Postgres timestamp to date - postgresql

I am building a map in CartoDB which uses Postgres. I'm simply trying to display my dates as: 10-16-2014 but, haven't been able to because Postgres includes an unneeded timestamp in every date column.
Should I alter the column to remove the timestamp or, is it simply a matter of a (correct) SELECT query? I can SELECT records from a date range no problem with:
SELECT * FROM mytable
WHERE myTableDate >= '2014-01-01' AND myTableDate < '2014-12-31'
However, my dates appear in my CartoDB maps as: 2014-10-16T00:00:00Z and I'm just trying to get the popups on my maps to read: 10-16-2014.
Any help would be appreciated - Thank you!

You are confusing storage with display.
Store a timestamp or date, depending on whethether you need time or not.
If you want formatted output, ask the database for formatted output with to_char, e.g.
SELECT col1, col2, to_char(col3, 'DD-MM-YY'), ... FROM ...;
See the PostgreSQL manual.
There is no way to set a user-specified date output format. Dates are always output in ISO format. If PostgreSQL let you specify other formats without changing the SQL query text it'd really confuse client drivers and applications that expect the date format the protocol specifies and get something entirely different.

You have two basic options.
1 Change the column from a timestamp to a date column.
2 Cast to date in your SQL query (i.e. mytimestamp::date works).
In general if this is a presentation issue, I don't usually think that is a good reason to muck around with the database structure. That's better handled by client-side processing or casting in an SQL query. On the other hand if the issue is a semantic one, then you may want to revisit your database structure.

Related

How Can I compare table column by convert it first in postgresql + typeorm

I am beginner in Backend technology and I am developing one query in Typeorm QueryBuilder + PostgreSQL.
My query is look like this :
But I can't convert my timestamp into following format. Can anyone who has expertise in it, please help me to select all records with timestamp in specific format.
I am suffering this things from last two days but still not find any solution. Actually I want to compare this date format in having clause. so I want to first select that date format then I can use that same method to compare column with current date and previous dates.

Date format in where clause match date format from table

I'm using previously written scripts that have the date format in the WHERE clause as 'DD-MMM-YY', however, in the table it is formatted as 'DD-MMM-YY HH.MM.SS.000000000 AM/PM. Does it matter that these formats do not match up? After comparing results it doesn't seem like any data is missing using non-matching formats. Wasn't sure if efficiency would be different if they matched or didn't match? Just let me know your thoughts and opinions. Thanks all!
Your where clause is fine. The table formatting is just a representation of the date. You can change this if it helps you view the results more easily (see link below), but it will make no difference to the efficiency of the query.
How can I set a custom date time format in Oracle SQL Developer?

Is ISO8601 the best date-format for PostgreSQL jsonb when i want to filter by the date?

I'm new to PostgreSQL and I have the following question:
I have a table with just an id-column and a data-column, which uses the jsonb-type. Inside the jsonb-object I have a datetime field. I read in various posts, that I should use the ISO-8601 dateformat to store in the DB.
I want to filter my table by date like this:
SELECT * FROM table WHERE data->'date' > '2016-01-01T00:00'
Is this really the best date-format for this purpose?
Thanks in advance :)
IMHO Your query should produce
ERROR: operator does not exist: jsonb > timestamp with time zone
If I get it right. In case you change -> to ->> it should get a text value instead of jsonb field (which is also not comparable to timestamp).
It should be smth like
SELECT * FROM table WHERE (data->>'date')::timestamptz > '2016-01-01T00:00' to work
The big advantage of that format is that string order corresponds to date order, so a comparison like the one you quote in your question would actually work as intended.
A second advantage is that a timestamp in that format can easily be converted to a PostgreSQL timestamp with time zone value, because the type input function understands this format.
I hope you are not dealing with dates “before Christ”, because it wouldn't work so easily with those.

