I have a large database with a column containing timestamps (date/time). Some records were inserted with the time being exactly midnight (no milliseconds). I want a query that will return all records from the table regardless of date, that have a time of midnight.
I know how to create a record with timestamp of midnight, but don't know how to specifically search for them.
select TRUNC(SYSDATE) FROM DUAL;
You can compare the column value with the truncated value:
where datetimecol = trunc(datetimecol)
Related
I am running the below query to get data recorded in the past 24 hours. I need the same data recorded starting midnight (DATE > 12:00 AM) and also data recorded starting beginning of the month. Not sure if using between will work or if there is better option. Any suggestions.
SELECT COUNT(NUM)
FROM TABLE
WHERE
STATUS = 'CNLD'
AND
TRUNC(TO_DATE('1970-01-01','YYYY-MM-DD') + OPEN_DATE/86400) = trunc(sysdate)
Output (Just need Count). OPEN_DATE Data Type is NUMBER. the output below displays count in last 24 hours. I need the count beginning midnight and another count starting beginning of the month.
The query you've shown will get the count of rows where OPEN_DATE is an 'epoch date' number representing time after midnight this morning*. The condition:
TRUNC(TO_DATE('1970-01-01','YYYY-MM-DD') + OPEN_DATE/86400) = trunc(sysdate)
requires every OPEN_DATE value in your table (or at least all those for CNLD rows) to be converted from a number to an actual date, which is going to be doing a lot more work than necessary, and would stop a standard index against that column being used. It could be rewritten as:
OPEN_DATE >= (trunc(sysdate) - date '1970-01-01') * 86400
which converts midnight this morning to its epoch equivalent, once, and compares all the numbers against that value; using an index if there is one and the optimiser thinks it's appropriate.
To get everything since the start of the month you could just change the default behaviour of trunc(), which is to truncate to the 'DD' element, to truncate to the start of the month instead:
OPEN_DATE >= (trunc(sysdate, 'MM') - date '1970-01-01') * 86400
And the the last 24 hours, subtract a day from the current time instead of truncating it:
OPEN_DATE >= ((sysdate - 1) - date '1970-01-01') * 86400
db<>fiddle with some made-up data to get 72 back for today, more for the last 24 hours, and more still for the whole month.
Based on your current query I'm assuming there won't be any future-dated values, so you don't need to worry about an upper bound for any of these.
*Ignoring leap seconds...
It sounds like you have a column that is of data type TIMESTAMP and you only want to select rows where that TIMESTAMP indicates that it is today's date? And as a related problem, you want to find those that are the current month, based on some system values like CURRENT TIMESTAMP and CURRENT DATE? If so, let's call your column TRANSACTION_TIMESTAMP instead of (reserved word) DATE. Your first query could be:
SELECT COUNT(NUM)
FROM TABLE
WHERE
STATUS = 'CLND'
AND
DATE(TRANSACTION_TIMESTAMP)=CURRENT DATE
The second example of finding all for the current month up to today's date could be:
SELECT COUNT(NUM)
FROM TABLE
WHERE
STATUS = 'CLND'
AND
YEAR(DATE(TRANSACTION_TIMESTAMP)=YEAR(CURRENT DATE) AND
MONTH(DATE(TRANSACTION_TIMESTAMP)=MONTH(CURRENT DATE) AND
DAY(DATE(TRANSACTION_TIMESTAMP)<=DAY(CURRENT DATE)
I want to create a query in Oracle SQL that will grab records from a given time interval, during certain hours of the day, e.g. records between 10am to noon, in the past 10 days. I tried this, but it does not work:
select * from my_table where timestamp between
to_timestamp('2020-12-30','YYYY-MM-DD')
and
to_timestamp('2021-01-08','YYYY-MM-DD') and
timestamp between
to_timestamp('10:00:00','HH24:MI:SS')
and
to_timestamp('12:00:00','HH24:MI:SS')
where timestamp is of type TIMESTAMP. I have also thought of using a join, but I am struggling to find a way to filter on time of day.
Is there a way to filter using only the time, not the date, or a way to filter on time for every day in the interval?
select *
from my_table
where timestamp between to_timestamp('2020-12-30','YYYY-MM-DD')
and to_timestamp('2021-01-08','YYYY-MM-DD')
and timestamp - trunc(timestamp) between interval '10' hour
and interval '12' hour
If you don't need to include exactly noon (including no fractional seconds), you could also do
select *
from my_table
where timestamp between to_timestamp('2020-12-30','YYYY-MM-DD')
and to_timestamp('2021-01-08','YYYY-MM-DD')
and extract( hour from timestamp ) between 10 and 11
As an aside, I'd hope that your actual column name isn't timestamp. It's legal as a column name but it is a reserved word so you're generally much better off using a different name.
