device_id
device_created_at
10e7983e-6a7b-443f-b0fe-d5e6485a502c
2022-08-10 20:55:16.695
i have a table where my date/time is of form: 2022-08-10 20:55:16.695 This is a timestampped object. I tried the following query but didn't return any rows:
select * from device where to_char(device_created_at,'YYYY-MM-DD HH24:MI:SS.FFF') = '2022-08-10 20:55:16.695'
The type of device_created_at is "timestamp without time zone"
How do i query based on timestamp in postgressql?
Try comparing timestamp values in place of strings:
SELECT *
FROM device
WHERE device_created_at = CAST('2022-08-10 20:55:16.695' AS TIMESTAMP)
Check the demo here.
Related
I want to find the latest value of a column for particular time duration(1 minute in my case) from Kusto table.
I have timeseries data in PostgreSQL table and I am using last() function (https://docs.timescale.com/api/latest/hyperfunctions/last/)to find the latest value of scaled_value for 1 minute time bucket of PostgreSQL and I want to use same function in Kusto Table to get the latest value of scaled_value . What will be correct function to use in Kusto corresponding to last() function in Postgresql
Code I am using in PostgreSQL :
SELECT CAST(EXTRACT(EPOCH FROM time_bucket('1 minutes', timestamp) AT TIME ZONE 'UTC') * 1000 AS BIGINT) as timestamp_epoch,
vessel_telemetry.timeSeries,
last(vessel_telemetry.scaled_value, vessel_telemetry.timestamp) as scaled_value,
FROM shipping.vessel_telemetry
WHERE vessel_telemetry.ingested_timestamp >= '2022-07-20T10:10:58.71Z' AND vessel_telemetry.ingested_timestamp < '2022-07-20T10:15:33.703985Z'
GROUP BY time_bucket('1 minutes', vessel_telemetry.timestamp), vessel_telemetry.vessel_timeSeries
Corresponding code I am using in ADX
VesselTelemetry_DS
| where ingested_timestamp >= datetime(2022-07-20T10:10:58.71Z) and ingested_timestamp < datetime(2022-07-20T10:15:33.703985Z)
| summarize max_scaled_value = max(scaled_value) by bin(timestamp, 1m), timeSeries
| project timestamp_epoch =(datetime_diff('second', timestamp, datetime(1970-01-01)))*1000, timeSeries, max_scaled_value
The data that i am getting using PostgreSQL is not matching with the data I am getting from ADX Query. I think the functionality of last() function of Postgre is different from max() function of ADX. Is there any function in ADX that we can use to perform same as last() of PSQL
arg_max()
arg_max (ExprToMaximize, * | ExprToReturn [, ...])
Please note the order of the parameters, which is opposite to Timescale's last() -
First the expression to maximize, in your case timestamp and then the expression(s) to return, in your case scaled_value
I am trying to write a SQL query where the results would show the first value (ID) per user per day for the last year.
I tried using the query below and am able to get results for one day but when I try to change the time range to > 2021-06-01, it does not give me the results I expect.
select * from table
where value in
(
SELECT min(value)
FROM table
WHERE valueid = x
group by user
) and Time = '2022-05-30' and value is not null
I have a big table in a postgres db with location of units. Now I need to retrieve a location for every 60 seconds.
In Mysql, this is a piece of cake: select * from location_table where unit_id = '123' GROUP BY round(timestamp / 60)
But in postgres this seems to be a very hard problem. I also have the timestamps in dateformat rather than in epoch format.
Here is an example of how the table looks
CREATE TABLE location_table (
unit_id int,
"timestamp" timestamp(3) without time zone NOT NULL,
lat double precision,
lng double precision
);
Use date_trunc() to make sets per minute:
SELECT * -- most likely not what you want
FROM location_table
WHERE unit_id = 123 -- numbers don't need quotes '
GROUP BY date_trunc('minute', 'timestamp');
The * is of course wrong, but I don't know what you want to know about the GROUP so I can't come up with something better.
Edit:
When you need a random result from your table, DISTINCT ON () could do the job:
SELECT DISTINCT ON(date_trunc('minute', timestamp))
* -- your columns
FROM location_table;
There are other (standard SQL) solutions as well, like using row_number().
select complaintno from complaintprocess where endtime='';
It Is Not Working
In complaintprocess table endtime datatype is timestamp without time zone.
Here I want to get one of the column in complaintprocess where endtime is empty.
You could not store '' as timestamp. I suspect that by blank you mean NULL value.
SELECT CAST('' AS timestamp);
-- ERROR: invalid input syntax for type timestamp: ""
To filter them you could use:
SELECT complaintno
FROM complaintprocess
WHERE endtime IS NULL;
I am trying to run a simple query which gets me data based on timestamp, as follows:
SELECT *
FROM <table_name>
WHERE id = 1
AND usagetime = timestamp('2012-09-03 08:03:06')
WITH UR;
This does not seem to return a record to me, whereas this record is present in the database for id = 1.
What am I doing wrong here?
The datatype of the column usagetime is correct, set to timestamp.
#bhamby is correct. By leaving the microseconds off of your timestamp value, your query would only match on a usagetime of 2012-09-03 08:03:06.000000
If you don't have the complete timestamp value captured from a previous query, you can specify a ranged predicate that will match on any microsecond value for that time:
...WHERE id = 1 AND usagetime BETWEEN '2012-09-03 08:03:06' AND '2012-09-03 08:03:07'
or
...WHERE id = 1 AND usagetime >= '2012-09-03 08:03:06'
AND usagetime < '2012-09-03 08:03:07'
You might want to use TRUNC function on your column when comparing with string format, so it compares only till seconds, not milliseconds.
SELECT * FROM <table_name> WHERE id = 1
AND TRUNC(usagetime, 'SS') = '2012-09-03 08:03:06';
If you wanted to truncate upto minutes, hours, etc. that is also possible, just use appropriate notation instead of 'SS':
hour ('HH'), minute('MI'), year('YEAR' or 'YYYY'), month('MONTH' or 'MM'), Day ('DD')