IBM i (AS400/ISeries) - Adding days to date field in WRKQRY

I have a decimal date field (TDDATR) that is in the YYYYMMDD format.
I would like to create a field that is TDDATR + 30 days but I am unable to.
Using 'Define Results Field' I have tried a few things;
Simply doing this;
TDDATR + 30 DAYS
But it returned this error: Labeled duration not used correctly.
I tried using the DIGITS and SUBSTR commands to create a field in the DDMMYYYY format and then +30 days but got the same error.
Same as above but in the DD/MM/YYYY format - same error.
Using DATE(TDDATR) but all I see is +'s in the field.
Using DATE( ) on the fields created in step 2 and 3 - still get +'s
I've ran out of ideas - any help would be greatly appreciated.
Query/400 lacks a lot of the features that an SQL based interface has.
I'd urge you to consider switching to Query Manager (STRQM) which is a fully SQL based product. You can even convert Query/400 queries to Query Manager queries with the RTVQMQRY command by having the ALWQRYDFN parm set to *YES.
The other option that IBM is pushing is Web Query. Again, fully SQL based and you can convert Query/400 queries into it.
Having said that, the problem is that FLD + 30 DAYS only works when FLD is a DATE data type. Query/400 includes a DATE() function to convert non-date types into date. But it's very limited in that it only works with character fields formatted according to your job defaults. Assuming you're in the US, it'd only work with a character value of '07/01/15'.
You could do a lot of manipulation in Query/400 and end up with a result field that meets DATE()'s requirements. But a better solution would be to create an SQL view over your table and have your numeric date converted into a date data type in the view.
You can find code examples that show how to convert a numeric YYYYMMDD to a actual date data type in the view. However, I'd recommend create a user defined function (UDF) that will do the conversion for you. That will make it much easier to use in the view and to reuse in other places.
If you'd like, there's an open source package called iDate, that includes all the code required for convert to/from date data types.
Download that, install/compile it and your SQL view becomes
select ... idate(TDDATR,'*CCYMD') as TD_DATE
from myfile
The use of days is as follow
Field Expression
CURDATE_30 days(current(date)) + 30
The solution to your problem is: given the field A dec(8,0)
Field Expression
YYYYMMDD_ date(substr(digits(a),5,2)||'/'||
substr(digits(a),7,2)||'/'||
substr(digits(a),3,2))
NEXT_MONTH DAYS(YYYYMMDD_) + 30
Remember to check the date format in your job description. In the example the format is MDY or MM/DD/YY.
More info here
Based on the information here, I created the below 2 fields;
TDDIGI DIGITS(TDDATR)
TDDAT1 SUBSTR(TDDIGI,7,2)||'/'||
SUBSTR(TDDIGI,5,2)||'/'||
SUBSTR(TDDIGI,3,2)
From here I was able to create a date field;
TDDAT2 DATE(TDDAT1)
Which allowed me to perform the necessary calculations.
The format of TDDAT1 is based on your job description which can be found by;
WRKJOB
Option 2
Page down
Date format..: X
Mine was *DMY, so TDDAT1 was formatted based on this.

convert string date(yyyy/mm/dd) to date format in db2

I am saving the date as varchar in db2 with yyyy/mm/dd format i need to convert it to date datetype in the query how to achieve this?
I tried
select DATE(CRDTR2) from ASAODLIB.SSLR204 where CRDTR2 BETWEEN
'2015/03/01' AND '2015/03/31';
query and got the below error
The syntax of the string representation of a datetime value is
incorrect.. SQLCODE=-180, SQLSTATE=22007, DRIVER=3.68.61
can someone help me.
If your DB2 version is new enough, use to_date: select DATE(TO_DATE(CRDTR2, 'YYYY/MM/DD')) from ...
...because it doesn't recognize that format. I'd turn it into *ISO first, via REPLACE:
SELECT DATE(REPLACE(CRDTR2, '/', '-'))
FROM ASAODLIB.SSLR204
WHERE CRDTR2 BETWEEN '2015/03/01' AND '2015/03/31'
Incidentally, there's a couple other things here.
You should be storing dates as an actual date type, which would make this a non-issue.
You shouldn't use BETWEEN, in preference for an exclusive upper-bound (< - the blog talks about SQL Server, but the problem is really due to representation. That, and most versions of DB2 allow you to specify fractional seconds in timestamps...).