I have date string column in my dataset and this date string column has date values in the formats as shown below
Some dates are in the format : 2020-04-22 and
some dates are in the format : 04/22/2020
Kindly suggest how to parse these date values to a timestamp format : 2020-04-22 00:00:00 UTC
Thanks!
You need to normalise both dates.
Try using:
SELECT
COALESCE(SAFE.PARSE_DATE('%F', your_date_field), SAFE.PARSE_DATE('%m/%d/%Y', your_date_field)) AS your_new_date_field
FROM ...
If all strings strictly conform to one format or the other, you can do conditional logic:
PARSE_TIMESTAMP(
CASE
WHEN REGEXP_CONTAINS(mydate, r"^\d{4}-\d{2}-\d{2}$" THEN "%F"
WHEN REGEXP_CONTAINS(mydate, r"^\d{2}/\d{2}/\d{4}$" THEN "%m/%d/%Y"
END,
mydate
)
You might want to use SAFE.PARSE_TIMESTAMP() instead of PARSE_TIMESTAMP() to prevent conversion failures on unmatched formats.
Related
I have dates in the format '6/30/2020'. It is a string and I want to convert it into date format.
List of methods I have tried
Cast('6/30/2020' as date) #returns null
to_date('6/30/2020','yyyy/MM/dd') #returns null
I also tried splitting the string and then concatenating it into data.
After trying all this and putting all the possible combinations in the to_date function, I am still getting the answer as null.
Now I am confused as I have used all the functions to convert string to date.
Thanks in advance for your help.
The date format you used was incorrect. Try this:
select to_date('6/30/2020', 'M/dd/yyyy')
If you want to format your result, you can use date_format:
select date_format(to_date('6/30/2020', 'M/dd/yyyy'), 'yyyy/MM/dd')
Note that to_date converts a given string from the given format, while date_format converts a given date to the given format.
Based on the example mentioned here in the Snowflake documentation, why are the date and timestamp values returning different values just by changing the ORDER BY clause? Also, I am trying to convert a string to a date format which is not returning correct results in Snowflake while this works fine in other SQL based Engines. Need help from experts on this.
This query
SELECT '20200710', TO_DATE('20200710');
is returning the following output
20200710 | 1970-08-22
Also tried:
SELECT TO_DATE('20200710', 'YYYY-MM-DD');
and got the error:
Can't parse '20200710' as date with format 'YYYY-MM-DD'
To convert to a date data type, you would use:
SELECT TO_DATE('20200710', 'YYYYMMDD')
I would recommend just keeping the date data type. But if you want a string in the format YYYY-MM-DD:
SELECT TO_CHAR(TO_DATE('20200710', 'YYYYMMDD'), 'YYYY-MM-DD')
I have a table with the following data:
logs.ip logs.fecha logs.metodo
66.249.93.79 19/Nov/2018:03:46:33 GET
All data columns are string and I want to convert logs.fecha into date with the following format: YYYY-MM-dd HH:mm:ss
I try the following query:
SELECT TO_DATE(from_unixtime(UNIX_TIMESTAMP(fecha, 'yyyy-MM-dd'))) FROM logs
Results of the query are NULL in all rows.
How can I make the conversion string to date for all rows? I know I must use ALTER TABLE but I don't know how to do it.
Thanks
The reason you get null is because the format of the input string is different from the input passed to unix_timestamp. The second argument to unix_timestamp should specify the string format of the first argument. In from_unixtime you can specify the output format desired. If nothing is specified, a valid input to from_unixtime returns an output in yyyy-MM-dd format.
The error can be fixed as below.
from_unixtime(unix_timestamp(fecha,'dd/MMM/yyyy:HH:mm:ss'),'yyyy-MM-dd HH:mm:ss')
You just have to tell Oracle the date format you are reading with TO_DATE.
Try:
SELECT TO_DATE(fecha,'DD/MON/YYYY:HH:MI:SS') FROM logs
My table in hive has a filed of date in the format of '2016/06/01'. but i find that it is not in harmory with the format of '2016-06-01'.
They can not compare for instance.
Both of them are string .
So I want to know how to make them in harmory and can compare them. Or on the other hand, how to change the '2016/06/01' to '2016-06-01' so that them can compare.
Many thanks.
To convert date string from one format to another you have to use two date function of hive
unix_timestamp(string date, string pattern) convert time string
with given pattern to unix time stamp (in seconds), return 0 if
fail.
from_unixtime(bigint unixtime[, string format]) converts the
number of seconds from unix epoch (1970-01-01 00:00:00 UTC) to a
string representing the timestamp of that moment in the current
system time zone.
Using above two function you can achieve your desired result.
The sample input and output can be seen from below image:
The final query is
select from_unixtime(unix_timestamp('2016/06/01','yyyy/MM/dd'),'yyyy-MM-dd') from table1;
where table1 is the table name present in my hive database.
I hope this help you!!!
Let's say you have a column 'birth_day' in your table which is in your format,
you should use the following query to convert birth_day into the required format.
date_Format(birth_day, 'yyyy-MM-dd')
You can use it in a query in the following way
select * from yourtable
where
date_Format(birth_day, 'yyyy-MM-dd') = '2019-04-16';
Use :
unix_timestamp(DATE_COLUMN, string pattern)
The above command would help convert the date to unix timestamp format which you may format as you want using the Simple Date Function.
Date Function
cast(to_date(from_unixtime(unix_timestamp(yourdate , 'MM-dd-yyyy'))) as date)
here is my solution (for string to real Date type):
select to_date(replace('2000/01/01', '/', '-')) as dt ;
ps:to_date() returns Date type, this feature needs Hive 2.1+; before 2.1, it returns String.
ps2: hive to_date() function or date_format() function , or even cast() function, cannot regonise the 'yyyy/MM/dd' or 'yyyymmdd' format, which I think is so sad, and make me a little crazy.
I have Following dummy table with data:
ACID srno date(mm/dd/yyyy) name
3 1 04/12/2010 mahesh
3 2 04/12/2010 mahendra
Now if I try with Following SQL Transact:
select srno from dummy
where name = 'mahesh'
and date= convert(datetime,'12/04/2010',101) –- I have date in dd/MM/yyyy Format
and ACID=3
It’s Not returning the srno of the table. That means Date is not execute convert statement as above
What’s the reason?
Try using style 103 instead of 101.
select srno from dummy
where name = 'mahesh'
and date= convert(datetime,'12/04/2010',103) –- I have date in dd/MM/yyyy Format
and ACID=3
If you convert 12/04/2010 using format 101, you get date "December 4, 2010", which is not in your database. Use format 103 to convert a date in format dd/mm/yyyy to DateTime.
The database stores dates using the DateTime type which is format-agnostic. It does have a default format for string conversions, which seems to be mm/dd/yyyy (101) on your database.
However, when you convert a string to add it to your table, you want to specify the format of your input string, in your example dd/mm/yyyy (103).
Take a look at the MSDN article for CAST and CONVERT which details all format styles that you can use with dates.
To be honest, if you want to specify a DATE LITERAL in SQL Server, please stick with the simplest YYYYMMDD format, e.g.
and dummy.date = '20100412'
It is robust and works for all regional, user language and dateformat settings. This assumes the other side of the comparison is already a date column. Even if you had to CAST it, using this format you don't need to specify a format
and dummy.date = cast('20100412' as datetime)