I have a Log table and this is it's description:
user_id(bigint)
time (bigint)
My question is, how can I extract the year from the time column in PostgreSQL?
This works in MySQL:
SELECT l.user_id, year(from_unixtime(l.time))
FROM log l;
select date_part('year', to_timestamp(1365682413));
to_timestamp is our friend here and has taken a unix time since at least version 8.1.
select extract(year from timestamp 'epoch' + "time" * interval '1 second')
from log;
Related
How can I extract just the hour of a timestamp using standardSQL.
I've tried everything and no function works. The problem is that I have to extract the time from a column and this column is in the following format:2018-07-09T02:40:23.652Z
If I just put the date, it works, but if I put the column it gives the error below:
Syntax error: Expected ")" but got identifier "searchIntention" at [4:32]
Follow the query below:
#standardSQL
select TOTAL, dia, hora FROM
(SELECT cast(replace(replace(searchIntention.createdDate,'T',' '),'Z','')as
DateTime) AS DIA,
FORMAT_DATETIME("%k", DATETIME searchIntention.createdDate) as HORA,
count(searchintention.id) as Total
from `searchs.searchs2016626`
GROUP BY DIA)
Please, help me. :(
How can I extract just the hour of a timestamp using standardSQL?
Below is for BigQuery Standard SQL
You can use EXTRACT(HOUR FROM yourTimeStampColumn)
for example:
SELECT EXTRACT(HOUR FROM CURRENT_TIMESTAMP())
or
SELECT EXTRACT(HOUR FROM TIMESTAMP '2018-07-09T02:40:23.652Z')
or
SELECT EXTRACT(HOUR FROM TIMESTAMP('2018-07-09T02:40:23.652Z'))
In BigQuery Standard SQL, you can use the EXTRACT timestamp function in order to return an INT64 value corresponding to the part of the timestamp that you want to retrieve, like.
The available parts includes a full list that you can check in the documentation page linked, but in your use case you can directly refer to the HOUR operator in order to retrieve the INT64 representation of the hour value in a field of TIMESTAMP type.
#standardSQL
# Create a table
WITH table AS (
SELECT TIMESTAMP("2018-07-09T02:40:23.652Z") time
)
# Extract values from a Timestamp expression
SELECT
EXTRACT(DAY FROM time) as day,
EXTRACT(MONTH FROM time) as month,
EXTRACT(YEAR FROM time) as year,
EXTRACT(HOUR FROM time) AS hour,
EXTRACT(MINUTE FROM time) as minute,
EXTRACT(SECOND from time) as second
FROM
table
New to SQL, but trying to learn/do a job for a friend. I have a query set up that returns the number of bookings for the day. Example snippet:
...
WHERE be.event IN ('instant_approve', 'approve') AND TO_CHAR(be.created_at, 'yyyy-mm-dd') BETWEEN '2017-06-26' AND '2017-06-26';
Now, this query is set up for just today. How can I set this up so that tomorrow the query is executed for '2017-06-27' and so on? Is this possible?
Built-in function now() gives you a timestamp of the beginning of your transaction (CURRENT_TIMESTAMP pseudo-constant is its "alias", a part of SQL standard, but I prefer using the function).
Another function, date_trunc() gives you a "truncated" timestamp and you can choose, how to truncate it. E.g., date_trunc('day', now()) will give you the date/time of beginning of the current day.
Also, you can add or subtract intervals easily, so here is an example that gives you the beginning of the current and the next days:
select
date_trunc('day', now()) cur_day_start,
date_trunc('day', now() + interval '1 day') as next_day_start
;
Also, I would not use to_char() or anything else on top of created_at column -- this will not allow Postgres planner use index on top of this field. If you do want to use to_char(), then consider adding a functional index over to_char(created_at, 'yyyy-mm-dd').
Here is how I would retrieve records generated at July 26, 2017:
where
created_at between '2017-06-26' and '2017-06-27'
(implicit type casting from text to timestamps here)
This is equivalent to
where
created_at >= '2017-06-26'
and created_at <= '2017-06-27'
-- so all timestamps generated for July 26, 2017 will match. And for such query Postgres will use a regular index created for created_at column (if any).
"Dynamic" version:
where
created_at between
date_trunc('day', now())
and date_trunc('day', now()) + interval '1 day'
Use current_date built-in function in the between condition and it will work only for today's bookings.
