I have a date with the column name "date" in my table "productions" stored as integer with Unix format ( example: 1548263300000). And I want to retrieve only the year. When I do:
SELECT strftime('%Y ',date) as year
FROM productions
it returns null.
When I change the type to TEXT into my table and I store the date in string format ( example 2020-05-01 ), the same sql returns me "2020" which is correct and what I was looking for.
Why strftime() doesn't work with integers since the SQLite documentation say you can work with TEXT,INTEGER and REAL for dates? How to use date functions with integers?
extra information:
In this tutorial, they also use strftime with integers and it seems to work for them, so I understand from that, that the functions are available no matter what type you use ( text,int,real): link
when I use:
SELECT strftime('%Y',DATETIME(ROUND(date/ 1000), 'unixepoch'))
FROM productions;
it works fine, but I don't understand why I have to do all this when I use integers but when I use text, it works directly.
You can use strftime() but you have to add the 'unixepoch' modifier:
strftime('%Y', date / 1000, 'unixepoch')
so your date / 1000 is recognized as the number of seconds since 1970-01-01.
From Date And Time Functions:
The "unixepoch" modifier (11) only works if it immediately follows a
timestring in the DDDDDDDDDD format. This modifier causes the
DDDDDDDDDD to be interpreted not as a Julian day number as it normally
would be, but as Unix Time - the number of seconds since 1970.
Related
I need to filter by month in Sqlite, but the STRFTIME function returns Null.
The dates seem to be in a standard format.
SELECT arrival_date a,
departure_date d,
strftime('%m', arrival_date) m
FROM table
Returns (for example):
13/02/2015, 15/02/2015, Null
Is there any way to work around this?
strftime(), and all other sqlite date and time functions, will return null if given an argument in a format that they don't understand. DD/MM/YYYY formatted dates like 13/02/2015 are not an understood format. The complete list is in the documentation, but if storing just a date as a string, YYYY-MM-DD is what you need to use.
The strftime function for SQLite is intended to be used to parse a text date, perform some manipulation (e.g. adding some days), and then returning an output date string. If you just want to extract the numerical month component, then use substr:
SELECT
arrival_date a,
departure_date d,
substr(arrival_date, 4, 2) m
FROM table;
I have a Firebird database that saves the datetime field as a DOUBLE. I have created a ColdFusion datasource connection, so I can query the data remotely. While the rest of the data is being returned correctly, the datetime field is unreadable. I have tried using CAST and CONVERT to no avail. How can I convert this to a timestamp?
An example of the data stored is: 43016.988360
You can't just convert a DOUBLE PRECISION to a TIMESTAMP, not without explicitly defining how you want it mapped and writing that conversion yourself (or hoping there is an existing third-party UDF that does this for you).
A TIMESTAMP in Firebird is a date + time represented as an 8 byte value, where the date range is from January 1, 1 a.d. to December 31, 9999 a.d. and the time range is 00:00 to 23:59.9999 (so, 100 microsecond precision).
A DOUBLE PRECISION is - usually - the wrong type for storing date and time information, and as you haven't provided how that double value should be interpreted, we can't help you other than saying: there is no default method in Firebird to do this.
Based on the comments below, it looks like the value is a ColdFusion date value stored as double precision with the number of days since December 30th 1899, see also why is ColdFusion's Epoch Time Dec 30, 1899?. If this is really the case, then you can use the following for conversion to a TIMESTAMP:
select timestamp'1899-12-30 00:00' + 43016.988360 from rdb$database
Which will yield the value 2017-10-08 23:43:14.304. Using the value 43182.4931754 from the comments will yield 2018-03-23 11:50:10.354. That is a millisecond off from your expectation, but that might be a rounding/presentation issue, eg I get the exact expected date if I use 43182.49317539 instead.
I would strongly suggest you carefully test this with known values.
I have Oracle database columns with the number format YYYYMMDD. I have not been successful in using this format with datediff to get the difference between two dates. The documentation I've read online uses a different format:
DATEDIFF(day,'2008-06-05','2008-08-05')
What's the best way for me to get number of days between two dates given the format available to me in Oracle? Answers not involving datediff are acceptable as long as it gets the number of days between two dates with the format YYYYMMDD.
