I was just wondering how would I go about checking to see if, for example, a booking is due within 24 hours?
My bookings table will have the important fields that may help in finding the solution: studiono, title, date, time, hour
At the moment, I have tried the following:
select StudioNo
from Bookings
where sysdate - "DATE" <1
and "TIME" - trunc("Time") + trunc(systimestamp) > systimestamp;
However, I don't think this works. Am I doing this correctly?
Any help is appreciated.
Without knowing what your database structure is:
select StudioNo
from Bookings
where to_date(date || time, 'dd-mon-yyyyhh24:mi:ss') < sysdate +1
and to_date(date || time, 'dd-mon-yyyyhh24:mi:ss') > sysdate
basically, create a single date/time field from your 2 seperate date and time columns (which I'm assuming here are strings), and then compare that to sysdate + 1
Firstly, is there any particular reason why your Bookings table has separate columns for date and time? The Oracle datatype DATE will include both of these in a single column. This will then make the required query much more straight forward:
SELECT StudioNo
FROM Bookings
WHERE BookingDate BETWEEN SYSDATE AND SYSDATE+1;
Related
Hello I have table "os_txn.pay_link" and inside there are many columns.
What I want to do is that I want to count the row numbers by looking at "merchant_id" column for the current day.
So for example what I am looking for an output is that today one of "merchant_id" has
"8" rows. So I want to know the number of rows of the "merchant_id" column for current day.
I think I should use count(*) in view with select statement but couldnt succeed about syntax. So I am open your suggestions thank you.
If I understood you correctly, a simple option would be
select merchant_id, count(*)
from os_txn.pay_link
where date_column = trunc(sysdate)
group by merchant_id;
presuming that date_column contains date only (i.e. for today, 8th of October 2022, that's its value - no hours, minutes or seconds).
If date column contains time component, again - a simple option - would be
select merchant_id, count(*)
from os_txn.pay_link
where trunc(date_column) = trunc(sysdate)
group by merchant_id;
If there's an index on date_column, then such a code wouldn't use it (unless it is a function-based index) so you'd rather modify it to
where date_column >= trunc(sysdate)
and date_column < trunc(sysdate + 1)
If that's not it, do post sample data and desired result.
I have the following query that joins two large tables. I am trying to join on patient_id and records that are not older than 30 days.
select * from
chairs c
join data id
on c.patient_id = id.patient_id
and to_date(c.from_date, 'YYYYMMDD') - to_date(id.from_date, 'YYYYMMDD') >= 0
and to_date (c.from_date, 'YYYYMMDD') - to_date(id.from_date, 'YYYYMMDD') < 30
Currently, this query takes 2 hours to run. What indexes can I create on these tables for this query to run faster.
I will take a shot in the dark, because as others said it depends on what the table structure, indices, and the output of the planner is.
The most obvious thing here is that as long as it is possible, you want to represent dates as some date datatype instead of strings. That is the first and most important change you should make here. No index can save you if you transform strings. Because very likely, the problem is not the patient_id, it's your date calculation.
Other than that, forcing hash joins on the patient_id and then doing the filtering could help if for some reason the planner decided to do nested loops for that condition. But that is for after you fixed your date representation AND you still have a problem AND you see that the planner does nested loops on that attribute.
Some observations if you are stuck with string fields for the dates:
YYYYMMDD date strings are ordered and can be used for <,> and =.
Building strings from the data in chairs to use to JOIN on data will make good use of an index like one on data for patient_id, from_date.
So my suggestion would be to write expressions that build the date strings you want to use in the JOIN. Or to put it another way: do not transform the child table data from a string to something else.
Example expression that takes 30 days off a string date and returns a string date:
select to_char(to_date('20200112', 'YYYYMMDD') - INTERVAL '30 DAYS','YYYYMMDD')
Untested:
select * from
chairs c
join data id
on c.patient_id = id.patient_id
and id.from_date between to_char(to_date(c.from_date, 'YYYYMMDD') - INTERVAL '30 DAYS','YYYYMMDD')
and c.from_date
For this query:
select *
from chairs c join data
id
on c.patient_id = id.patient_id and
to_date(c.from_date, 'YYYYMMDD') - to_date(id.from_date, 'YYYYMMDD') >= 0 and
to_date (c.from_date, 'YYYYMMDD') - to_date(id.from_date, 'YYYYMMDD') < 30;
You should start with indexes on (patient_id, from_date) -- you can put them in both tables.
The date comparisons are problematic. Storing the values as actual dates can help. But it is not a 100% solution because comparison operations are still needed.
