How to convert this string into timestamp in postgresql? - sql

I want to convert a string into timestamp
I am using the following command for it
SELECT To_timestamp ('12-31-2021-23-38-02', 'DD-MM-YYYY-HH24-MI-SS');
However it is returning me '2023-07-17 23:38:02' this instead of '2021-31-12 23:38:02'

Place of month & day in the input string doesn't match format string.
Use:
SELECT To_timestamp ('12-31-2021-23-38-02', 'MM-DD-YYYY-HH24-MI-SS');
As pointed out in the comments, it's apparent that you're using Postgres prior to version 10.
Since Postgres 10, your query throws below error:
ERROR: date/time field value out of range: "12-31-2021-23-38-02"
dbfiddle.uk - Postgres 10

Related

Convert string of YYYYMMDD to YYYY-MM-DD Date format in Snowflake

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')

Presto/SQL - Converting string timestamp to date throws error

NOTE: I am running my query in Qubole's presto and sql command engine.
I am trying to convert my string timestamp to just date but none of the options are working out.
My string timestamp looks like 2017-03-29 10:32:28.0
and I want to have it like 2017-03-29
I have tried following queries to convert this string timestamp to retrieve date
1. select cast(created as date) from table1
Value cannot be cast to date: 2017-05-26 17:23:58.0
2. select cast(from_iso8601_timestamp(created) as date) from table1
Invalid format: "2014-12-19 06:06:36.0" is malformed at " 06:06:36.0"
3. select date(created) from table1
Value cannot be cast to date: 2012-10-24 13:50:00.0
How I can convert this timestamp to date in presto/sql?
As far as explained in the documentation, prestoDB seems to expect timestamps in a format '2001-08-22 03:04:05.321', and dates in a '2001-08-22'.
One solution would be to use a string function to extract the relevant part of the string before converting it. We know that the date part is located before the first space in the string, so.
If you need the date part as a string datatype:
split_part(created, ' ', 1)
If you need the date part as a date datatype:
cast(split_part(created, ' ', 1) as date)
You can try to use one of the following solutions:
SELECT
'2017-03-29 10:32:28.0' AS input_string,
DATE(date_parse('2017-03-29 10:32:28.0', '%Y-%m%-%d %H:%i:%s.%f')) AS solution_1,
DATE(try_cast('2017-03-29 10:32:28.0' as timestamp)) AS solution_2

NULL values in a string to date conversion

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

How to change date format in hive?

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.

How can I convert a varchar field (YYYYMM) to a date (MM/01/YY) in SQL?

I'm sure this is quite simple, but I've been stuck on it for some time. How can I convert a varchar field (YYYYMM) to a date (MM/01/YY) in SQL?
Thanks.
Edit: I'm using Open Office Base (HSQL), not MySQL; sorry for the confusion.
Try the str_to_date and date_format functions. Something like:
select date_format( str_to_date( my_column, '%Y%c' ), '%c/01/%y' ) from my_table
try :
SELECT STR_TO_DATE(CONCAT(myDate,'01'),'%Y%m%d')
FROM myTable
Use STR_TO_DATE:
From mysql.com:
STR_TO_DATE(str,format)
This is the inverse of the DATE_FORMAT() function. It takes a string str and a format string format. STR_TO_DATE() returns a DATETIME value if the format string contains both date and time parts, or a DATE or TIME value if the string contains only date or time parts.
The date, time, or datetime values contained in str should be given in the format indicated by format. For the specifiers that can be used in format, see the DATE_FORMAT() function description. If str contains an illegal date, time, or datetime value, STR_TO_DATE() returns NULL. Starting from MySQL 5.0.3, an illegal value also produces a warning.
Range checking on the parts of date values is as described in Section 11.3.1, “The DATETIME, DATE, and TIMESTAMP Types”. This means, for example, that “zero” dates or dates with part values of 0 are allowed unless the SQL mode is set to disallow such values.
mysql> SELECT STR_TO_DATE('00/00/0000', '%m/%d/%Y');
-> '0000-00-00'
mysql> SELECT STR_TO_DATE('04/31/2004', '%m/%d/%Y');
-> '2004-04-31'
Get the year:
SUBSTRING(field FROM 2 FOR 2)
Get the month:
SUBSTRING(field FROM -2 FOR 2)
Compose the date:
CONCAT(SUBSTRING(field FROM -2 FOR 2), '/01/', SUBSTRING(field FROM 2 FOR 2))
This will convert from YYYYMM to MM/01/YY.
To be clear: if you're looking for method to convert some value of type Varchar/Text to value of type Date than solutions are:
using CAST function
CAST(LEFT('201205',4)||'-'||SUBSTRING('201205' FROM 5 FOR 6)||'-01' AS DATE)
starting from OpenOffice 3.4 (HSQLDB 2.x) new Oracle-like function TO_DATE supposed to be available
TO_DATE('201205','YYYYMM')
in addition to the written i can mention that you also can construct a string with ANSI/ISO 'YYYY-MM-DD' formatted representation of the date,- Base will acknowledge that and succesfully convert it to the Date type if necessary (e.g. INSERTing in Date typed column etc.)
Here is doc's on HyperSQL and highly recommended OO Base guide by Andrew Pitonyak