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.
Related
this is my table:
table name EXAMPLE
column name DATE
this is the output for the following query:
SELECT date
FROM example;
1/23/2010
I want to convert the output to:
23-Jan-10
Is it possible?
Thanks
You can use formatting along with TO_CHAR() conversion such as
SELECT TO_CHAR(dt,'DD-Mon-RR')
FROM example
where
DATE is not a good name for a column as being a reserved keyword. So, I've replaced it with dt
If your column is in varchar/text.. then you can first convert to date then back to char
SELECT
TO_CHAR(
to_date('1/23/2010','mm/dd/yyyy'),'DD-Mon-YY'
)
datec FROM dual;
If it is in date format, to_char only will do
SELECT
TO_CHAR(date_column, 'DD-Mon-YY' )
datec FROM dual;
A DATE data type is a binary format that is stored in 7-bytes that has no format and always contains the components: year (stored as century and year-of-century), month, day, hour, minute and second.
Therefore, you cannot change the format of a DATE data type.
If instead, you ask the question:
How can format a DATE to output it as 23-Jan-10?
Then you can convert the DATE to a formatted string using the TO_CHAR function:
SELECT TO_CHAR(your_date_column, 'DD-MON-YY', 'NLS_DATE_LANGUAGE=English')
AS formatted_date
FROM your_table;
Alternatively, if you want the output as a DATE data type then you can use:
SELECT your_date_column
FROM your_table;
and change the user interface (SQL/Plus, SQL Developer, Toad, PLSQLDeveloper, PHP, Java, etc.) you are using to alter how that that user interface displays dates. The solution is going to depend on which user interface you are using but for SQL/Plus and SQL Developer, you can change Oracle's NLS_DATE_FORMAT session parameter:
ALTER SESSION SET NLS_DATE_FORMAT = 'DD-MON-YY';
Other user interfaces will have different solutions specific to those interfaces.
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
I am a newbie for Oracle database programming and I wish to INSERT date (also display) in 'DD MON YYYY' format. (PS: This only involves INSERT event). Which data type (DATE or TIMESTAMP) is the most suitable option for me in order to accomplish this format? How was I supposed to do that? Thanks.
A DATE column does not have any format.
So the format that you use when inserting or updating data is irrelevant for displaying that data (that's one of the reasons why you should never store a date in a VARCHAR column).
Any formatted output you see for a DATE column in your SQL tool (e.g. SQL*Plus) is applied by that tool. It is not part of the data stored in that column.
When providing a date literal you should either use the to_date() function with an explicit format mask:
insert into some_table (some_date_column)
values (to_date('27-06-2014', 'dd-mm-yyyy'));
I also do not recommend using formats with written month names (27-JUN-2014) when supplying a date literal because they also depend on the NLS settings of the client computer and might produce (random) errors due to different languages. Using numbers only is much more robust.
I prefer to use ANSI date literals because it's a bit less typing:
insert into some_table (some_date_column)
values (DATE '2014-06-27');
The format for an ANSI date (or timestamp) literal is always the ISO format (yyyy-mm-dd).
When you select your data you can display the date in whatever format you like. Either by using the to_char() function (e.g. when using a SQL tool) or using functions from your programming language (the preferred way to use inside an application):
select to_char(some_date_column,'dd-mon-yyyy')
from some_table;
Note that the DATE data type in Oracle (despite it's name) also stores the time. a TIMESTAMP does the same thing only with a higher precision (it includes milliseconds, whereas the DATE data type only stores seconds).
To insert a record,
INSERT INTO TABLE_NAME (DATE_FIELD) VALUES (TO_DATE ('27-JUN-2014', 'DD-MON-YYYY');
It is advisable to use DATE data-type until and unless you need the date's accuracy to be till milli seconds. In your case, go with DATE datatype and TIMESTAMP is not necessary
To select a record,
SELECT TO_CHAR(DATE_FIELD, 'DD-MON-YYYY') FROM TABLE_NAME;
In genral, remember this:
TO_DATE is a function used to convert a string(CHAR) TO DATE
TO_CHAR is a function used to convert a DATE to a string(CHAR)
In this scenario date datatype will be suitable for you, and for the desired format you should try like this:-
INSERT INTO TABLE_NAME(DATE_COLUMN) VALUES('27-JUN-2014');
Hope this can help you.
