I have an integer date column "date_created" storing values like...
20180527, 20191205, 20200208
And am wondering what the best way to parse as a date is so I could do something like this in a query...
select * from table where formatted(date_created) > formatted(date_created) - 90
(to return everything within the last 90 days)
I've found some similar examples that convert from date ints representing seconds or milliseconds, but none where the columns are essentially date strings stored as integers.
Appreciate any thoughts on the best way to achieve this
And am wondering what the best way to parse as a date is so I could do something like this in a query...
You can convert "date as a number" (eg. 20180527 for May 27, 2018) using the following:
cast to varchar
parse_datetime with appropriate format
cast to date (since parse_datetime returns a timestamp)
Example:
presto> SELECT CAST(parse_datetime(CAST(20180527 AS varchar), 'yyyyMMdd') AS date);
_col0
------------
2018-05-27
However, this is not necessarily the best way to query your data. By adapting your search conditions to the format of your data (and not vice versa), you can potentially benefit from predicate push down and partition pruning. See #GordonLinoff answer for information how to do this.
You can do the comparison in the world of integers or of dates. You might as well convert the current date minus 90 days to a number:
select t.*
from t
where date_created >= cast(date_format(current_date - interval '90 day',
'%Y%m%d'
) as int
);
the below query is index friendly for any database since it does not use function on indexed column
select * from table where date_created > timestamp (formatted(date) - 90)
In addition, suppose we have date in format 20211011_1234 and we want one month older date and want back the original format, we can use the following formatting to convert date to int and vice versa.
select cast(date_format(
CAST(parse_datetime(cast(
split_part('20211011_1234', '_', 1) as varchar), 'yyyyMMdd')
AS date) - interval '30' day ,'%Y%m%d') as int) as column_name
Related
I have a timestamp with time zone column within which I'd like to run a query returning all matching dates. eg. I want all rows which have a timestamp with date 2019-09-30. I'm trying something like this but haven't been able to figure it out:
SELECT * FROM table WHERE
x='1277' AND
date='2019-09-30 21:40:01.316240 +00:00'::DATE;
There are two options:
range search:
WHERE timestampcol >= TIMESTAMPTZ '2019-09-30'
AND timestampcol < (TIMESTAMPTZ '2019-09-30' + INTERVAL '1 day')
The proper index to make this fast is
CREATE INDEX ON atable (timestampcol);
conversion to date:
WHERE CAST(timestampcol AS date) = '2019-09-30'
The proper index to make this fast is
CREATE INDEX ON atable ((CAST(timestampcol AS date)));
Both methods work equally well. The second method has a shorter WHERE clause, but a specialized index that maybe no other query can benefit from.
You can use such a collation among your date converted column value and fixed date value :
with tab( x, date ) as
(
select 1277, '2019-09-30 21:40:01.316240 +00:00'::timestamp with time zone union all
select 1278, '2019-09-29 21:40:01.316240 +00:00'::timestamp with time zone
)
select *
from tab
where date::date = date'2019-09-30';
Demo
I am not familiar with postgresql, but the following page https://www.postgresql.org/docs/9.1/datatype-datetime.html indicates that there is an optional precision value p that is used to specify the number of fractional digits retained in the seconds field. How was the data type configured for your date field? Is the timestamp column being stored as an eight byte integer or a floating-point number? If the later, the effective limit of precision might be less than 6. All of this info is on the above linked page.
You have several options, as they have been mentioned, and may vary depending on the data type of your field named "date".
For example,
Turn your field to date, returning format 'yyyy-mm-dd':
SELECT * FROM table WHERE x='1277' AND date::DATE='2019-09-30';
"date" just after field name.
Convert it to char and retrieve 10 characters:
SELECT * FROM table WHERE x='1277' AND LEFT(date::varchar,10)='2019-09-30';
Like the previous:
SELECT * FROM table WHERE x='1277' AND to_char(date,'yyyymmdd')='20190930';
And there are many others. For more specific info, you have to check PostgreSQL documentation to check which one is best for you or post more information in order we can guess more about your problem.
https://www.postgresql.org/docs/9.4/functions-datetime.html
I have a table with a LOAD_STRT_DTM colum. This is a date column and values are like this - 18-JUL-14 08.20.34.000000000 AM.
I want to find the data which came before 5 days.