.........
WHERE be.event IN ('instant_approve', 'approve') AND TO_CHAR(be.created_at, 'yyyy-mm-dd') =current_date;
For some reason I'm kind of lost on how to archive:
SELECT * FROM table WHERE timestamp IS WITHIN THIS MONTH;
I've looked at https://www.postgresql.org/docs/9.4/static/functions-datetime.html, but are only able to select X days backwards.
I'm running PostgreSQL 9.4
... WHERE date_trunc('month', timestamp)
= date_trunc('month', current_timestamp);
Alternatively:
... WHERE timestamp >= date_trunc('month', current_timestamp)
AND timestamp < date_trunc('month', current_timestamp) + INTERVAL '1 month';
The second version can use an index on timestamp, the first would need one on the expression date_trunc('month', timestamp).
Why don't you just filter the month with between ?
Pass the start of this month as variable1, and the end of this month as variable2...
SELECT * FROM table WHERE
timestamp >= __month_start AND timestamp < __next_month_start
e.g.
SELECT * FROM table
WHERE
(
timestamp >= '20170701'::timestamp
AND
timestamp < '20170801'::timestamp
)
Unlike using functions in the where-clause, this maintains sargability.
What Laurenz Albe suggested will work, however you're going to have a performance penalty because you'll lose cardinality on that field, you either have to index expression you're going to query (Apparently PostgreSQL allows to do that: https://www.postgresql.org/docs/current/static/indexes-expressional.html) or create a separate column to store yyyy-mm values and query it.
Now I've found a lot of similar SO questions including an old one of mine, but what I'm trying to do is get any record older than 30 days but my table field is unix_timestamp. All other examples seem to use DateTime fields or something. Tried some and couldn't get them to work.
This definitely doesn't work below. Also I don't want a date between a between date, I want all records after 30 days from a unix timestamp stored in the database.
I'm trying to prune inactive users.
simple examples.. doesn't work.
SELECT * from profiles WHERE last_login < UNIX_TIMESTAMP(NOW(), INTERVAL 30 DAY)
And tried this
SELECT * from profiles WHERE UNIX_TIMESTAMP(last_login - INTERVAL 30 DAY)
Not too strong at complex date queries. Any help is appreciate.
Try something like:
SELECT * from profiles WHERE to_timestamp(last_login) < NOW() - INTERVAL '30 days'
Quote from the manual:
A single-argument to_timestamp function is also available; it accepts a double precision argument and converts from Unix epoch (seconds since 1970-01-01 00:00:00+00) to timestamp with time zone. (Integer Unix epochs are implicitly cast to double precision.)
Unless I've missed something, this should be pretty easy:
SELECT * FROM profiles WHERE last_login < NOW() - INTERVAL '30 days';
How about
SELECT * from profiles WHERE last_login < VALUEOFUNIXTIME30DAYSAGO
or
SELECT * from profiles WHERE last_login < (extract(epoch from now())-2592000)
Have a look at this post:
https://dba.stackexchange.com/questions/2796/how-do-i-get-the-current-unix-timestamp-from-postgresql
and this
http://www.epochconverter.com/
How do I select the date as a readable string from epoch time in milliseconds?
Some like: SELECT *, to_date(time_in_milli_sec) FROM mytable
Per PostgreSQL docs:
SELECT *, to_timestamp(time_in_milli_sec / 1000) FROM mytable
SELECT timestamp 'epoch' + time_in_millisec * interval '1 ms'
FROM mytable;
See the manual here.
For milliseconds
SELECT timestamp 'epoch' + proyecto.fecha_inicio * interval '1 ms'
from proyecto.proyecto
where proyecto.fecha_inicio is not null
For seconds
SELECT TIMESTAMP WITH TIME ZONE 'epoch' + 982384720 * INTERVAL '1 second';
In the manual : http://www.postgresql.org/docs/current/interactive/functions-datetime.html.
Line: .. "Here is how you can convert an epoch value back to a time stamp"..
Original question was related to Date data type, but all the answers so far relate to Timestamp data type.
One way to convert milliseconds to Date would be:
SELECT DATE(any_time_field_containing_milliseconds/ 1000) FROM mytable;
This seems to use the timezone defined for database