I have created a Timestamp field in a FileMaker Pro 11 database and set the field (under File>Manage>Database) to auto-enter a Modification Timestamp (Date and Time) into the field.
I want to override this auto-enter value during data entry by typing a timestamp myself, but upon commit, FileMaker replaces what I type with an auto-enter timestamp. This is the same for updating the field as well.
Is this possible to do somehow?
Offhand I can't think of a way to do this with only one field. A three-field solution would work fairly easily, however.
Create 3 fields:
Modification Timestamp (set to auto-enter Modification Timestamp)
Override Timestamp (set to type: Timestamp)
Display Timestamp (set to the calculation below:)
Display Timestamp:
// If Override Timestamp is Empty, show Modification Timestamp.
// Otherwise show Override Timestamp.
If ( IsEmpty ( Override Timestamp ) ;
Modification Timestamp ;
Override Timestamp )
Then you place Override Timestamp underneath Display Timestamp. Set Override Timestamp to be enterable only in Browse mode. Set Display Timestamp to be enterable only in Find mode.
From the UI perspective the two fields will seem to be the same field, but you'll get the desired result.
Related
I am using below condition to truncate date in postgres
to_date(to_char(trunc(appointment_date),'YYYYMMDD')||appointment_end_time,''YYYYMMDDHH24:MI:SS')AS tq
How I can use this in postgres ?
Strange data typing, sometimes requires strange, looking at least, queries. Try (see fiddle)
date_trunc('day',appointment_date)
+ substr(appoinment_end,12)::interval
As your to_char() call uses the format 'HH24:MI:SS' for the "time" column, you can cast that column directly to a time value, e.g. using the :: operator: appointment_end_time::time.
To build a new timestamp from the date part of the appointment_date and the time value, just add them:
appointment_date::date + appointment_end_time::time
So first the timestamp is converted to a date (that does not have a time), and then the time value is added to that, which yields a timestamp.
Note that to_date() returns a date so your code would remove the just added time part again. You would need to use to_timestamp() if you really want a timestamp as the result.
To answer the question's title "how to truncate date in Postgres?" (which in reality refers to a timestamp not a date): you can either cast it to a date (see above) or you can use date_trunc() (not trunc()) with a unit to which it should be truncated. However, date_trunc returns a timestamp not a date value, so you couldn't add a time to the result.
What is the best way to store a timestamp value in Postgresql in a specific format.
For example I would like to store a TIMESTAMP '2020-07-09 17:29:30.873513Z' down to the minute and ignore seconds value.
I can drop the seconds by using date_trunc('minute', TIMESTAMP '2020-07-09 17:29:30.873513Z') Is there anyway for me to specify this format in the column itself when I create a table?
Don't store formatted timestamps in the database, use timestamp with time zone or timestamp without time zone. You would lose powerful datetime arithmetic, value checking and waste storage space.
To have the values truncated to minute precision, use a BEFORE INSERT trigger that uses date_trunc on the value.
If you want to ascertain that only such values are stored, add a check constraint.
I would like to recommend not to drop seconds or anything from the stored data. Because it will create issues while you process the data later. And if you have to eliminate anything, you may eliminate it while retrieving the data.
Use the following code while creation of table
col_name timestamp without time zone DEFAULT timezone('gmt'::text, now())
This will give you a result as shown in the following image:
Good Luck.
We are having some columns in database with data type 'timestamp with time zone'. We are populating with now() function as default value. Sometimes it is getting populated with dates from 2017/18. What might be the issue?
If you are using now() as default value, the likely cause of your problem is that these dates are inserted explicitly. Remember that the default value is only used if no value is supplied for the column.
There are other, much less likely explanations like database transactions that have been open for a year, but I don't believe that.
If you always want to override the value, use a BEFORE trigger.
I already have a date time column which is updated every time I ingest new data and it works, but I would like to do the same for a new column but just with the date, not the time. Please see the picture attached. What should I write in the Default option? Table column definitions
You could set the default value to CURRENT_DATE ON UPDATE CURRENT_DATE in your EventDate field.
But wouldn't it be better to extract date from the already existing EventDateTime field with DATE_FORMAT(EventDateTime, '%Y-%m-%d') or DATE(EventDateTime) functions?
I'm in a tricky situation. A client's database timezone was configured for America/Chicago instead of UTC.
From the app, we ask customers to enter useful dates, and sadly those dates are stored 'as-is', so if they entered '2001-01-01 00:00:00' in the text input, that same value will be stored in the DB, and we are ignoring the customer's timezone. We save that info separately.
The table column is of type TIMEZONETZ. So Postgresql will add the America/Chicago timezone offset at the end: Eg '2001-01-01 00:00:00-02'.
Naturally, most of the customers are not in Chicago.
The difficult part, is that, even knowing the customer's timezone, it's really hard to run calculations on the DB given that the datetime was not correctly pre-processed before storing it into the DB.
My attempted solution, is finding a way to extract the datetime string from the column value, and re-convert it to a date with the right timezone. Eg (pseudo-code):
// This is psuedo code
SELECT DATETIME((SELECT date_string(mycolumn) FROM mytable),
TIMEZONE('America/Managua'));
Which would be equivalent in PHP:
$customerInput = '2016-01-01 00:00:00';
$format = 'Y-m-d H:i:s';
$wrongDateStoredInDb = DateTime::createFromFormat($format, $customerInput, new DateTimezone('America/Chicago'));
// In order to fix that date, I'd extract the dateString and create a new DateTime but passing the correct timezone info.
$customerTimezone = new Timezone('America/Bogota');
$customerInput = $wrongDateStoredInDb->format($format); // Assuming we didn't have it already.
$actualDateTime = DateTime::createFromFormat($format, $customerInput, $customerTimezone);
With that kind of information, I'd be able to run calculations on date ranges, with the correct values, eg:
// Pseudo-code
SELECT * FROM myTable WHERE fix_date_time(columnWithInvalidDate, `correctTimezone`)::timestamp > `sometimestamp`;
I've read the Postgresql docs, and I've tried everything I could, but nothing seems to work.
Any suggestion is more than welcomed!
So you say that you have a timestamptz column. That is not stored as a string, but as an "instant" in microseconds since the epoch. But when you do an INSERT and give a string, Postgres converts your string into a time value automatically, before storing it. It's been assuming the strings you give it are in Chicago time, since that's the default timezone.
Now you want to reinterpret those times as being in the user's time zone instead. To do that, you can put them back into strings (in Chicago time), and then parse them again but with a different time zone.
Suppose you have data like this:
CREATE TABLE t (id int primary key, ts timestamptz, tz text);
SET TIMEZONE='America/Chicago';
INSERT INTO t
VALUES
(1, '2015-01-01 12:00:00', 'America/Managua'),
(2, '2015-01-01 12:00:00', 'America/Los_Angeles')
;
Then this will give you new times that are what the user really meant:
SET TIMEZONE='America/Chicago';
SELECT ts::text::timestamp AT TIME ZONE tz FROM t;
To break it down: ts::text stringifies the value into Chicago time, then we re-parse it, but into a bare timestamp with no timezone information yet. Then we attach a time zone---not Chicago time, but the user's own timezone.
From here you should be able to handle fixing the bad rows (and not the new ones, if you've already changed the server's default timezone).
One caveat is that if a user entered a time and then changed their timezone, there is no way to recover that, so this will interpret that old time incorrectly.