My logic is -
Select * from Table where 24 *(To_DATE(Sysdate,'DD-MM-YY') - To_DATE(LOAD_STRT_DTM,'DD-MM-YY')) >120
The issue is -
Select (To_DATE(Sysdate,'DD-MM-YY') - To_DATE(LOAD_STRT_DTM,'DD-MM-YY')) from table
This query should give the NumberOfDays between two dates. But this is not working, I Doubt, the issue is because of the format of the LOAD_STRT_DTM colum.
Please let me know where i am doint it wrong.
If your column is DATE datatype everything is ok, just shoot an:
select * from table where LOAD_STRT_DTM > sysdate - 5;
No need to convert dates to DATE datatype.
(To_DATE(Sysdate,'DD-MM-YY') - To_DATE(LOAD_STRT_DTM,'DD-MM-YY'))
You don't have to convert a DATE into a DATE again. IT is already a DATE. You just need to use it for date calculations. You use TO_DATE to convert a STRING into a DATE.
For example, if you have a string value like '18-JUL-14', then you would need to convert it into date using TO_DATE. Since your column is DATE data type, you just need to use as it is.
This is a date column
I want to find the data which came before 5 days.
Simply use the filter predicate as:
WHERE load_strt_dtm > SYSDATE - 5;
NOTE : SYSDATE has both date and time elements, so it will filter based on the time too. If you want to use only the date part in the filter criteria, then you could use TRUNC. IT would truncate the time element.
I have answered a similar question, have a look at this https://stackoverflow.com/a/29005418/3989608
It looks like LOAD_STRT_DTM is a TIMESTAMP rather than a DATE, given the number of decimal points following the seconds. The only thing you have to be cautious about is that Oracle will convert a DATE to a TIMESTAMP implicitly where one of the operands is a TIMESTAMP. So the solution
WHERE load_strt_dtm > SYSDATE - 5
will work; as will
WHERE load_strt_dtm + 5 > SYSDATE
but the following will not:
WHERE SYSDATE - load_start_dtm < 5
the reason being that TIMESTAMP arithmetic produces an INTERVAL rather than a NUMBER.
first convert two dates to same format select datediff(dd,convert(varchar(20),'2015-01-01',112),convert(varchar(20),'01-10-2015',112))
I can't seem to get reliable results from the query against a sqlite database using a datetime string as a comparison as so:
select *
from table_1
where mydate >= '1/1/2009' and mydate <= '5/5/2009'
how should I handle datetime comparisons to sqlite?
update:
field mydate is a DateTime datatype
To solve this problem, I store dates as YYYYMMDD. Thus,
where mydate >= '20090101' and mydate <= '20050505'
It just plain WORKS all the time. You may only need to write a parser to handle how users might enter their dates so you can convert them to YYYYMMDD.
SQLite doesn't have dedicated datetime types, but does have a few datetime functions. Follow the string representation formats (actually only formats 1-10) understood by those functions (storing the value as a string) and then you can use them, plus lexicographical comparison on the strings will match datetime comparison (as long as you don't try to compare dates to times or datetimes to times, which doesn't make a whole lot of sense anyway).
Depending on which language you use, you can even get automatic conversion. (Which doesn't apply to comparisons in SQL statements like the example, but will make your life easier.)
I had the same issue recently, and I solved it like this:
SELECT * FROM table WHERE
strftime('%s', date) BETWEEN strftime('%s', start_date) AND strftime('%s', end_date)
The following is working fine for me using SQLite:
SELECT *
FROM ingresosgastos
WHERE fecharegistro BETWEEN "2010-01-01" AND "2013-01-01"
Following worked for me.
SELECT *
FROM table_log
WHERE DATE(start_time) <= '2017-01-09' AND DATE(start_time) >= '2016-12-21'
Sqlite can not compare on dates. we need to convert into seconds and cast it as integer.
Example
SELECT * FROM Table
WHERE
CAST(strftime('%s', date_field) AS integer) <=CAST(strftime('%s', '2015-01-01') AS integer) ;
I have a situation where I want data from up to two days ago and up until the end of today.
I arrived at the following.
WHERE dateTimeRecorded between date('now', 'start of day','-2 days')
and date('now', 'start of day', '+1 day')
Ok, technically I also pull in midnight on tomorrow like the original poster, if there was any data, but my data is all historical.
The key thing to remember, the initial poster excluded all data after 2009-11-15 00:00:00. So, any data that was recorded at midnight on the 15th was included but any data after midnight on the 15th was not.
If their query was,
select *
from table_1
where mydate between Datetime('2009-11-13 00:00:00')
and Datetime('2009-11-15 23:59:59')
Use of the between clause for clarity.