Simple subtraction in Oracle:
SELECT TO_DATE('20080805','YYYYMMDD') - TO_DATE('20080605','YYYYMMDD')
FROM DUAL;
Oracle doesn't have a DATEDIFF() function. Instead, you can use simple arithmetic with Oracle dates, where subtracting one date from another gives the number of days, and where you can add an subtract days from a given date. (You can also subtract fractions of days, but that might be outside the scope of this answer.)
To convert your NUMBER dates of the format YYYYMMDD to actual dates, just use the TO_DATE() function (I am pretty sure that Oracle will implicitly convert the NUMBER value to a VARCHAR2 before converting to a date; if not, use TO_CHAR() to do that explicitly).
TO_DATE(20150301, 'YYYYMMDD')
To get the difference between two dates, you can do the following:
SELECT TO_DATE(my_number_date1, 'YYYYMMDD') - TO_DATE(my_number_date2, 'YYYYMMDD')
FROM my_table;
Incidentally, if you want to get intervals instead of days, convert to timestamp (using TO_TIMESTAMP()) instead of converting to date.
When ececute the following SQL syntax in Oracle, always not success, please help.
40284.3878935185 represents '2010-04-16 09:18:34', with microsecond.
an epoch date of 01 January 1900 (like Excel).
create table temp1 (date1 number2(5,10));
insert into temp1(date1) values('40284.3878935185');
select to_date(date1, 'yyyy-mm-dd hh24:mi:ssxff') from temp1
Error report: SQL Error: ORA-01861: literal does not match format
string
01861. 00000 - "literal does not match format string"
*Cause: Literals in the input must be the same length as literals in
the format string (with the exception of leading whitespace). If the
"FX" modifier has been toggled on, the literal must match exactly,
with no extra whitespace.
*Action: Correct the format string to match the literal.
Thanks to Mark Bannister
Now the SQL syntax is:
select to_char(to_date('1899-12-30','yyyy-mm-dd') +
date1,'yyyy-mm-dd hh24:mi:ss') from temp1
but can't fetch the date format like 'yyyy-mm-dd hh24:mi:ss.ff'. Continue look for help.
Using an epoch date of 30 December 1899, try:
select to_date('1899-12-30','yyyy-mm-dd') + date1
Simple date addition doesn't work with timestamps, at least if you need to preserve the fractional seconds. When you do to_timestamp('1899-12-30','yyyy-mm-dd')+ date1 (in a comment on Mark's answer) the TIMESTAMP is implicitly converted to a DATE before the addition, to the overall answer is a DATE, and so doesn't have any fractional seconds; then you use to_char(..., '... .FF') it complains with ORA-01821.
You need to convert the number of days held by your date1 column into an interval. Fortunately Oracle provides a function to do exactly that, NUMTODSINTERVAL:
select to_timestamp('1899-12-30','YYYY-MM-DD')
+ numtodsinterval(date1, 'DAY') from temp3;
16-APR-10 09.18.33.999998400
You can then display that in your desired format, e.g. (using a CTE to provide your date1 value):
with temp3 as ( select 40284.3878935185 as date1 from dual)
select to_char(to_timestamp('1899-12-30','YYYY-MM-DD')
+ numtodsinterval(date1, 'DAY'), 'YYYY-MM-DD HH24:MI:SSXFF') from temp3;
2010-04-16 09:18:33.999998400
Or to restrict to thousandths of a second:
with temp3 as ( select 40284.3878935185 as date1 from dual)
select to_char(to_timestamp('1899-12-30','YYYY-MM-DD')+
+ numtodsinterval(date1, 'DAY'), 'YYYY-MM-DD HH24:MI:SS.FF3') from temp3;
2010-04-16 09:18:33.999
An epoch of 1899-12-30 sounds odd though, and doesn't correspond to Excel as you stated. It seems more likely that your expected result is wrong and it should be 2010-04-18, so I'd check your assumptions. Andrew also makes some good points, and you should be storing your value in the table in a TIMESTAMP column. If you receive data like this though, you still need something along these lines to convert it for storage at some point.
Don't know the epoch date exactly, but try something like:
select to_date('19700101','YYYYMMDD')+ :secs_since_epoch/86400 from dual;
Or, cast to timestamp like:
select cast(to_date('19700101', 'YYYYMMDD') + :secs_since_epoch/86400 as timestamp with local time zone) from dual;
I hope this doesn't come across too harshly, but you've got to totally rethink your approach here.