I'm trying to retrieve data for a specific date with query:
Select * from table_1 where activity_date = to_date('13-09-2017','DD-MM-YYYY');
But I'm not getting any result.
But when I query below:
Select * from table_1 where activity_date >= to_date('13-09-2017','DD-MM-YYYY');
I'm getting the data for days greater than equal to 13-09-2017.
Any help?
It seems the data type of your column is Date Time and hence when you are querying with just date (13-09-2017), it searching for date as well as time (13-09-2017 00:00:00). Seems there are no record in your database with this exact date time stamp and hence no results are being returned. Below query will work in your case:
SELECT *
FROM table_1
WHERE activity_date >= to_date('13-09-2017','DD-MM-YYYY')
AND activity_date < to_date('14-09-2017','DD-MM-YYYY');
When you compare dates remember that you usually compare some kind of a timestamp. A timestamp usually also has hours, minutes, seconds etc. So in your database you probably have a whole timestamp like '13-09-2017' + specific hour, minutes and so on, whilst to_date explicitly only formats your DD MM and YYYY causing the hour, minutes and seconds to be equal to 0. The query is probably not returning any records as you probably don't have a date with the exact time equal to 00:00:00.
That's also why a comparison like >= will return results. Because your '13-09-2017' database entries are all greater than '13-09-2017' (with hour equal to 00:00:00) because they all have some hours, minutes and seconds to them, for e.g 13-09-2017 04:02:45 which is greater than 13-09-2017 00:00:00).
How to solve this? Well for example:
SELECT *
FROM table_1
WHERE activity_date >= to_date('13-09-2017','DD-MM-YYYY')
AND activity_date < to_date('14-09-2017','DD-MM-YYYY')
I have below TEMP_PROCESS_MONITOR table which has ALERT_TIMESTAMP column which has date data type.The TIMEOUT column has Number data type and it consist of Minutes values. I want to subtract the Current date with the ALERT_TIMESTAMP field and get the minutes and then compare this minutes with TIMEOUT field in the below select query.
TEMP_PROCESS_MONITOR table:
And the condition should be for example like this:
(CURRENT_TIMESTMAP - ALERT_TIMESTAMP) > TIMEOUT
So i have to remove the Where condition from the below query and put the condition which i have mentioned above:
SELECT COUNT(*) FROM TEMP_PROCESS_MONITOR WHERE IS_DOWN = 1;
To get current date with seconds in date format you may use SYSDATE SQL function.
Date subtraction gives number of days (with fraction) as a result.
So you need either translate this number to minutes:
(SYSDATE - ALERT_TIMESTAMP)*24*60 > TIMEOUT
or translate timeout to days:
(SYSDATE - ALERT_TIMESTAMP) > TIMEOUT/(24*60)
I have a PostgreSQL database in which one table rapidly grows very large (several million rows every month or so) so I'd like to periodically archive the contents of that table into a separate table.
I'm intending to use a cron job to execute a .sql file nightly to archive all rows that are older than one month into the other table.
I have the query working fine, but I need to know how to dynamically create a timestamp of one month prior.
The time column is stored in the format 2013-10-27 06:53:12 and I need to know what to use in an SQL query to build a timestamp of exactly one month prior. For example, if today is October 27, 2013, I want the query to match all rows where time < 2013-09-27 00:00:00
Question was answered by a friend in IRC:
'now'::timestamp - '1 month'::interval
Having the timestamp return 00:00:00 wasn't terrible important, so this works for my intentions.
select date_trunc('day', NOW() - interval '1 month')
This query will return date one month ago from now and round time to 00:00:00.
When you need to query for the data of previous month, then you need to query for the respective date column having month values as (current_month-1).
SELECT *
FROM {table_name}
WHERE {column_name} >= date_trunc('month', current_date-interval '1' month)
AND {column_name} < date_trunc('month', current_date)
The first condition of where clause will search the date greater than the first day (00:00:00 Day 1 of Previous Month)of previous month and second clause will search for the date less than the first day of current month(00:00:00 Day 1 of Current Month).
This will includes all the results where date lying in previous month.