It would have been slightly better. It still does not take into account leap seconds in which an hour can actually have more than 60 seconds, but good enough for discussions here :)
I had to store the time with the time-zone information in it, and was able to get queries working with the following format:
"SELECT * FROM events WHERE datetime(date_added) BETWEEN
datetime('2015-03-06 20:11:00 -04:00') AND datetime('2015-03-06 20:13:00 -04:00')"
The time is stored in the database as regular TEXT in the following format:
2015-03-06 20:12:15 -04:00
Right now i am developing using System.Data.SQlite NuGet package (version 1.0.109.2). Which using SQLite version 3.24.0.
And this works for me.
SELECT * FROM tables WHERE datetime
BETWEEN '2018-10-01 00:00:00' AND '2018-10-10 23:59:59';
I don't need to use the datetime() function. Perhaps they already updated the SQL query on that SQLite version.
Below are the methods to compare the dates but before that we need to identify the format of date stored in DB
I have dates stored in MM/DD/YYYY HH:MM format so it has to be compared in that format
Below query compares the convert the date into MM/DD/YYY format and get data from last five days till today. BETWEEN operator will help and you can simply specify start date AND end date.
select * from myTable where myColumn BETWEEN strftime('%m/%d/%Y %H:%M', datetime('now','localtime'), '-5 day') AND strftime('%m/%d/%Y %H:%M',datetime('now','localtime'));
Below query will use greater than operator (>).
select * from myTable where myColumn > strftime('%m/%d/%Y %H:%M', datetime('now','localtime'), '-5 day');
All the computation I have done is using current time, you can change the format and date as per your need.
Hope this will help you
Summved
You could also write up your own user functions to handle dates in the format you choose. SQLite has a fairly simple method for writing your own user functions. For example, I wrote a few to add time durations together.
My query I did as follows:
SELECT COUNT(carSold)
FROM cars_sales_tbl
WHERE date
BETWEEN '2015-04-01' AND '2015-04-30'
AND carType = "Hybrid"
I got the hint by #ifredy's answer. The all I did is, I wanted this query to be run in iOS, using Objective-C. And it works!
Hope someone who does iOS Development, will get use out of this answer too!
Here is a working example in C# in three ways:
string tableName = "TestTable";
var startDate = DateTime.Today.ToString("yyyy-MM-dd 00:00:00"); \\From today midnight
var endDate = date.AddDays(1).ToString("yyyy-MM-dd HH:mm:ss"); \\ Whole day
string way1 /*long way*/ = $"SELECT * FROM {tableName} WHERE strftime(\'%s\', DateTime)
BETWEEN strftime('%s', \'{startDate}\') AND strftime('%s', \'{endDate}\')";
string way2= $"SELECT * FROM {tableName} WHERE DateTime BETWEEN \'{startDate}\' AND \'{endDate}\'";
string way3= $"SELECT * FROM {tableName} WHERE DateTime >= \'{startDate}\' AND DateTime <=\'{endDate}\'";
select *
from table_1
where date(mydate) >= '1/1/2009' and date(mydate) <= '5/5/2009'
This work for me
I want to select a varchar field as a date field
For example a field has this value "30.12.2011 21:15:03"
and when i select this
select DATE from TABLE where DATE = '30.12.2011'
i get no result.
You ask about getting the date part of a timestamp field, but what your question is actually about is filtering on the date of a timestamp field. There is a much simpler method of accomplishing that: you can use the knowledge that all the possible timestamps on a specific date won't have any timestamps for different dates between them.
select DATE
from TABLE
where DATE >= '30.12.2011' and DATE < '31.12.2011'
Your edit explains that you haven't got a timestamp field at all. Nevertheless, a similar approach may still work:
select DATE
from TABLE
where DATE LIKE '30.12.2011 %'
Or the Firebird-specific
select DATE
from TABLE
where DATE starting with '30.12.2011 '
Assuming the field is a date field, use the DATE introducer combined with yyyy-mm-dd (or TIMESTAMP with time as well).
So use:
select datefield from sometable where datefield = DATE '2011-12-30'
Technically you can leave off the introducer, but it is 'correcter' in the light of the SQL standard.
Assuming a TIMESTAMP field, you won't get results unless the timestamp is (always) at 00:00:00.0000 (in which case it should have been a DATE instead).
