Formatting date sql - sql

I want to format existing dates in a column called mydate in a table called empl. However, I am going no where with this. I have tried
SELECT CONVERT(VARCHAR(10), mydate,103) from empl
but get a missing expression error.
I want to change the current format in the column which is in the format
dd-mm-yy to mm/dd/yy
EDIT: im using oracle
Any suggestions?

If the datatype of the column is DATE, you can use the TO_CHAR() function:
SELECT to_char(mydate, 'mm/dd/yy')
FROM empl ;

Are you able to change the column type to date? Then you could use date_format

The Convert statement you show is for MS-SQL, and you would want code 3 not 103, the 100 series give 4 digit years.
Try:
select to_char(mydate,'MM/DD/YY') from empl

Assuming mydate is stored in date datatype, and using oracle, easy way to do that is:
select to_char(mydate, 'dd/mm/yy') from empl
In Oracle, convert is used to change character set with parameters
(char, destination_char_set, source_char_set)

select TO_CHAR(sysdate, 'MM/DD/YYYY') CHRDATE from dual;

Related

[SQL]Removing day in yyyy/mm/dd datetime format in sql

I'm using PostgreSQL, but this question is for any modern dbms
I want to basically convert a datetime column which has yyyy/mm/dd into just yyyy/mm
I tried getting months and year separately and using Concat, but the problem is the month comes as a single digit integers for values < 10 and that messes up ordering
select *,
concat(date_part('year' , date_old), '/', date_part('month' , date_old)) as date_new
from table
date _old
date_new
2010-01-20
2010-1
2010-01-22
2010-1
2010-11-22
2010-11
You can use to_char()
to_char(date_old, 'yyyy/mm')
If you want to display your date in the format YYYY-MM then
In PostgreSQL (db<>fiddle) and Oracle (db<>fiddle), use TO_CHAR:
SELECT TO_CHAR(date_old, 'YYYY/MM') FROM table_name;
In MySQL (db<>fiddle), use DATE_FORMAT:
SELECT DATE_FORMAT(date_old, '%Y/%m') FROM table_name;
In SQL Server (db<>fiddle), use CONVERT or, if you are using SQL Server 12 or later, FORMAT:
SELECT CONVERT(varchar(7), date_old, 111) FROM table_name;
SELECT FORMAT(date_old,'yyyy/MM') FROM table_name;
Don't do this.
If you're able to use the date_part() function, what you have is not actually formatted as the yyyy/mm/dd value you say it is. Instead, it's a binary value that's not human-readable, and what you see is a convenience shown you by your tooling.
You should leave this binary value in place!
If you convert to yyyy/mm, you will lose the ability to directly call functions like date_part(), and you will lose the ability to index the column properly.
What you'll have left is a varchar column that only pretends to be a date value. Schemas that do this are considered BROKEN.

Convert Number type to Date in postgres SQL

I have a numeric data in a column 20170930, need help in converting it into Date in PostgreSQL , tried multiple ways but non seems to work
You can convert to a string and then to a date:
select column::text::date
You can also express this using explicit cast() syntax:
select cast(cast(20170930 as text) as date)
Use one of the following :
SELECT cast(yourcol::varchar as date ) as dt1, yourcol::varchar::date as dt2
where dt1 and dt2 values of type date, and yourcol is a numeric value such as 20170930
Demo
The best thing is to change column datatype into Date type,
ALTER TABLE table_name
ADD column_name Date;
As shown above, PostgreSQL supports a full set of SQL date and time types, as shown in the table below. Dates are counted according to the Gregorian calendar. Here, all the types have a resolution of 1 microsecond / 14 digits except date type, whose resolution is day.
Please try below query
SELECT to_date(column::varchar,'YYYYMMDD')
For anybody who fell into my pitfall I tried this but my numeric was like a 'seconds past 01-01-1970 format' rather than YYYYMMDD
This worked
SELECT to_timestamp(yourcol) as numeric_column_now_date
from yourtable
see here
https://www.postgresql.org/docs/current/functions-datetime.html#FUNCTIONS-DATETIME-ZONECONVERT

Convert date to month year format and pass it in the query

I have a BIRT report where user will be entering the dates in dd-mm-yyyy format however I need to convert dd-mm-yyyy to MON-YYYY format.
I have tried to use VARCHAR_FORMAT(FIELDNAME,'MON-YYYY') however it doesn't work.
select …….
where VARCHAR_FORMAT(fieldname,'MON-YYYY') = '2017-05-15';
User would end the date as
15/05/2017
The value present in the database for this field is 2017-05-15 07:30:00.0
update
Apparently the column is not a string but a datetime which means the conversion is only
to_date(fieldname, 'MON-YYYY')
But if the column is used in a Where clause it shouldn’t be converted at all.
——
Use to_date and to_char to first convert your string to a date and then back to a string with the right format
to_char(to_date(fieldname, 'DD-MM-YYYY'), 'MON-YYYY')
select *
from table (values
timestamp('2017-05-15-07.30.00')
) t(fieldname)
where
fieldname between to_date('15/05/2017', 'DD/MM/YYYY') and to_date('15/05/2017', 'DD/MM/YYYY') + 1 day
--date(fieldname) = to_date('15/05/2017', 'DD/MM/YYYY')
;
You may run it as is.
Both cases work, but to use the 2-nd one efficiently, you must create an index by the date(fieldname) expression (since db2 10.5) or add generated always column to the table with the same expression and index on it.

How do I convert this oracle date

I am trying to convert from one date format to another. I am not sure how to write the functions.
My source date looks like 01/15/2009 01:23:15
The format I need is 01152009.
Thanks
Try this.
TO_CHAR(TO_DATE('01/15/2009 01:23:15','MM/DD/YYYY HH:MI:SS'),'MMDDYYY')
More info here,
http://psoug.org/reference/date_func.html
Does this work for you? It assumes the date is in date format but will work with timestamp
select to_char(YourDateField,'DDMMYYYY') from dual;
You can always convert it back to a date using the TO_DATE function if you need that format.
select TO_CHAR(TO_DATE('01/15/2009 01:23:15','MM/DD/YYYY MI:HH:SS'),'MMDDYYYY') from dual
if your field is already of data type date then you should only do:
select TO_CHAR(<fieldname>,'ddmmyyyy') ...

Comparing date with sysdate in oracle

I have a column which is of "DATE" type and I want to run a query on it comparing it with sysdate.
But I am getting following error, Can someone please let me know what I am missing here?
SQL> select distinct file_name as r
from table_1
where view_day >= TO_DATE(SYSDATE-10, 'YYYY/MM/DD');
ERROR at line 1:
ORA-01858: a non-numeric character was found where a numeric was expected
You shouldn't use to_date on a date, To_date is for casting a varchar to date, not a date.
If you do use the function to_date on a date, then oracle will refer to it as a string according to nls_date_format which may vary in different environments.
As #jonearles said, if you want to remove the time in sysdate then use TRUNC
USE:
select distinct file_name as r
from table_1
where view_day >= TRUNC(SYSDATE-10)
Error shows that a VIEW_DAY column is varchar so you need to convert DATE to String. Use TO_CHAR or convert VIEW_DAY to date type.