I've received a SQLite file with .db extension.
Opening it, I have a column with serial numbers: i.e. 1600414704594 (that should correspond to 2020-10-09 and whatsover time)
The db comes from outside and I don't know how that date field has been built.
Could you suggest me a query to get a valid date/time from that db column ?
I've tried reading this post but none of the given solution returned me a valid (and actual) date, please help me.
It looks like an Unix time in milliseconds. SQLite's unixepoch modifier expects it in seconds. The conversion is fairly easy :
SELECT DATETIME(1600414704594 / 1000, 'unixepoch')
2020-09-18 07:38:24
Related
I'm trying to write a query for an MS Access 2007 connection to a MySQL database through ODBC. Everything's working fine, and the query does what I want it to do. The part that I'm hung up on is that I'm stuck asking the user for unix epoch time, instead of a regular date.
I looked up a bunch of references for MS Access, and while there are a number of date conversion functions I can use in the SQL call, I can't find any that I can use to convert from a normal date -> unix epoch date.
What I would like, and I assume this works, is to ask the user for the date in a much kinder fashion (a human readable date), and then convert it into unix epoch date. Now that I think about it, I guess my other option is to convert the unix epoch dates in the database after drawing them out with the SQL query, but I'd rather convert the user's input if at all possible as there is less of that input so I wouldn't have to do as much work.
SELECT TOP 5 Count( * ) AS [Number of visits by language], login.lang AS [Language]
FROM login, reservations, reservation_users
WHERE (reservations.start_date Between [Starting unix epoch time] And [Ending unix epoch time]) And reservations.is_blackout=0 And reservation_users.memberid=login.memberid And reservation_users.resid=reservations.resid And reservation_users.invited=0
GROUP BY login.lang
ORDER BY Count( * ) DESC;
Don't know if this is going to work (don't have Access to confirm), but try the suggestion from here:
http://weblogs.sqlteam.com/jeffs/archive/2007/04/13/format-date-sql-server.aspx
which is to use:
DATEDIFF(second, '1 Jan 1970', tbl.LastChangeDate)
This is from some of the comments.
EDIT: See the comment from Remou.
Using MS 2010 I found this works: DateAdd("s",([epoch timestamp]-21600),#1/1/1970#)
http://www.pcreview.co.uk/forums/convert-epoch-date-t2324318.html
I have a sqlite db (it is the spiceworks db) and I am mapping the tables to grails domain classes. There is a table in particular that is in a datetime format (yyyy-MM-dd HH:mm:ss). An example of such a date in the db for anyone who wants to verify would be: 2015-06-26 15:32:39
I created the domain class and mapped my properties to the columns. Let grails generate the views so that they are default. When I try to get to the index page I get:
URI
/spiceworks/weeklyReportItem
Class
java.text.ParseException
Message
Unparseable date: "2015-06-26 15:32:39" does not match (\p{Nd}++)\Q-\E(\p{Nd}++)\Q-\E(\p{Nd}++)\Q \E(\p{Nd}++)\Q:\E(\p{Nd}++)\Q:\E(\p{Nd}++)\Q.\E(\p{Nd}++)
I've used MSSQL datetimes in the past and have never ran into this issue. In the database, the data type for the problematic column is datetime. Anyone know what's going on?
EDIT: I only have Read permissions on the db and the spiceworks source code isn't open source.
If you look at that regular expression, you'll see it's looking for a ISO8601 timestamp formatted like YYYY-MM-DD HH:mm:SS.SSS - in other words, it needs a decimal seconds, and you're just providing whole seconds.
An easy fix would be to update every existing value in the relevant column by appending '.000' to it, and update the insertion routines to do the same.
If you refer to the sqlite date time functions, there's a %f format specifier for strftime() that can be used to produce fractional seconds that might be helpful if you're building the timestamp directly in an insert query.
In the database, the data type for the problematic column is datetime
Sqlite3 doesn't have a datetime type. The timestamps you're storing are strings. More information.
I am working on a SQLite Database which contains a column which stores value in format yyyy-MM-dd HH:mm:ss. Now I need to create a filter to select rows with filter as this datetime column.
Query:
Select * from tbl_locations where datetime >= '2013-09-11 00:00:00' and datetime <='2013-09-13 00:00:00'
Above query is returning null set despite containing values in this slot(which I verified using select statement without filter.)
Any suggestion how can i get the required data set?
Perhaps this excerpt from the SQLite documentation will help you:
1.2 Date and Time Datatype
SQLite does not have a storage class set aside for storing dates and/or times. Instead, the built-in Date And Time Functions of SQLite are capable of storing dates and times as TEXT, REAL, or INTEGER values:
TEXT as ISO8601 strings ("YYYY-MM-DD HH:MM:SS.SSS").
REAL as Julian day numbers, the number of days since noon in Greenwich on November 24, 4714 B.C. according to the proleptic Gregorian calendar.
INTEGER as Unix Time, the number of seconds since 1970-01-01 00:00:00 UTC.
Applications can chose to store dates and times in any of these formats and freely convert between formats using the built-in date and time functions.