You're not keeping data types straight at all. Each line of your example misuses a data type.
TEMP1.DATE1 is not a date or a varchar2, but a NUMBER
you insert not the number 40284.3878935185, but the STRING >> '40284.3878935185' <<
your SELECT TO_DATE(...) uses the NUMBER Temp1.Date1 value, but treats it as a VARCHAR2 using the format block
I'm about 95% certain that you think Oracle transfers this data using simple block data copies. "Since each Oracle date is stored as a number anyway, why not just insert that number into the table?" Well, because when you're defining a column as a NUMBER you're telling Oracle "this is not a date." Oracle therefore does not manage it as a date.
Each of these type conversions is calculated by Oracle based on your current session variables. If you were in France, where the '.' is a thousands separator rather than a radix, the INSERT would completely fail.
All of these conversions with strings are modified by the locale in which Oracle thinks your running. Check dictionary view V$NLS_PARAMETERS.
This gets worse with date/time values. Date/time values can go all over the map - mostly because of time zone. What time zone is your database server in? What time zone does it think you're running from? And if that doesn't spin your head quite enough, check out what happens if you change Oracle's default calendar from Gregorian to Thai Buddha.
I strongly suggest you get rid of the numbers ENTIRELY.
To create date or date time values, use strings with completely invariant and unambiguous formats. Then assign, compare and calculate date values exclusively, e.g.:
GOODFMT constant VARCHAR2 = 'YYYY-MM-DD HH24:MI:SS.FFF ZZZ'
Good_Time DATE = TO_DATE ('2012-02-17 08:07:55.000 EST', GOODFMT);
I'm sure this is quite simple, but I've been stuck on it for some time. How can I convert a varchar field (YYYYMM) to a date (MM/01/YY) in SQL?
Thanks.
Edit: I'm using Open Office Base (HSQL), not MySQL; sorry for the confusion.
Try the str_to_date and date_format functions. Something like:
select date_format( str_to_date( my_column, '%Y%c' ), '%c/01/%y' ) from my_table
try :
SELECT STR_TO_DATE(CONCAT(myDate,'01'),'%Y%m%d')
FROM myTable
Use STR_TO_DATE:
From mysql.com:
STR_TO_DATE(str,format)
This is the inverse of the DATE_FORMAT() function. It takes a string str and a format string format. STR_TO_DATE() returns a DATETIME value if the format string contains both date and time parts, or a DATE or TIME value if the string contains only date or time parts.
The date, time, or datetime values contained in str should be given in the format indicated by format. For the specifiers that can be used in format, see the DATE_FORMAT() function description. If str contains an illegal date, time, or datetime value, STR_TO_DATE() returns NULL. Starting from MySQL 5.0.3, an illegal value also produces a warning.
Range checking on the parts of date values is as described in Section 11.3.1, “The DATETIME, DATE, and TIMESTAMP Types”. This means, for example, that “zero” dates or dates with part values of 0 are allowed unless the SQL mode is set to disallow such values.
mysql> SELECT STR_TO_DATE('00/00/0000', '%m/%d/%Y');
-> '0000-00-00'
mysql> SELECT STR_TO_DATE('04/31/2004', '%m/%d/%Y');
-> '2004-04-31'
Get the year:
SUBSTRING(field FROM 2 FOR 2)
Get the month:
SUBSTRING(field FROM -2 FOR 2)
Compose the date:
CONCAT(SUBSTRING(field FROM -2 FOR 2), '/01/', SUBSTRING(field FROM 2 FOR 2))
This will convert from YYYYMM to MM/01/YY.
To be clear: if you're looking for method to convert some value of type Varchar/Text to value of type Date than solutions are:
using CAST function
CAST(LEFT('201205',4)||'-'||SUBSTRING('201205' FROM 5 FOR 6)||'-01' AS DATE)
starting from OpenOffice 3.4 (HSQLDB 2.x) new Oracle-like function TO_DATE supposed to be available
TO_DATE('201205','YYYYMM')
in addition to the written i can mention that you also can construct a string with ANSI/ISO 'YYYY-MM-DD' formatted representation of the date,- Base will acknowledge that and succesfully convert it to the Date type if necessary (e.g. INSERTing in Date typed column etc.)
Here is doc's on HyperSQL and highly recommended OO Base guide by Andrew Pitonyak