For the comparison to work, you need to use either BETWEEN, eg:
select timestampfield from sometable
where timestampfield BETWEEN '2011-12-30 00:00:00.0000' AND '2011-12-30 23:59:59.9999'
or truncate the timestamp to a date (this may adversely effect performance if the timestamp is indexed, because then the index can no longer be used), eg:
select timestampfield from sometable
where CAST(timestampfield AS DATE) = '2011-12-30'
If the date is stored in a VARCHAR field (which in itself is a bad idea), there are several solutions, first is to handle it as date manipulation:
select varcharfield from sometable
where CAST(CAST(varcharfield AS TIMESTAMP) AS DATE) = '2011-12-30'
The double cast is required if you have a time-component in VARCHARFIELD as well. This assumes dates in the supported format listed below. If you use BETWEEN as above, you can use a single cast to timestamp)
The other solution (as suggested by hvd) is to treat it purely as string manipulation, for example:
select varcharfield from sometable
where varcharfield STARTING WITH '30.12.2011'
This has its own set of problems if you want to select ranges. Bottomline: use a real TIMESTAMP field!
Note that Firebird supports multiple formats:
yyyy-mm-dd, eg 2014-05-25 (ISO-8601 format, probably best to use as it reduces confusion)
dd.mm.yyyy, eg 25.05.2014
mm/dd/yyyy, eg 05/25/2014
mm-dd-yyyy, eg 05-25-2014
dd mmm yyyy, eg 25 MAY 2014 (+ variations with a -, . or / as separator)
mmm dd yyyy, eg MAY 25 2014 (+ variations with a -, . or / as separator)
select DATE from TABLE where cast(DATE as date) = '30.12.2011'
Date field is a timestamp
Here is the answere to my question:
CAST
(
SUBSTRING
(field FROM 1 FOR 2)
||'.'||
SUBSTRING
(field FROM 4 FOR 2)
||'.'||
SUBSTRING
(field FFROM 7 FOR 4)
AS DATE)
This took me 5 hours to find this out, maybe there should be a "-" instead of "." but it works.
I have a table student with the following columns:
no - integer
name - string
startdate - date
enddate - date.
Date format is MM/DD/YYYY.
I will give a date as input. Now I need a query the inputdate which found in between the start and end date.
For an example I will give 04/14/2012, then the query should return the 1st record as in the figure.
(because input date (04/14/2012) is found in between the 04/10/2012 to 04/20/2012)
Please help me.
The issue you are having is caused by your assumption that sqlite has a date/datetime type when in fact it doesn't.
I suggest you read the following http://www.sqlite.org/datatype3.html to have a better understanding of sqlite types.
The dates in the MM/DD/YYYY format are handled as TEXT by sqlite, and so those dates are compared as strings. For example, 02/01/2012 is considered bigger than 01/02/2012by sqlite if compared directly.
You will need to transform those dates to a format that can be string-compared. Here is an example:
sqlite> create table foo (d TEXT);
sqlite> insert into foo values ('02/01/2012');
sqlite> select substr(d, 7, 4) || substr(d, 1, 2) || substr(d, 4, 2) from foo;
20120201
You should post what you have tried so far.
There should be a between clause that you can use:
select * from table
where inputdate between startdate and enddate
Dates as a date type in SQLite don't exist. There are a number of approaches to dealing with dates - store them as integer seconds since 1 Jan 1970 (unixepoch) or store them as strings, but if you do, then you really need to store them in 'YYYY-MM-DD' format because that is what the date functions require as input.
Assuming you use the string format in the format I suggested then your query would look something like
SELECT * FROM Table WHERE Date(Inputdate) BETWEEEN Date(startDate) AND Date(EndDate);
(although you may want to format the output of the date columns to US date format with
SELECT Strftime("%m/%d/%Y",startDate) As StartDate ...
If you use seconds since 1970 its somewhat easier because the seconds just compare without needing the convert them to dates, although you still might want to output in US date format, so ...
SELECT Strftime("%m/%d/%Y",startDate) As StartDate ... FROM Table WHERE inputDate BETWEEN startDate and EndDate;
sqlite> select *from tbl_node where mydate between '2014-02-02' and '2014-02-06';
it show the output :-
1|1|123|456|12eb-ab|1|1|254|123|19|2014-02-03 16:00:44
2|1|123|456|12eb-ab|1|1|254|123|19|2014-02-03 16:01:03
3|1|123|456|12eb-ab|1|1|254|123|19|2014-02-03 16:00:57
4|1|123|456|12eb-ab|1|1|254|123|19|2014-02-03 16:00:34
Here mydate is column name in tbl_node;
we can also use from current time , using now.
sqlite> select *from tbl_node where mydate between '2014-02-02' and 'now';