I am using Perl's DBD::ODBC to connect to an Oracle database. However, an issue arises when I try to execute a select query using a date in the where clause. It seems this issue occurs because of the database's date format being DD-MON-RR (see DBD::ODBC::FAQ). Since I cannot change the database's settings, can anyone suggest a workaround?
The database's default date format only matters if you depend on it, which you should not in general. You can:
1) Specify the format of the date in your query:
select *
from news
where news_date = to_date ('01-DEC-2009','DD-MON-RRRR');
2) Use the ANSI standard for date literals:
select *
from news
where news_date = DATE '2009-12-01';
One option is to use the TO_DATE() function (or the ANSI 'DATE' keyword) to convert the format in every query:
WHERE date_field > TO_DATE('2009-11-01', 'YYYY-MM-DD');
-- or
WHERE date_field > DATE '2009-11-01'
If you have to do this a lot, a better option would be to set the format for the session:
$dbh->do("ALTER SESSION SET NLS_DATE_FORMAT='YYYY-MM-DD HH24:MI:SS'");
$dbh->do("ALTER SESSION SET NLS_TIMESTAMP_FORMAT='YYYY-MM-DD HH24:MI:SSxFF'");
$dbh->do("ALTER SESSION SET NLS_TIMESTAMP_TZ_FORMAT='YYYY-MM-DD HH24:MI:SSxFF'");
Then:
my $sth = $dbh->prepare(<<EOT);
SELECT date_field
FROM some_table
WHERE date_field > '2009-11-01'
EOT
Don't rely on implicit datatype conversion. You can always specify the date format in the where clause:
WHERE your_column = to_date(:your_parameter, 'yyyy/mm/dd')
Related
Does anyone have any idea how to convert a date formatted "mmm-yy" (varchar) to "dd-mm-yyyy" or only from varchar data type to date data type.
It actually depends on what language or tool you are using, but there is almost certainly a builtin function that will help you do this.
Checkout
MySQL: DATE_FORMAT()
Oracle: SELECT TO_CHAR(SYSDATE, 'DD-MM-YYYY') FROM dual;
SQL Server: SELECT CONVERT(VARCHAR(10), GETDATE(), 120);
Or if you are doing this using a programing language i.e., Python, JavaScript etc. Just use the built in string replace methods to change the date into your desired format.
I getting an XML date/time from an XML file and need to load it in a datatype of just Date, so I have to truncate the time.
I would like to try something like this in order to let Oracle do the truncation:
TO_DATE('2015-11-04 13:45:19.387-05:00','YYYY-MM-DD')
I verify this failed by running this:
SELECT TO_DATE('2015-11-04 13:45:19.387-05:00','YYYY-MM-DD') FROM DUAL
It throws error: ORA-01830: data format picture ends before converting entire string.
I'm trying to minimize change to my C# program that is building the SQL statements. If I need to, I can change my C# code to generate this:
TO_DATE('2015-11-04','YYYY-MM-DD')
Can Oracle handle the truncation or must I do it in my program?
If you're storing your information in a DATE column in Oracle (which accepts date-and-time), then the following should help you see what you need to do:
select to_timestamp_tz('2015-11-04 13:45:19.387-05:00','YYYY-MM-DD hh24:mi:ss.ff3tzh:tzm') tz,
to_date(to_char(to_timestamp_tz('2015-11-04 13:45:19.387-05:00','YYYY-MM-DD hh24:mi:ss.ff3tzh:tzm'), 'dd/mm/yyyy hh24:mi:ss'), 'dd/mm/yyyy hh24:mi:ss') tz_char_date,
cast(to_timestamp_tz('2015-11-04 13:45:19.387-05:00','YYYY-MM-DD hh24:mi:ss.ff3tzh:tzm') as date) tz_cast_date
from dual;
TZ TZ_CHAR_DATE TZ_CAST_DATE
---------------------------------------- ------------------- ---------------------
04/11/2015 13:45:19.387000000 -05:00 04/11/2015 13:45:19 2015-11-04 13:45:19
An alternative is to use substr to shorten the string to get the portion you're interested in:
select to_date(substr('2015-11-04 13:45:19.387-05:00', 1, 19), 'yyyy-mm-dd hh24:mi:ss') substr_date
from dual;
SUBSTR_DATE
---------------------
2015-11-04 13:45:19
You can use the to_timestamp_tz() function to convert the string from XML into a timestamp with timezone value:
SELECT TO_TIMESTAMP_TZ('2015-11-04 13:45:19.387-05:00','YYYY-MM-DD HH24:MI:SS.FFTZH:TZM')
FROM DUAL;
TO_TIMESTAMP_TZ('2015-11-0413:45:19.387-05:00','YYYY-MM-DDHH24:MI:SS.FFTZH:TZM')
--------------------------------------------------------------------------------
04-NOV-15 13.45.19.387000000 -05:00
You can then use the trunc() function to truncate the time portion to midnight; this also converts it implicitly from a timestamp to a date:
SELECT TRUNC(TO_TIMESTAMP_TZ('2015-11-04 13:45:19.387-05:00','YYYY-MM-DD HH24:MI:SS.FFTZH:TZM'))
FROM DUAL;
TRUNC(TO_TIMESTAMP_TZ('2015-11-0413:45:19.387-05:00','YYYY-MM-DDHH24:MI:SS.FFTZH
--------------------------------------------------------------------------------
04-NOV-15
This ignores the actual time zone - essentially assuming the values are in your system timezone (i.e. you are in the same -05:00 region).
