inequality comparisons either. Fix your data model.
The date format doesn't matter. It is linked to your NLS local settings and this is how you see this.
To have it generic and extract DAY from the date do this:
select to_char(sysdate, 'DD') from dual;
Would return 07 since it's September 7th 2020.
I have ID_BB_SECURITY column where the date value is stored in this column for example '20190801'.
I want to get month number from this field for example for August date i want to get 8.
I tried below query but it throws an error 'literal does not match':
select to_number(to_date(ID_BB_SECURITY),'mm') from BT_EXPORT
I am not sure if i have to ignore null values so as to avoid the error
If the value is a number or string then you can convert it to a date with an appropriate mask - which is what you are missing, and what is causing the error you are getting (as it's using your session's NLS_DATE_FORMAT setting, which apparently does not match the format of the data; but which you should not rely on anyway, as #MTO said in comments):
to_date(ID_BB_SECURITY, 'YYYYMMDD')
and then extract the month number from that:
select extract(month from to_date(ID_BB_SECURITY, 'YYYYMMDD')) from BT_EXPORT
Or you could just use a substring:
select to_number(substr(ID_BB_SECURITY, 5, 2)) from BT_EXPORT;
Those assume a fixed consistent format, which is always a risky assumption when using the wrong data type. Ans if it's a number they are doing an implicit conversion from number to string, which you could turn into an explicit conversion for greater clarity.
If it's already a date - as it should be, of course - then you don't need the conversion:
select extract(month from ID_BB_SECURITY) from BT_EXPORT
If you have a number, you can use arithmetic to extract the month:
select mod(floor(20190801 / 100), 100)
from dual;
You could try converting the number date to a string, and then extracting the 5th and 6th characters:
SELECT
SUBSTR(TO_CHAR(ID_BB_SECURITY), 5, 2) AS mm
FROM BT_EXPORT;
But, it would be much better for you to use a proper date column. Then, you could use a less draconian method such as:
SELECT
TO_CHAR(ID_BB_SECURITY, 'mm') AS mm -- assuming date
FROM BT_EXPORT;
select to_number(to_char(to_date('20190801', 'yyyymmdd'), 'mm')) from dual
Try this one
select extract(month from to_date(ID_BB_SECURITY, 'YYYYMMDD')) from BT_EXPORT
This one convert number to date then extract month.
also
select extract(month from to_date('20190801', 'yyyymmdd')) from dual
Your date column has the value stored in the following format "yyyymmdd" where
yyyy is the year
mm the month
dd the day
So in order to return the number value of the month (mm) we can do as follows:
1: first transform the value from a number to a date using
to_date(20190801,'yyyymmdd')
2: get month using to_date operator
to_char( to_date(20190801,'yyyymmdd'), 'mm')
I have an integer date column "date_created" storing values like...
20180527, 20191205, 20200208
And am wondering what the best way to parse as a date is so I could do something like this in a query...
select * from table where formatted(date_created) > formatted(date_created) - 90
(to return everything within the last 90 days)
I've found some similar examples that convert from date ints representing seconds or milliseconds, but none where the columns are essentially date strings stored as integers.
Appreciate any thoughts on the best way to achieve this
And am wondering what the best way to parse as a date is so I could do something like this in a query...
You can convert "date as a number" (eg. 20180527 for May 27, 2018) using the following:
cast to varchar
parse_datetime with appropriate format
cast to date (since parse_datetime returns a timestamp)
Example:
presto> SELECT CAST(parse_datetime(CAST(20180527 AS varchar), 'yyyyMMdd') AS date);
_col0
------------
2018-05-27
However, this is not necessarily the best way to query your data. By adapting your search conditions to the format of your data (and not vice versa), you can potentially benefit from predicate push down and partition pruning. See #GordonLinoff answer for information how to do this.
You can do the comparison in the world of integers or of dates. You might as well convert the current date minus 90 days to a number:
select t.*
from t
where date_created >= cast(date_format(current_date - interval '90 day',
'%Y%m%d'
) as int
);
the below query is index friendly for any database since it does not use function on indexed column
select * from table where date_created > timestamp (formatted(date) - 90)
In addition, suppose we have date in format 20211011_1234 and we want one month older date and want back the original format, we can use the following formatting to convert date to int and vice versa.
select cast(date_format(
CAST(parse_datetime(cast(
split_part('20211011_1234', '_', 1) as varchar), 'yyyyMMdd')
AS date) - interval '30' day ,'%Y%m%d') as int) as column_name
I have one field in a Firebird DB containing dates like this
27.09.2014
untill no I compared it to the current date with
substring(100+extract(day from current_date) from 2 for 2)
|| '.' ||
substring(100+extract(month from current_date) from 2 for 2)
|| '.' ||
extract(year from current_date)
= date_field_to_compare
But now i need to keep out the greater dates and this turns out to be impossible in this case, since its not handling native dates but numbers.
So I actually need to do the opposite, to convert the
27.09.2014
into A SQL date.
Like
SELECT date_field_to_compare FROM db WHERE
date_field_to_compare < CURRENT_DATE
But how can I Convert this DB Date field into a SQL understandable date?
You shouldn't store dates in (VAR)CHAR fields, store them in a DATE. It will solve these types of problems, and make things like selecting, sorting etc a lot easier.
That said Firebird supports a number of date conversions from string, and dd.MM.yyyy is one of them:
SELECT CAST('27.09.2014' AS DATE) FROM RDB$DATABASE
Or:
SELECT date_field_to_compare
FROM db
WHERE CAST(date_field_to_compare AS DATE) < CURRENT_DATE
Related: https://stackoverflow.com/a/23857635/466862