Thanks for your help. I am not able to make out the type/format of the "Value" in a Date column.I guess its in Julian Date format.
The Column is paid_month and the values are below.
200901
200902
So,please help in writing SQL query to convert the above values(Mostly in Julian Format) in the Date Column to normal date (MM/DD/YYYY) .
Thanks
Rohit
Hi,
I am sorry for missing in giving the whole information.
1)Its a Oracle Database.
2)The column given is Paid_Month with values 200901,200902
3)I am also confused that the above value gives month & year.Day isnt given if my guess is right.
4)If its not in Julian format ,then also please help me the SQL to get at least mm/yyyy
I am using a Oracle DB and running the query
THANKS i GOT THE ANSWER.
**Now,i have to do the reverse meaning converting a date 01/09/2010 to a String which has 6 digits.
Pls help with syntax-
select to_char(01/01/2010,**
It looks like YYYYMM - depending on your database variant, try STR_TO_DATE(paid_month, 'YYYYMM'), then format that.
Note: MM/DD/YYYY is not "normal" format - only Americans use it. The rest of the world uses DD/MM/YYYY
For MySQL check
http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html#function_date-format
Example:
SELECT DATE_FORMAT(NOW(), '%d/%m/%Y')
For MySQL, you would use the STR_TO_DATE function, see http://dev.mysql.com/doc/refman/5.0/en/date-and-time-functions.html#function_str-to-date
SELECT STR_TO_DATE(paid_month,'%Y%m');
Sounds like the column contains some normal dates and some YYYYMM dates. If the goal is to update the entire column, you can attempt to isolate the YYYYMM dates and update only those. Something like:
UPDATE YourTable
SET paid_month = DATE_FORMAT(STR_TO_DATE(paid_month, '%Y%m'), '%m/%d/%Y')
WHERE LENGTH(paid_month) = 6
SELECT (paid_month % 100) + "/01/" + (paid_month/100) AS paid_day
FROM tbl;
I'm not sure about how oracle concatenates strings. Often, you see || in SQL:
SELECT foo || bar FROM ...
or functions:
SELECT cat (foo, bar) FROM ...
Is there a way to convert a date to a string in Sqlite? For example I am trying to get the min date in Sqlite:
SELECT MIN(StartDate) AS MinDate FROM TableName
I know in SQL Server I would use the SQL below to accomplish what I am trying to do:
SELECT CONVERT(VARCHAR(10), MIN(StartDate), 101) AS MinDate FROM TableName
Thanks!
SQLite doesn't have a date type. What CURRENT_TIMESTAMP actually returns is a string in the format YYYY-MM-DD HH:MM:SS. The date/time formatting/calculation functions accept strings in this format, or alternatively, numbers, which are interpreted as Julian dates unless you use the 'unixepoch' modifier.
So, "converting a date to a string" depends on how you're storing your dates:
If you're storing them as Julian dates, use DATE(YourDateColumn).
If you're storing them as Unix times, use DATE(YourDateColumn, 'unixepoch').
If you're storing them as ISO 8601 strings, then, well you don't have to do anything. Unless you want a string in a different format, in which case you should use the STRFTIME function.
If you're storing them as some other string format, you really should consider using one of the supported formats so you can use the date/time functions.
In all three date formats, chronological order is the same as lexicographical order, so the MIN function works as expected.
try this!!
SELECT * FROM Table WHERE strftime('%Y-%m-%d',CreatedAt) BETWEEN '2014-10-07' AND '2014-10-17'
Try this:
SELECT MIN(DATE('your-date-here')) as MinDate FROM TableName
And make sure your-date-here follows a well understood format by SQLite (See the Time String. section in the documentation)