What is CHAR(7) in Teradata SQL in date format? - sql

I am trying to get the idea of char(7) in the following SQL in Teradata:
SELECT current_date (FORMAT'YYYY-MM') (char(7));
as far as it forces the display of the correct format, exactly as specified.
When I try without char(7) at the end, the format is not as specified, e.g.:
SELECT current_date (FORMAT 'YYYY-MM');
returns the day as well, ignoring the format command:
As a subquestion - is this the correct way to display the month and the year from a date column? (with char(7))

I would suggest using TO_CHAR here:
SELECT TO_CHAR(CURRENT_DATE, 'YYYY-MM');
This takes the guesswork out of your problem, as the contract of TO_CHAR is to return a string representation of the input datetime using the format mask you specify. You do not need to worry about requesting a certain string width.

Related

count records in specific date format with SQL

i'm trying to define a rule that count rows where date format is dd/mm/yyyy and greater than a specific date in sql but i couldn't find the right function to use.
The second part is working : SELECT COUNT (*) FROM CUSTOMER WHERE DAT_0 >= '01/01/1995' but how could i specify the format too
In Standard SQL, the WHERE clause would look like:
WHERE DAT_0 >= DATE '1995-01-01'
Many databases would simply accept this without the DATE as well:
WHERE DAT_0 >= '1995-01-01'
In your comment DATE_0 is a date column
Therefore we can change it to any format as below using to_char then to_date
to_date(to_char(DATE_0,'yyyymmdd'),'yyyy-mm-dd')
When comparing you can try this, converting the date to_number, i find it very easy
to_number(to_char(DATE_0,'yyyymmdd')) > 19950101
if datatype of "DAT_0" is date or datetime or timestamp , they are recorded as a specific format specified by default datetime setting in your database engine , therefore you can't have multiple format inside the column , so there is no concern there

Oracle SQL - convert a varchar2 into a date

I have a problem with converting a varchar2 fields into a date format.
I got 2 columns with the datatyp varchar2, one is called qtime the other is called ztime. Both fields contain strings in this format (f.e. 152015 -> would be a timestamp 15:20:15).
For reporting reasons I need to convert this fields into a date format, afterwards I want to substract (qtime-ztime) the fields an convert them into the format [hh] (f.e. after the operation 01:20:00 would be -> 01). Is it possible to to this within Oracle SQL 12c? The biggest problem for me right now is that I don't get those Strings converted into a date format.
select TO_DATE(qtime,'MM/DD/YYYY hh24:mi:ss') just gives me
ORA-01861:"literal does not match format string"
select TO_DATE(qtime,'hh24mmss') gives me a wrong Date
01.03.2018
select TO_TIMESTAMP(qtime,'hh24mmss') gives me a wrong Date
01.03.2018 BUT the correct time with f.e. 15:20:15,0000000
Thank you in advance, any help is appreciated
Note: I only have reading rights on the database Oracle 12c, so I need to to this within Statements
"The Database contains another column with the correct date for each time"
The missing piece of the puzzle! Concatenate the two columns to get something which can be converted to an Oracle DATE:
select to_date(qdate||qtime, 'yyyymmddhh24miss') as qdatetime
, to_date(zdate||ztime, 'yyyymmddhh24miss') as zdatetime
from your_table
Once you have done that you can perform arithmetic of the dates e.g.
select id
, zdatetime - qdatetime as time_diff
from ( select id
, to_date(qdate||qtime, 'yyyymmddhh24miss') as qdatetime
, to_date(zdate||ztime, 'yyyymmddhh24miss') as zdatetime
from your_table
)
If you want the number of hours in the difference you can include this expression in the projection of the outer query:
, extract( hour from (zdatetime - qdatetime) day to second) as hrs_ela
First off, if you are trying to convert a varchar2 into a date without specifying neither day nor month, it will default to the first day of the current month:
If you specify a date value without a date, then the default date is the first day of the current month.
You can read up more here
Also in 2nd and 3rd your example, you are using 'hh24mmss' for specifying hour, minute and second components, but do note that correct format for minutes is 'mi' and not 'mm', which is used for months.
So the solution is to concatenate both date and time component when creating the date as the other answer suggested, tho I would recommend using a single date field as it can store the information you need.

