I am trying to insert a datetime value into a SQLite database. It seems to be sucsessful but when I try to retrieve the value there is an error:
<Unable to read data>
The SQL statements are:
create table myTable (name varchar(25), myDate DATETIME)
insert into myTable (name,mydate) Values ('fred','jan 1 2009 13:22:15')
The format you need is:
'2007-01-01 10:00:00'
i.e. yyyy-MM-dd HH:mm:ss
If possible, however, use a parameterised query as this frees you from worrying about the formatting details.
The way to store dates in SQLite is:
yyyy-mm-dd hh:mm:ss.xxxxxx
SQLite also has some date and time functions you can use. See SQL As Understood By SQLite, Date And Time Functions.
You have to change the format of the date string you are supplying in order to be able to insert it using the STRFTIME function. Reason being, there is no option for a month abbreviation:
%d day of month: 00
%f fractional seconds: SS.SSS
%H hour: 00-24
%j day of year: 001-366
%J Julian day number
%m month: 01-12
%M minute: 00-59
%s seconds since 1970-01-01
%S seconds: 00-59
%w day of week 0-6 with sunday==0
%W week of year: 00-53
%Y year: 0000-9999
%% %
The alternative is to format the date/time into an already accepted format:
YYYY-MM-DD
YYYY-MM-DD HH:MM
YYYY-MM-DD HH:MM:SS
YYYY-MM-DD HH:MM:SS.SSS
YYYY-MM-DDTHH:MM
YYYY-MM-DDTHH:MM:SS
YYYY-MM-DDTHH:MM:SS.SSS
HH:MM
HH:MM:SS
HH:MM:SS.SSS
now
Reference: SQLite Date & Time functions
Use CURRENT_TIMESTAMP when you need it, instead OF NOW() (which is MySQL)
Read This: 1.2 Date and Time Datatype
best data type to store date and time is:
TEXT best format is: yyyy-MM-dd HH:mm:ss
Then read this page; this is best explain about date and time in SQLite.
I hope this help you
This may not be the most popular or efficient method, but I tend to forgo strong datatypes in SQLite since they are all essentially dumped in as strings anyway.
I've written a thin C# wrapper around the SQLite library before (when using SQLite with C#, of course) to handle insertions and extractions to and from SQLite as if I were dealing with DateTime objects.
Related
I have a Oracle SQL statement where I have to get the current timestamp as one of the columns. But I dont require the Timezone which CURRENT_TIMESTAMP gives or the AM/PM given by LOCALTIMESTAMP.
I require the current timestamp in 24hr format without the timezone.
Is it possible to get that in Oracle SQL?
It seems you're mixing 2 concepts here: "datatype" and "date format mask".
data type: LOCALTIMESTAMP returns datatype TIMESTAMP and CURRENT_TIMESTAMP returns datatype TIMESTAMP WITH TIME ZONE. TIMESTAMP is similar to DATE but has a higher precision. As usual... checking the docs is worth it.
date format mask: determines how you display the date information. Americans can't read 24 hour format, the rest of the world is confused by AM/PM. Fortunately, you can decide how you want to display the date as explained in the oracle docs.
If you just want to return the current date in 24 hour format you could do something like:
SELECT
TO_CHAR(SYSDATE,'DD-MON-YYYY HH24:MI:SS') as mydate,
<other columns>
FROM
<table_name>
If you need the date to be more precise and you require fractional seconds then you can use SYSTIMESTAMP instead of DATE with a format mask 'DD-MON-YYYY HH24:MI:SS.FF9'
I have a dataset with column named "msg_dateStr" which contains user's accessing date and time.
I tried to split it into two different columns; date and time, and I did SELECT date(msg_dateStr, 'localtime') as Year
but it returns null straight.
I don't know why this happens and how I can make sure something went wrong.
Any advice will be appreciated.
The date to be used by the Date and Time Functions such as date MUST be in a format that is recognised by SQLite for a useful result. Recognised formats are (extract from the link above) :-
Time Strings
A time string can be in any of the following formats:
YYYY-MM-DD
YYYY-MM-DD HH:MM
YYYY-MM-DD HH:MM:SS
YYYY-MM-DD HH:MM:SS.SSS
YYYY-MM-DDTHH:MM
YYYY-MM-DDTHH:MM:SS
YYYY-MM-DDTHH:MM:SS.SSS
HH:MM
HH:MM:SS
HH:MM:SS.SSS
now
DDDDDDDDDD
You need to ensure that the data is saved accordingly or alternately (but not recommended at all) reformat the column via SQL (e.g. using the substr built-in function).