Depending on what you are actually trying to accomplish there might be other ways of writing the query. I might encourage you to ask a new question, providing sample data, desired results, and a clear explanation of what you really want. For instance, this query is likely to return a lot of rows. And that just takes time as well.
Your query have a non SERGABLE predicate because it uses functions that are iteratively executed. You need to discard such functions and replace them by a direct access to the columns. As an exemple :
SELECT *
FROM chairs AS c
JOIN data AS id
ON c.patient_id = id.patient_id
AND c.from_date BETWEEN id.from_date AND id.from_date + INTERVAL '1 day'
Will run faster with those two indexes :
CREATE X_SQLpro_001 ON chairs (patient_id, from_date);
CREATE X_SQLpro_002 ON data (patient_id, from_date) ;
Also try to avoid
SELECT *
And list only the necessary columns
i know this query is not right, and kind of jumbled. but it sort of displays what i want to do. what I'm trying to figure out is how to use the current date in a query. basically i want to subtract a stored date from the current date and if the result is < 30 do something. but i obviously don't know how to work with dates.... i am assuming that it shouldn't be a char value, but if i just use sys date oracle gives me a table error.
select e.STUDENT_ID
from COURSES c, CLASS_ENROLLMENT e, (SELECT TO_CHAR (SYSDATE, 'MM-DD-YYYY') as now
FROM DUAL) t
where t - c.END_DATE <= 30;
Assuming the rest of your query is correct this should solve your date problem:
select e.STUDENT_ID
from COURSES c, CLASS_ENROLLMENT e
where to_date(to_char(sysdate, 'DD-MON-RR')) - c.END_DATE <= 30;
You don't need to select sysdate from dual unless you just want to display it for one reason or another without querying something else. You can just specify it as sysdate as part of a any query anywhere.
The reason I converted it to a character and then to a date in this case is just to remove the time from sysdate, this way it will be 30 days from the given day, regardless of time. If you didn't care about time you could just say sysdate - c.end_date <=30
As an fyi - you probably need to add join conditions between the COURSES and CLASS_ENROLLMENT tables. The above should not result in a sql error and should do you want with respect to the date of the records, but it's unlikely to be what you want (in full).
I would like to ask how do i check if the difference between two dates.
BillingDate which is a date type with an entry 'DD-MON-YYYY'
and the other date is the current date.
sys_date - BillingDate = daysFromBilled
alot of the examples i find they actually stated the second date to calculate the difference but what i am looking for is the difference between the current date so i can add it into a schedule or job.
i am using oracle btw.
Another point to add, i will continue to search, but if your could also recommend, how should i implement such a function:
Calculate date difference from all BillingDate entries
To trigger an alter table if the difference is more than 30 days to put Status as Late.
If Status is more than 60 days the Service attribute will be altered and changed to Cut
here is my rough table layout
Cust Billing
-------- ----------
CustID(PK) BillingID(PK)
LateStatus LateStatus
Service BillingDate
CustID
Thanks alot.
Update
REPLACE view DateDifference as
select trunc(sysdate)- trunc(BillingDate)
from Billing;
seems legit.
Simply subtract one date from the other:
BillingDate - sysdate
To do that in a select statement, just use it like this:
select billingdate - sysdate as daysFromBilled
from ...
Inside a trigger you use a regular assignment operator:
declare
daysFromBilled integer;
begin
daysFromBilled := :new.billingdate - sysdate;
...
that will return the number of days, including fractional values if the time is different (a DATE column in Oracle also contains a time!).
If you only want to get full days, use this:
trunc(BillingDate) - trunc(sysdate)
This statement of yours:
date type with an entry 'DD-MON-YYYY'
Indicates a misunderstanding on how DATE values work.
A DATE (or TIMESTAMP) does not have any format.
They are stored in binary form in your column. The format is only applied when you display the value and thus convert it to a character literal. That is the work of the client application you use to display the values. SQL*Plus uses the NLS settings, other SQL tools might use a different configuration.
All customers:
SELECT CUSTID
FROM BILLING
WHERE (SYSDATE - Billing_Date) >= 60
;
The following statement should update all the customer records where the difference is 60 days and over. Also, have added a clause to check if the service is already not set to CUT previously, so you don't end up updating the same records everytime.
UPDATE CUST_TABLE
SET SERVICE = 'CUT'
WHERE CustID in ( SELECT CustID
FROM BILLING_TABLE
WHERE (Sysdate - Billing_Date) >= 60
)
AND NVL(SERVICE, 'X') != 'CUT'
;
I'm trying to model a DateRange concept for a reporting application. Some date ranges need to be absolute, March 1, 2011 - March 31, 2011. Others are relative to current date, Last 30 Days, Next Week, etc. What's the best way to store that data in SQL table?