DB2 Convert Number to Date

For some reason (I have no control over this) dates are stored as Integers in an iSeries AS400 DB2 system that I need to query. E.g. today will be stored as:
20,171,221
Being in the UK I need it to be like the below in Date format:
21/12/2017
This is from my query: (OAORDT = date field)
Select
Date(SUBSTR( CHAR( OAORDT ),7,2) ||'/' || SUBSTR(CHAR ( OAORDT ),5,2) || '/' || SUBSTR(CHAR (OAORDT ),1,4)) AS "Order Date"
from some.table
However, all I get is Nulls. If I remove the Date function, then it does work but its now a string, which I don't want:
Select
SUBSTR( CHAR( OAORDT ),7,2) ||'/' || SUBSTR(CHAR ( OAORDT ),5,2) || '/' || SUBSTR(CHAR (OAORDT ),1,4) AS "Order Date"
from some.table
How do I convert the OAORDT field to Date?
Just to update - I will be querying this from MS SQL Server using an OpenQuery
Thanks.
1) How do I convert the OAORDT field to Date?
Simplest is to use TIMESTAMP_FORMAT :
SELECT DATE(TIMESTAMP_FORMAT(CHAR(OAORDT),'YYYYMMDD'))
2) Being in the UK I need it to be [...] in Date format 21/12/2017 :
SELECT VARCHAR_FORMAT(DATE(TIMESTAMP_FORMAT(CHAR(OAORDT),'YYYYMMDD')),'DD/MM/YYYY')
Note, you didn't specify where you are doing this, but since you tagged as ibm-midrange, I am answering for embedded SQL. If you want JDBC, or ODBC, or interactive SQL, the concept is similar, just the means of achieving it is different.
Make sure SQL is using dates in the correct format, it defaults to *ISO. For you it should be *EUR. In RPG, you can do it this way:
exec sql set option *datfmt = *EUR;
Make sure that set option is the first SQL statement in your program, I generally put it immediately between D and C specs.
Note that this is not an optimal solution for a program. Best practice is to set the RPG and SQL date formats both to *ISO. I like to do that explicitly. RPG date format is set by
ctl-opt DatFmt(*ISO);
SQL date format is set by
exec sql set option *datfmt = *ISO;
Now all internal dates are processed in *ISO format, and have no year range limitation (year can be 0001 - 9999). And you can display or print in any format you please. Likewise, you can receive input in any format you please.
Edit Dates are a unique beast. Not every language, nor OS knows how to handle them. If you are looking for a Date value, the only format you need to specify is the format of the string you are converting to a Date. You don't need to (can't) specify the internal format of the Date field, and the external format of a Date field can be mostly anything you want, and different each time you use it. So when you use TIMESTAMP_FORMAT() as #Stavr00 mentioned:
DATE(TIMESTAMP_FORMAT(CHAR(OAORDT),'YYYYMMDD'))
The format provided is not the format of the Date field, but the format of the data being converted to a Timestamp. Then the Date() function converts the Timestamp value into a Date value. At this point format doesn't matter because regardless of which external format you have specified by *DATFMT, the timestamp is in the internal timestamp format, and the date value is in the internal date format. The next time the format matters is when you present the Date value to a user as a string or number. At that point the format can be set to *ISO, *EUR, *USA, *JIS, *YMD, *MDY, *DMY, or *JUL, and in some cases *LONGJUL and the *Cxxx formats are available.
Since none of variants suited my needs I've came out with my own.
It is as simple as:
select * from yourschema.yourtable where yourdate = int(CURRENT DATE - 1 days) - 19000000;
This days thing is leap year-aware and suits most needs fine.
Same way days can be turned to months or years.
No need for heavy artillery like VARCHAR_FORMAT/TIMESTAMP_FORMAT.
Below worked for me:
select date(substring(trim(DateCharCol), 1, 2)||'/'||substring(trim(DateCharCol), 3, 2)||'/'||'20'||substring(trim(DateCharCol), 5, 2)) from yourTable where TableCol =?;

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