I have a column in my sqlite table which is string and has the following format
2011-09-06 18:34:55.863414
You can see that it identifies date and time. I'd like to construct a query that will
delete all records that are older than certain date and time.
Is this possible?
Since your date is already in the best format (largest time-period values to smallest)
DELETE FROM myTable
WHERE myDateField < '2011-09-06 18:34:55.863414'
BTW -- dates are strings in sqllite, AFAIK (which is why the format matters -- biggest values to smallest, so it works alphabetically too). IF you want to treat them as dates, you can use functions. Some good examples here: http://sqlite.org/lang_datefunc.html
DELETE FROM tablename WHERE columnname < '2011-09-06 18:34:55.863414'
See:
http://www.sqlite.org/lang_datefunc.html
Related
The sqlite timestamp here is 18 digits, but how can one know its specific date. 132079170460000000 should correspond to July 2019, but this year cannot be obtained regardless of interpretation or other conversions. I want to get time like 2019-07-30 13:23:40.
This is sqllite timestamp, but product specific model does not know,only know that this timestamp is 18-digit just like these:
132079170420000000
132079218060000000
If 132089746940000000 is equivalent to "2019-07-31 13:42:31" as mentioned in the comments, then try this:
SELECT datetime( DateColumnWith18Digits / 1.0E11 + 1137798.60179213 )
FROM SomeTable
If the example you shared was just a random value, this technique might still work, but you'll need to find the offset factor. The conversion assumes that the 18-digit value is the number of milliseconds since some epoch. I simply assumed that one of the comments contained a valid equivalence and found the offset to match the Julian date value.
The reverse encoding would be like
SELECT (julianday('2019-07-31 13:42:31') - 1137798.60179213) * 1E11
I'm using SQLite3 and trying to query for recent rows. So I'm having SQLite3 insert a unix timestamp into each row with strftime('%s','now'). My Table looks like this:
CREATE TABLE test(id INTEGER PRIMARY KEY, time);
INSERT INTO test (time) VALUES (strftime('%s','now')); --Repeated
SELECT * FROM test;
1|1516816522
2|1516816634
3|1516816646 --etc lots of rows
Now I want to query for only recent entries, for example, I'm trying to get all rows with a time within the last hour. I'm trying the following SQL query:
SELECT * FROM test WHERE time > strftime('%s','now')-60*60;
However, that always returns all rows regardless of the value in the time column. I really don't know what's going on.
Also, if I put WHERE time > strftime('%s','now') it'll return nothing (which is expected) but if I put WHERE time > strftime('%s','now')-1 then it'll return everything. I don't know why.
Here's one more example:
sqlite> SELECT , strftime('%s','now')-1 AS window FROM test WHERE time > window;
1|1516816522|1516817482
2|1516816634|1516817482
3|1516816646|1516817482
It seems that SQLite3 thinks the values in the middle column are greater than the values in the right column!?
This isn't at all what I expect. Can someone please tell me what's going on? Thanks!
The purpose of strftime() is to format values, so it returns a string.
When you try to do computations with its return value, the database must convert it into a number. And numbers and strings cannot be compared directly with each other.
You must ensure that both values in a comparison have the same data type.
The best way to do this is to store numbers in the table:
INSERT INTO test (time)
VALUES (CAST(strftime('%s','now') AS MAKE_THIS_A_NUMBER_PLEASE));
(Or just declare the column type as something with numeric affinity.)
LEAST(DATE(CAP_REMEDIATION.DATE_OF_AUDIT),
DATE(CAP_REMEDIATION.START_DATE_REQUEST))
I am using this to find the minimum date between two dates.
Teradata didn't define LEAST/GREATEST for the date/time types (stupid, at least fixed in TD16.10).
If it's only two columns the easiest way is good ol' CASE:
CASE WHEN CAP_REMEDIATION.DATE_OF_AUDIT < CAP_REMEDIATION.START_DATE_REQUEST
THEN CAP_REMEDIATION.DATE_OF_AUDIT
ELSE CAP_REMEDIATION.START_DATE_REQUEST
END
If the datatypes are actually timestamps and you want a date:
CAST(previous_case_expression AS DATE)
I have a sqlite3 table with dates stored as text not null with the format MM-DD-YY, and have been doing most of my manipulation in Java by iterating through the cursor, however, it's proving to be a bit ugly/cumbersome, and I was wondering if there's any way to do an update statement in sqlite3 to increment/decrement all records by a certain number of days. I'm mostly having trouble figuring out how to convert my text column into a format that I can use with something along the lines of datetime(myDate, '+1 Day');. Can anybody point me in the right direction? Thanks guys!!
The documentation of the built-in date functions documents the supported date format:
YYYY-MM-DD
You should store your date values in this format.
If you cannot do this, you can use substr() to extract the fields of the date and convert it into the supported format.
I have a table that includes a 'LastUpdated' column that is generated when the row is inserted using Sqlite's datetime('now') function.
How do I write a Select statement that finds all rows with 'LastUpdated' more than 100 days old?
I think it's a variant of:
SELECT * FROM Table WHERE (DATETIME('Now')-100 Days) > LastUpdated
But I'm unsure of:
a) How to specify the 100 Days?
b) Whether I can actually compare datetimes like this or if I first have to convert DATETIME('Now') to a string?
c) DATETIME('Now') results in UTC time, correct? I think so from my reading of the documentation, but it was a little confusing...
Figured it out--I didn't see all the handy modifiers at the bottom of the SQLite Datetime Documentation.
A bunch of helpful examples there demonstrating addition/subtraction of any datetime unit (years, months, hours, seconds, etc)
SELECT * FROM Table WHERE (DATETIME('Now','-100 Days') > LastUpdated