I need to create a date from the year and the day number of the year in sqlite, I have seen that for mysql there is the MAKEDATE () function, which does exactly what I need, but in sqlite it doesn't work.
How could I solve this?
For example:
I have a year 2020 and number day 20, i expected this output = '2020-04-01'
I m not sure about where you are going to use, but Sqlite does provide modifiers that you can use for the various date-time functions.
Check this link. It is not possible to provide the detail explanation here so I m referring to the link.
Below is one such query I prepared using those modifiers, this query calculates the date, by changing now to start of year and adding 20 days (NNN days),
SELECT DATE('now','start of year','20 days');
You can check this query output here.
So natively Sqlite supports this, but I m not sure about the application you will be using SQLite with supports this or not.
Related
I need to create simple query which will show all contracts which will expire in next 3 months. I know how to do that with SQL, but how to do that in Visual Studio when I create query. I added data source Contract table. Added range. Column where is date about expiring is VALIDTO.
So, something to write up in value, or how to do that ?
Solved with two ranges on VALIDTO column. Used (MonthRange(0,3)) with (Day(0)) formulas.
I am using sqlite for local database in mobile and in my database. i want to know that
How to get current date format in SQLITE? I want to get date in the next format: MM/dd/yyyy
To get the current date you can use:
SELECT date('now');
Note: This is NOT a server date, it's the same time you get if you query the date and time directly from your application because SQLITE runs in-process.
It's mostly useful for putting a current time into a table or for some simple calculations if your language's date processing is very poor.
To do the calculations see the SQLITE Documentation
See the docs for formatting too for example:
SELECT strftime('%Y-%m-%d %H:%M:%S', datetime('now'))
According to the SQLite documentation as of this writing (3/30/2020), in the section titled "The DEFAULT clause", it is recommended that a constant value be used instead of a sub-query.
In my experimentation, I also ran into issues with the SQLite CREATE TABLE statement that was generated during model creation by EF Core 3.0 when using SELECT datetime('now'). The SQLite data provider complained of a syntax error when using a SELECT statement within the CREATE table statement. As such, I would recommend using the CURRENT_TIMESTAMP keyword.
for your concrete case, this is what you need:
strftime('%m/%d/%Y',date('now'))
I have never used Informix before and I'm trying to write a query that will return records over the last 365 days.
Here is the query I have been trying to use:
Select * from Visit where vis_mod_dt between today-365 and today;
That returns no records even though I know that there is data for the last 365 days. I am guessing that the vis_mod_dt in not a true date column, although it displays as '12/31/1899' I have tried to cast this column using:
select * from visit where date(vis_mod_dt) between today-365 and today;
This still returns no data.
Any ideas?
Informix DATE format
Be aware that the date 1899-12-31 corresponds to the internal date representation of zero (0). That is, internally, Informix stores DATE values in a 4-byte integer, and counts the number of days since 1899-12-31, so Day 1 was 1900-01-01 (and since it knows that 1900 was not a leap year, Day 60 was 1900-03-01).
That fact makes me worry about what is in your table. However, if the data in your table cannot be converted to a DATE upon request, normally you would get an error.
What is your table schema?
It would be sensible for you to establish the schema either using DB-Access and the Info/Tables option, or use DB-Schema:
dbschema -d dbase -t visit
The DB-Schema output is more suitable for adding to your question.
The query expressions using 'TODAY-365' and 'TODAY' should work fine - if there is data to select.
DBDATE environment variable
There is an environment variable, DBDATE, that you may need to set to get things to work - to convert from a string representation to dates. Since you are probably based in the UK (from your icon), then you may want and need to set the value of DBDATE to:
export DBDATE=DMY4/
This says that dates consist of the day, the month, a 4-digit year and the '/' is used as the preferred separator. You won't be surprised to learn that the presumed default value is usually 'MDY4/', for US format; I use 'Y4MD-' habitually, so I see DATE value the same as DATETIME YEAR TO DAY, which is the ISO 8601:2004 notation for a date. (It has many benefits: it is unambiguous, and naive sorting algorithms sort such dates into date order.) There's actually a lot of mechanism in the background in IDS (IBM Informix Dynamic Server - which, I assume, is the DBMS that you are using; there are some alternatives that are also Informix DBMS) such that strings with 2-digit dates will usually be converted correctly (but they are ambiguous and undesirable), and separators other than '/' will be recognized on input, but the slash will be used on 'output' (when converting DATE to string).
Information needed to improve the answer to this question - 1st Edition.
If what is here does not help, then I recommend editing your question to include:
The table schema.
A few (2-4) rows of data that you think should be selected but aren't.
Platform and version information. It can help to have the version down to the level of detail of IDS 11.50.FC4W1; occasionally it matters. Most usually, the first three digits are what affect things, of course.
