storing date in 'CCYYMMDD' format in Teradata - sql

I would like to store dates in the format CCYYMMDD in Teradata, but I fail to do so. Find below what I tried so far:
query 1:
SEL CAST(CAST(CURRENT_DATE AS DATE FORMAT 'YYYYMMDD') AS VARCHAR(8))
-- Output: 20191230 ==> this works!
query 2:
SEL CAST(CAST(CURRENT_DATE AS DATE FORMAT 'CCYYMMDD') AS VARCHAR(8))
-- output: SELECT Failed. [3530] Invalid FORMAT string 'CCYYMMDD'.
It seems that the CCYYMMDD is not available in Teradata right away. Is there a workaround?
Tool used: Teradata SQL assistant

Internally, dates are stored as integers in Teradata. So when you say you want to store them in a different format, I don't think you can do that. But you can choose how to display / return the values.
I'm sure there's a cleaner way to get the format you want, but here's one way:
WITH cte (mydate) AS (
SELECT CAST(CAST(CURRENT_DATE AS DATE FORMAT 'YYYYMMDD') AS CHAR(8)) AS mydate
)
SELECT
CAST(
(CAST(SUBSTRING(mydate FROM 1 FOR 2) AS INTEGER) + 1) -- generate "century" value
AS CHAR(2) -- cast value as string
) || SUBSTRING(mydate FROM 3) AS new_date -- add remaining portion of date string
FROM cte
SQL Fiddle - Postgres
You'd have to add some extra logic to handle years before 1000 and after 9999. I don't have a TD system to test, but give it a try and let me know.

Related

date time stored as varchar in sql how to filter on varchar

I am working on a project in which dates and times ar stored as a varchar e.g. "30-11-2017,7:30" first date in dd-mm-yyy format and then time separated with a comma. I am trying to filter on it but it is not working correctly kindly guide me how to filter data on date.
select *
from timetrack
where startDateAndTime >= '30-11-2017,7:30'
In attached image records have been shown. When I apply above query it shows no records
You can easily convert your date to SQL datatype datetime uisng parse function, for example select parse('30-11-2017,7:30' as datetime using 'it-IT').
So, in your case, you can apply this function in where clause, so you can easily apply comparison between dates:
select *
from timetrack
where parse(startDateAndTime as datetime using 'it-IT') >= '2017-11-30 07:30:00.000'
Your format is apparently italian :) But you have to specify your own date in the format convertable to datetime, as I have done in above example.
NOTE: parse is available starting with SQL Management Studio 2012.
Unless you are using ISO date format (yyyy-MM-dd HH:mm:ss or close) applying ordering (which inequalities like greater than or equal use) will not work: the date order is disconnected from the string ordering.
You'll need to parse the date and times into a real date time type and then compare to that (details of this depend on which RDBMS you are using).
If, you want to just filter out the date then you could use convert() function for SQL Server
select *
from timetrack
where startDateAndTime >= convert(date, left(#date, 10), 103)
Else convert it to datetime as follow
select *
from timetrack
where startDateAndTime >= convert(datetime, left(#date, 10)+' ' +
reverse(left(reverse(#date), charindex(',', reverse(#date))-1)), 103)
You need the date in a datetime column, Otherwise you can't filter with your current varchar format of your date.
Without changing the existing columns, this can be achieved by making a computed column and making it persisted to optimize performance.
ALTER TABLE test add CstartDateTime
as convert(datetime, substring(startDateAndTime, 7,4)+ substring(startDateAndTime, 4,2)
+ left(startDateAndTime, 2) +' '+ right(startDateAndTime, 5), 112) persisted
Note: this require all rows in the column contains a valid date with the current format
Firstly, you need to check what is the data that is entered in the 'startDateAndTime' column,then you can convert that varchar into date format
If the data in 'startDateAndTime' column has data like '30-11-2017,07:30', you would then have to convert it into date:
SELECT to_date('30-11-2017,07:30','dd-mm-yyyy,hh:mm') from dual; --check this
--Your query:
SELECT to_date(startDateAndTime ,'dd-mm-yyyy,hh:mm') from timetrack;