You could also use a substring to strip the time and timezone part from the raw string before converting:
SELECT TO_DATE(SUBSTR('2015-11-04 13:45:19.387-05:00', 1, 10), 'YYYY-MM-DD')
FROM DUAL;
TO_DATE(SUBSTR('2015-11-0413:45:19.387-05:00',1,10),'YYYY-MM-DD')
-----------------------------------------------------------------
04-NOV-15
... or performing the substring in C# if you prefer, assuming that is parsing the XML document.
(These are intentionally displaying in a format that is different from the ISO standard so they don't look like the original string value from your XML; they are actual date/timestamp with time zone types, my client is just using my NLS settings.)
You also have the option of using Oracle's built-in XML handling to extract relational data from your document, but that's rather off-topic and might not be appropriate.
I have the following function:
CREATE function SEMANA_ISO (fecha date) returns text as $$
select to_char(fecha, 'mm-dd-yyyy');
$$ LANGUAGE sql;
It works with:
Select SEMANA_ISO ('28/12/2014');
Select SEMANA_ISO ('01/01/2015');
Select SEMANA_ISO ('01/07/2015');
As you may see below
But not with:
Select SEMANA_ISO ('12/31/2014');
It shows:
********** Error **********
ERROR: The value of time / date is out of range "12/31/2014"
SQL state: 22008
Hint: You may need a different configuration of "dateStyle".
Character: 20
Do you have any suggestion without having to change the datestyle so I can enter
Select SEMANA_ISO ('12/31/2014');
And get an output of:
12-31-2014
using just one function to "parse" all dates?
Your function is declared to get a parameter of type date so you also need to pass such a value. '12/31/2014' is a character value, not a date.
When you pass a character literal (aka string) to the function Postgres is forced to do an implicit data type conversion based on the current datestyle - not something you should rely on.
If you want to call the function independently of the datestyle you need to pass a proper date literal, e.g. DATE '2014-12-31'
For more details on specifying date values, please see the manual: http://www.postgresql.org/docs/current/static/datatype-datetime.html#DATATYPE-DATETIME-INPUT
If you want 12/31/2014 accepted as a date set datestyle to iso, dmy;
if you want 31/12/2014 accepted as a date set datestyle to iso, mdy;
you can't have both at the same time, else 4/1/2015 is ambiguos, and must be rejected.
There is to_date() to input date literals with an arbitrary (given) format:
SELECT to_date('12/31/2014', 'MM/DD/YYYY') AS date1
, to_date('31/12/2014', 'DD/MM/YYYY') AS date2;
That's "without changing any datestyle". Obviously, you need to provide a matching format pattern, though.
To output the same in any desired format, use to_char():
SELECT to_char(to_date('12/31/2014', 'MM/DD/YYYY'), 'DD/MM/YYYY') AS date_as_text
Is there any other way to get datetime field from oracle database in 24hour format???like
-> "select getxsddate(col_name) from tab_name" will get you datetime format as "2012-04-04T12:31:00"...I wanted to know if there are any other ways as i`m not satisfied with this format.
select to_char(col_name, 'yyyy-mm-dd hh24:mi:ss') from tab_name
You can read more about to_char function here
Another very simple way is to set, in the database nls parameters, the parameter date_format='DD-MM-YYYY HH24:MI:SS'
In Oracle, I can SELECT sysdate FROM dual to get the current system date/time.
How can I do the same accessing a FileMaker database via the JDBC driver?
Note: "Don't use FileMaker" is unfortunately not an option.
Create an unstored calc field that calls Get ( CurrentHostTimeStamp ) and then include that field as one of your selected fields.
(Make sure you configure the field's options so that FileMaker does not store the calculation results - unless you want the date/time of when the field was added...)
I don't know FileMaker, but maybe the standard (ANSI SQL) expressions CURRENT_DATE or CURRENT_TIMESTAMP work?
So something like
SELECT CURRENT_TIMESTAMP
FROM whatever
Edit:
Another thing to try could be the standard JDBC escape function:
SELECT {fn CURTIME()}
FROM whatever