Obviously for absolute ranges, I can have a BeginDate and EndDate. For relative ranges, having an InceptionDate and an integer RelativeDays column makes sense. How do I incorporate both of these ideas into a single table without implementing context into it, ie have all four columns mentioned and use XOR logic to populate 2 of the 4.
Two possible schemas I rejected due to having context-driven columns:
CREATE TABLE DateRange
(
BeginDate DATETIME NULL,
EndDate DATETIME NULL,
InceptionDate DATETIME NULL,
RelativeDays INT NULL
)
OR
CREATE TABLE DateRange
(
InceptionDate DATETIME NULL,
BeginDaysRelative INT NULL,
EndDaysRelative INT NULL
)
Thanks for any advice!
I don't see why your second design doesn't meet your needs unless you're in the "no NULLs never" camp. Just leave InceptionDate NULL for "relative to current date" choices so that your application can tell them apart from fixed date ranges.
(Note: not knowing your DB engine, I've left date math and current date issues in pseudocode. Also, as in your question, I've left out any text description and primary key columns).
Then, either create a view like this:
CREATE VIEW DateRangesSolved (Inception, BeginDays, EndDays) AS
SELECT CASE WHEN Inception IS NULL THEN Date() ELSE Inception END,
BeginDays,
EndDays,
FROM DateRanges
or just use that logic when you SELECT from the table directly.
You can even take it one step further:
CREATE VIEW DateRangesSolved (BeginDate, EndDate) AS
SELECT (CASE WHEN Inception IS NULL THEN Date() ELSE Inception END + BeginDays),
(CASE WHEN Inception IS NULL THEN Date() ELSE Inception END + EndDays)
FROM DateRanges
Others are relative to current date, Last 30 Days, Next Week, etc.
What's the best way to store that data in SQL table?
If you store those ranges in a table, you have to update them every day. In this case, you have to update each row differently every day. That might be a big problem; it might not.
There usually aren't many rows in that kind of table, often less than 50. The table structure is obvious. Updating should be driven by a cron job (or its equivalent), and you should run very picky exception reports every day to make sure things have been updated correctly.
Normally, these kinds of reports should produce no output if things are fine. You have the added complication that driving such a report from cron will produce no output if cron isn't running. And that's not fine.
You can also create a view, which doesn't require any maintenance. With a few dozen rows, it might be slower than a physical table, but it might still fast enough. And it eliminates all maintenance and administrative work for these ranges. (Check for off-by-one errors, because I didn't.)
create view relative_date_ranges as
select 'Last 30 days' as range_name,
(current_date - interval '30' day)::date as range_start,
current_date as range_end
union all
select 'Last week' as range_name,
(current_date - interval '7' day)::date as range_start,
current_date as range_end
union all
select 'Next week' as range_name,
(current_date + interval '7' day)::date as range_start,
current_date as range_end
Depending on the app, you might be able to treat your "absolute" ranges the same way.
...
union all
select 'March this year' as range_name,
(extract(year from current_date) || '-03-01')::date as range_start,
(extract(year from current_date) || '-03-31')::date as range_end
Put them in separate tables. There is absolutely no reason to have them in a single table.
For the relative dates, I would go so far as to simply make the table the parameters you need for the date functions, i.e.
CREATE TABLE RelativeDate
(
Id INT Identity,
Date_Part varchar(25),
DatePart_Count int
)
Then you can know that it is -2 WEEK or 30 DAY variance and use that in your logic.
If you need to see them both at the same time, you can combine them LOGICALLY in a query or view without needing to mess up your data structure by cramming different data elements into the same table.
Create a table containing the begindate and the offset. The precision of the offset is up to you to decide.
CREATE TABLE DateRange(
BeginDate DATETIME NOT NULL,
Offset int NOT NULL,
OffsetLabel varchar(100)
)
to insert into it:
INSERT INTO DateRange (BeginDate, Offset, OffsetLabel)
select '20110301', DATEDIFF(sec, '20110301', '20110331'), 'March 1, 2011 - March 31, 2011'
Last 30 days
INSERT INTO DateRange (BeginDate, Duration, OffsetLabel)
select '20110301', DATEDIFF(sec, current_timestamp, DATEADD(day, -30, current_timestamp)), 'Last 30 Days'
To display the values later:
select BeginDate, EndDate = DATEADD(sec, Offset, BeginDate), OffsetLabel
from DateRange
If you want to be able to parse the "original" vague descriptions you will have to look for a "Fuzzy Date" or "Approxidate" function. (There exists something like this in the git source code. )