Oracle use LIKE '%' on DATE

My table myTab has the column startDate, which has the datatype "DATE". The data in this column are stored like dd.mm.yyyy.
Now I'm trying to get data with this query:
SELECT * FROM myTab WHERE startDate like '%01.2015"
Somehow it doesn't work and I don't know why.
Hope someone can help.
To make a text search on the date you would have to convert the date to text.
It's more efficient if you calculate the first and last date for what you want to find and get everything between them. That way it's done as numeric comparisons instead of a text pattern match, and it can make use of an index if there is one:
SELECT * FROM myTab WHERE startDate >= DATE '2015-01-01' AND startDate < DATE '2015-02-01'
SELECT * FROM myTab WHERE TO_CHAR(startDate,'dd.mm.yyyy') LIKE '%01.2015'
If the field type is "DATE" then the value isn't stored as a string, it's a number managed by Oracle, so you have to convert it to a string:
SELECT * FROM myTab WHERE to_char(startDate, 'MM.YYYY') = '01.2015';
You can also use date ranges in SQL queries:
SELECT * FROM myTab
WHERE startDate
BETWEEN to_date('01.01.2015', 'DD.MM.YYYY')
AND to_date('31.01.2015', 'DD.MM.YYYY');
Regarding you actual question "Somehow it doesn't work and I don't know why."
Oracle make an implicit conversion from DATE to VARHCAR2, however it uses the default NLS_DATE_FORMAT which is probably different to what you use in your query.
The data in this column are stored like dd.mm.yyyy.
Oracle does not store date in the format you see. It stores it internally in proprietary format in 7 bytes with each byte storing different components of the datetime value.
WHERE startDate like '%01.2015"
You are comparing a DATE with a STRING, which is pointless.
From performance point of view, you should use a date range condition so that if there is any regular INDEX on the date column, it would be used.
SELECT * FROM table_name WHERE date_column BETWEEN DATE '2015-01-01' AND DATE '2015-02-01'
To understand why a Date range condition is better in terms of performance, have a look at my answer here.
I solved my problem that way. Thank you for suggestions for improvements. Example in C#.
string dd, mm, aa, trc, data;
dd = nData.Text.Substring(0, 2);
mm = nData.Text.Substring(3, 2);
aa = nData.Text.Substring(6, 4);
trc = "-";
data = aa + trc + mm + trc + dd;
"Select * From bdPedidos Where Data Like '%" + data + "%'";
To provide a more detailed answer and address this https://stackoverflow.com/a/42429550/1267661 answer's issue.
In Oracle a column of type "date" is not a number nor a string, it's a "datetime" value with year, month, day, hour, minute and seconds.
The default time is always midnight "00:00:00"
The query:
Select * From bdPedidos Where Data Like '%" + data + "%'"
won't work in all circumstances because a date column is not a string, using "like" forces Oracle to do a conversion from date value to string value.
The string value may be year-month-day-time or month-day-year-time or day-month-year-time, that all depends how a particular Oracle instance has set the parameter NLS_DATE_FORMAT to show dates as strings.
The right way to cover all the possible times in a day is:
Select *
From bdPedidos
Where Data between to_date('" + data + " 00:00:00','yyyy-mm-dd hh24:mi:ss')
and to_date('" + data + " 23:59:59','yyyy-mm-dd hh24:mi:ss')
SELECT * FROM myTab WHERE startDate like '%-%-2015';
This will search for all dates in 2015. If this doesn't work, try:
SELECT * FROM myTab WHERE startDate like '%-%-15';

finding data lying between a specific date range in sql

I want to find records from my database which lie between any user input date range(say between 10/2/2008 to 26/9/2024). I tried using
SELECT NAME
,TYPE
,COMP_NAME
,BATCH_NO
,SHELF
,MFG_DATE
,EXP_DATE
,QTY
,VAT
,MRP
FROM STOCK_LOCAL
WHERE
convert(VARCHAR(20), EXP_DATE, 103)
BETWEEN convert(VARCHAR(20), #MEDICINEEXP_DATE, 103)
AND convert(VARCHAR(20), #MEDICINEEXPDATE, 103)
but with this query i need to enter perfect date range which is available in my database, it is not giving me data lying in between any date entered.
Thanks in advance
Since it is a poolr designed schema there isnt going to be any decent/Efficient solution for this.
In sql server if you are storing Date or Date & Time data. Use the Data or DATETIME datatypes for your columns.
In your case you are trying to compare a string with passed date. and even when you tried to convert the string (Date) into date datatype you didnt do it correctly.
My suggestion would be Add new columns to your table with Date datatype and update these columns with existing date/string values.
For now you can convert the Date(string) into date datatype using the following code.
DECLARE #MEDICINEEXP_DATE DATE = 'SomeValue1'
DECLARE #MEDICINEEXPDATE DATE = 'SomeValue1'
SELECT query....
FROM TableName
WHERE
CAST(
RIGHT(EXP_DATE, 4)
+SUBSTRING(EXP_DATE,CHARINDEX('/',EXP_DATE)+1,2)
+LEFT(EXP_DATE,2)
AS DATE) >= #MEDICINEEXP_DATE
AND CAST(
RIGHT(EXP_DATE, 4)
+SUBSTRING(EXP_DATE,CHARINDEX('/',EXP_DATE)+1,2)
+LEFT(EXP_DATE,2)
AS DATE) <= #MEDICINEEXPDATE
Note
This solution will get you the expected results but very inefficient method. It will not make use of any indexses on your EXP_DATE Column even if you have a very buffed up index on that column.