I currently have a timestamp in this format Tue Jun 03 17:17:05 +0000 2014 in one column in my table. I want to count the number of records happening in specific intervals (15 minutes). I have tried to follow the answer found in Group records by time. Although my timestamp is in a different format and I haven't seen any support function available in SQLite to convert this. Is this possible in SQL?
The SQLite date and time functions can be used to convert a timestring to a canonical format, or to a Julian Day Number. Unfortunately, the SQLite date and time functions only accept timestring in a limited number of formats:
YYYY-MM-DD
YYYY-MM-DD HH:MM
YYYY-MM-DD HH:MM:SS
YYYY-MM-DD HH:MM:SS.SSS
YYYY-MM-DDTHH:MM
YYYY-MM-DDTHH:MM:SS
YYYY-MM-DDTHH:MM:SS.SSS
If your timestring format has fixed field widths, you can use the substr function and the || string concatenation operator to convert it to a format SQLite understands. You'll have to use a case expression to convert the month names to numbers; here's an example.
You may use NEW_TIME in Oracle to convert the time to a specific timezone. Here is an example. This example is converting SYSDATE from PDT to GMT.
SELECT NEW_TIME (SYSDATE, 'PDT', 'GMT') FROM DUAL;
This thread is detailing how to add required minutes to your timestamp.
I am trying to extract the date and time from a field in Teradata.
The field in question is:
VwNIMEventFct.EVENT_GMT_TIMESTAMP
Here is what the data look like:
01/02/2012 12:18:59.306000
I'd like the date and time only.
I have tried using EXTRACT(Date, EXTRACT(DAY_HOUR and a few others with no success.
DATE_FORMAT() does not appear to work since I'm on Teradata.
How would I select the date and time from VwNIMEventFct.EVENT_GMT_TIMESTAMP?
If the datatype of EVENT_GMT_TIMESTAMP is a TIMESTAMP, it's simple Standard SQL:
CAST(EVENT_GMT_TIMESTAMP AS DATE)
CAST(EVENT_GMT_TIMESTAMP AS TIME)
If it's a CHAR you need to apply a FORMAT, too:
CAST(CAST(EVENT_GMT_TIMESTAMP AS TIMESTAMP FORMAT 'dd/mm/yyyyBhh:mi:SS.s(6)') AS DATE)
CAST(CAST(EVENT_GMT_TIMESTAMP AS TIMESTAMP FORMAT 'dd/mm/yyyyBhh:mi:SS.s(6)') AS TIME)
Edit:
For simply changing the display format you need to add a FORMAT and a CAST to a string:
CAST(CAST(EVENT_GMT_TIMESTAMP AS FORMAT 'YYYYMMDDHHMI') AS CHAR(12))
or
CAST(CAST(EVENT_GMT_TIMESTAMP AS FORMAT 'YYYYMMDDHHMISS') AS CHAR(14))
If you don't care about display, just want to truncate the seconds:
EVENT_GMT_TIMESTAMP - (EXTRACT(SECOND FROM EVENT_GMT_TIMESTAMP) * INTERVAL '1.000000' SECOND)
Working with timestamps is a bit tricky :-)
I know this is an old topic, but I've struggled with this too. Try:
CAST(EVENT_GMT_TIMESTAMP AS TIMESTAMP(0))
The result will be
01/02/2012 12:18:59
The datatype will still be timestamp, but it will just be the date and time with no microseconds (looks just like a datetime object in Microsoft SQL).
I've just now started working with SQL; I need to represent some information in some tables, date and time being two of them.
I want to know, if there is a better data type to represent date and time than varchar() or numeric().
Are there any SQL primitives to represent date and time?
Yes there are date time specific data types for most SQL database implementations.
Exact syntax depends on the RDMS vendor, but here are some examples for the very popular Microsoft SQL Server and Oracle (previously Sun) MySQL.
SQL Date Functions
MySQL comes with the following data types for storing a date or a date/time value in the database:
DATE - format YYYY-MM-DD
DATETIME - format: YYYY-MM-DD HH:MM:SS
TIMESTAMP - format: YYYY-MM-DD HH:MM:SS
YEAR - format YYYY or YY
SQL Server comes with the following data types for storing a date or a date/time value in the database:
DATE - format YYYY-MM-DD
DATETIME - format: YYYY-MM-DD HH:MM:SS
SMALLDATETIME - format: YYYY-MM-DD HH:MM:SS
TIMESTAMP - format: a unique number
Or you can search for other database implementations. Ex:
"Oracle date time data type sql"
You might find:
Overview of Datetime and Interval Datatypes and Time Zone Support
It depends which flavor you're working with, but most variations of SQL offer date, smalldate, datetime, datetimeoffset, etc.
It really just depends on how you'd like to show the date, and how much information you'd like to show.
The most common form is datetime, and is explained (along with all others) at MSDN Transact-SQL