If your table is big (many columns), try to select the key columns (vis_mod_dt is by far the most important one). Ideally, you won't need any scroll bars in the display.
Make sure you don't include any sensitive information.
Information needed to improve the answer to this question - 2nd Edition
I will help you if you pay attention to the questions I ask you. I cannot help you if you do not pay attention to the questions I ask. And please edit your question rather than adding information as an 'answer'.
What is the table schema? What is the output from:
SELECT t.tabid, t.tabname, c.colno, c.colname, c.coltype, c.collength
FROM "informix".systables AS t, "informix".syscolumns AS c
WHERE t.tabid = c.tabid
AND t.tabname = "visit"
ORDER BY t.tabid, c.colno;
What do you get from:
SELECT TODAY, TODAY-365 FROM "informix".systables WHERE tabid = 1;
Do you have the environment variable DBDATE set? If so, what is its value?
Do you have the environment variables CLIENT_LOCALE or DB_LOCALE set? If so, what are their values?
Which version of Informix are you using?
Which platform are you using it on?
Which language or tool are you using to run the query.
Note: if you cannot copy'n'paste the queries above, then you probably do not need to include the quoted '"informix".' attributes on the system catalog; however, as written, the queries will work on any extant Informix database - OnLine 5.x, SE 5.x or 7.x, IDS 7.x, XPS 8.x, IDS 9.x or 10.x or 11.x - and any mode of database (unlogged, logged, MODE ANSI). I'd use the JOIN notation except that some of the older versions don't support it - though you have to be on very old versions for that to be a problem.
This is a little confusing, because when I run the following, I get data:
select count(*) from visit where vis_mod_dt between "10/01/2008" and "10/01/2009"
how about unloading the table to ascii file, examine the unloaded vis_mod_dt values to see if they conform to DBDATE=MDY4 (mmddyyyy) format?.. if they do, ALTER vis_mod_dt to TYPE DATE if it's not a DATE column, then LOAD the unloaded table back in.
the: "BETWEEN today-365 AND today" part of your SELECT statement works for me in my apps.
My table contains Birthdate field which has datatype as datetime.
I want to get all records having birthday today.
How can I get it?
Try this query:
SELECT * FROM mytable
WHERE strftime('%m-%d', 'now') = strftime('%m-%d', birthday)
Having a special datetime type has always seemed like unnecessary overhead to me, integers are fast, flexible, and use less space.
For general datetime values use Unix Epoch timestamps. Easy to work with, extremely flexible, as well as timezone (and even calender!) agnostic. (I recently wrote an article on using them, which I really have to plug...)
That said, if you're only interested in dates in the Gregorian calendar you may want to use a large integer in the following format: YYYYMMDD, eg 19761203. For you particular usage you could even create a four digit integer like MMDD, say 1703 — that's got to result in fast selects!
SQLite has very poor support for storing dates. You can use the method suggested by Nick D above but bear in mind that this query will result in full table scan since dates are not indexed correctly in SQLite (actually SQLite does not support dates as a built-in type at all).
If you really want to do a fast query then you'll have to add a separate (integral) column for storing the birth day (1-31) and attach an index for it in the database.
If you only want to compare dates then you can add a single (INTEGER) column that will store the date UTC value (but this trick won't allow you to search for individual date components easily).
Good Luck
I'm trying to pull and format timestamp from my SQLite db. In my reading, it seems that SQLite formatting is extremely limited compared to date formatting conversion available to PHP. I have this query coming from javascript:
SELECT strftime('%m %d, %Y', timestamp) AS saveddate
And it returns:
03 03, 2009
I'm trying to get it to return:
March 3, 2009
Any suggestions?
SQLite does not support month names, sadly. You will have to convert it to a month name either using a lookup table, a case statement, or a switch on the presentation layer.
It's absolutely true that SQLite is focused on the functionality that belongs in the data storage layer and NOT on functionality that belongs in the user interface, like formatting dates with month names and the like. I strongly suggest that you take this as a very helpful hint to keep each kind of functionality in its proper layer!-).
If you're absolutely keen to misplace UI functionality in the data storage layer, this can to some extent be shoehorned in, e.g. by writing your own formatting functions in C and hooking them up in SQLite, or going through incredibly clumsy SQL gyrations, but I cannot imagine ANY use case where that would be worth the bother.
Short month name
substr ("--JanFebMarAprMayJunJulAugSepOctNovDec", strftime ("%m", thedate) * 3, 3)
Full month name
rtrim (substr ("January--February-March----April----May------June-----July-----August---SeptemberOctober--November-December", strftime ("%m", thedate) * 9 - 8, 9))
The dashes are only used to make it clear on the page. Replace them with spaces.