The date and time functions that you can use in your SQL to build your query are documented at http://www.sqlite.org/lang_datefunc.html
Ok, I tested this out in MySQL but hopefully it will work. I had a table that used timestamps, and changed the column to be of type text. Then I tried the following SQL query and got the same results that I normally would (besides trailing decimals)
SELECT timestamp(stock_quote_timestamp)
FROM stock.stock_quote
WHERE stock_quote_timestamp < timestamp('2013-10-07 11:05:30')##high_date
AND stock_quote_timestamp > timestamp('2013-10-03 14:09:03');##low_date;
So basically, just convert your text statements to timestamps so that they compare correctly. Oh, and you'll also need to state what else you're SELECTing, or you could do a compound select statement: SELECT *, timestamp(stock_quote_timestamp)...
I cannot seem to figure out why datetime does not work for me on some data I imported from CSV. I have a column, TIMESTAMP, which is of type datetime.
Select TIMESTAMP from GPS limit 1 <-This gives me a time, "6/29/2009 00:00:00"
Select datetime(TIMESTAMP) from GPS limit 1 <- This gives me a pink field in SQLite manager, which seems empty.
Select datetime('now') from GPS limit 1 <- This gives me the current date and time. ("2012-12-19 20:45:17") It is formatted differently than my other data - is there a datatype issue?
What is going on? Did my "Timestamp" data not actually get converted into a DATETIME object? Why is it stored as text? Is there a way to fix this?
SQLite does not have a native date/time type; dates are stored either as numbers or as strings.
To be understood by SQLite's built-in date functions, date strings must have a format like yyyy-mm-dd hh:mm:ss.
I have a SQLite database where I store the dates as ticks. I am not using the default ISO8601 format. Let's say I have a table defined as follows:
CREATE TABLE TestDate (LastModifiedTime DATETIME)
Using SQL, I wish to insert the current date and time. If I execute any of the below statements, I end up getting the date and time stored as a string and not in ticks.
INSERT INTO TestDate (LastModifiedTime) VALUES(CURRENT_TIMESTAMP)
INSERT INTO TestDate (LastModifiedTime) VALUES(DateTime('now'))
I have looked at the SQLite documenation, but I do not seem to find any option to obtain the current timestamp in ticks.
I can of course define a parameter in C# and store the value as a System.DateTime. This does result in the datetime getting stored to the database in ticks.
What I would like to do is be able to insert and update the current timestamp directly from within the SQL statement. How would I do this?
Edit:
The reason I want the data stored as ticks in the database, is that the dates are stored in the same format as stored by the ADO.Net data provider, and so that when the data is also queried using the ADO.Net provider it is correctly retrieved as a System.DataTime .Net type.
This particular oddity of SQLite caused me much anguish.
Easy way - store and retrieve as regular timestamp
create table TestDate (
LastModifiedTime datetime
);
insert into TestDate (LastModifiedTime) values (datetime('now'));
select datetime(LastModifiedTime), strftime('%s.%f', LastModifiedTime) from TestDate;
Output: 2011-05-10 21:34:46|1305063286.46.000
Painful way - store and retrieve as a UNIX timestamp
You can use strftime to retrieve the value in ticks. Additionally, to store a UNIX timestamp (roughly equivalent to ticks), you can can surround the number of seconds in single-quotes.
insert into TestDate (LastModifiedTime) values ('1305061354');
SQLite will store this internally as some other value that is not a UNIX timestamp. On retrieval, you need to explicitly tell SQLite to retrieve it as a UNIX timestamp.
select datetime(LastModifiedTime, 'unixepoch') FROM TestDate;
To store the current date and time, use strftime('%s', 'now').
insert into TestDate (LastModifiedTime) VALUES (strftime('%s', 'now'));
Full example:
create table TestDate (
LastModifiedTime datetime
);
insert into TestDate (LastModifiedTime) values (strftime('%s', 'now'));
select datetime(LastModifiedTime, 'unixepoch') from TestDate;
When executed by sqlite3, this script with print:
2011-05-10 21:02:34 (or your current time)
After further study of the SQLite documentation and other information found on date number conversions, I have come up with the following formula, which appears to produce correct results:
INSERT INTO TestDate(LastModifiedTime)
VALUES(CAST((((JulianDay('now', 'localtime') - 2440587.5)*86400.0) + 62135596800) * 10000000 AS BIGINT))
Seems like a painful way to produce something that I would expect to be available as a built-in datetime format, especially that the database supports the storing of datetime values in ticks. Hopefully, this becomes useful for others too.
Update:
The above formula is not perfect when it comes to daylight savings. See section Caveats And Bugs in SQLite docs regarding local time calculation.
The following will return the number of milliseconds since the UNIX Epoch:
SELECT (strftime('%s', 'now') - strftime('%S', 'now') + strftime('%f', 'now')) * 1000 AS ticks
It works by grabbing the number of seconds since the Unix Epoch (%s), subtracting the number of seconds in the current time (%S), adding the number of seconds with decimal places (%f), and multiplying the result by 1000 to convert from seconds to milliseconds.
The subtraction and addition are to add precision to the value without skewing the result. As stated in the SQLite Documentation, all uses of 'now' within the same step will return the same value.