Sybase date comparison - Correct format?

I'm pretty new to Sybase and am writing a query to return results after a specified date, and also before a specified date. MM/DD/YYYY format
At the moment im doing..
SELECT *
From aTable
WHERE afterDate >= 08/07/2013
AND beforeDate <= 08/08/2013
I'm getting records back, but as I'm a Sybase newbie, I want to be sure Sybase is interpreting these dates correctly..
Their online doc is pretty bad for basic explanations on things like this!
Anyone able to confirm if what I have works, or does it need some formatting round the dates?
You'll need to convert the dates into DATETIME and tell sybase what the format is to be sure.
According to this documentation the code for MM/DD/YYYY is 101, so something like this:
SELECT *
FROM aTable
WHERE afterDate >= CONVERT(DATETIME,'08/07/2013',101)
AND beforeDate <= CONVERT(DATETIME,'08/08/2013',101)
You can see the difference by running the following select statements:
SELECT CONVERT(DATETIME,'08/07/2013',101) --MM/DD/YYYY (2013-08-07 00:00:00.000)
SELECT CONVERT(DATETIME,'08/07/2013',103) --DD/MM/YYYY (2013-07-08 00:00:00.000)
For any date-time field in sybase, instead of going through the convert function, there is a more direct approach.
SELECT *
From aTable
WHERE afterDate >= '2013-08-07'
AND beforeDate <= '2013-08-08'
The date has to be in the form 'YYYY-MM-DD'
If you want to add a time, it can be included along with the date. The date and the time have to be separated by a T.
Any date time field can be directly used using the format 'YYYY-MM-DDTHH:MM:SS'
Using the functions is too lengthy. Noone needs a bazooka to shoot a squirrel! :)
CAST( '2000-10-31' AS DATE )
will convert from text to date format....
I am assuming that your two fields (afterDate and beforeDate) are in Date format.
Your example would be:
SELECT *
From aTable
WHERE afterDate >= CAST( '08/07/2013' AS DATE )
AND beforeDate <= CAST( '08/08/2013' AS DATE )
Also, usually (but not always) a date range is on the SAME field. As I said, that is not true all the time and you may have a good reason for that.
The best approach is to use the ANSI standard which does not require any conversion: yyyymmdd (you can also include hh:mm:ss) for instance:
DateField1 >= "20150101" and DateFile1 <= "20150102"
You should decide which Input-Strings the user is going to use as parameter and then convert them and concatenate them like you want, unless it is Datetime it is not important which initial format it had, you can use it in a between-condition.
E. g. the user is from Europe and uses "DD.MM.YY" and "hh:mm" as an input parameter, I would convert and concatenate like this:
WHERE dateCol between convert(DATETIME,
convert(char(11),
convert(DATETIME, '01.06.14', 4), 16) || ' ' || '00:00', 8)
AND convert(DATETIME,
convert(char(11),
convert(DATETIME, '01.07.14', 4), 16) || ' ' || '16:00', 8)

Date arithmetic in SQL on DB2/ODBC

I'm building a query against a DB2 database, connecting through the IBM Client Access ODBC driver. I want to pull fields that are less than 6 days old, based on the field 'a.ofbkddt'... the problem is that this field is not a date field, but rather a DECIMAL field, formatted as YYYYMMDD.
I was able to break down the decimal field by wrapping it in a call to char(), then using substr() to pull the year, month and day fields. I then formatted this as a date, and called the days() function, which gives a number that I can perform arithmetic on.
Here's an example of the query:
select
days( current date) -
days( substr(char(a.ofbkddt),1,4) concat '-' -- YYYY-
concat substr(char(a.ofbkddt),5,2) concat '-' -- MM-
concat substr(char(a.ofbkddt),7,2) ) as difference, -- DD
a.ofbkddt as mydate
from QS36F.ASDF a
This yields the following:
difference mydate
2402 20050402
2025 20060306
...
4 20110917
3 20110918
2 20110919
1 20110920
This is what I expect to see... however when I use the same logic in the where clause of my query:
select
days( current date) -
days( substr(char(a.ofbkddt),1,4) concat '-' -- YYYY-
concat substr(char(a.ofbkddt),5,2) concat '-' -- MM-
concat substr(char(a.ofbkddt),7,2) ) as difference, -- DD
a.ofbkddt as mydate
from QS36F.ASDF a
where
(
days( current date) -
days( substr(char(a.ofbkddt),1,4) concat '-' -- YYYY-
concat substr(char(a.ofbkddt),5,2) concat '-' -- MM
concat substr(char(a.ofbkddt),7,2) ) -- DD
) < 6
I don't get any results back from my query, even though it's clear that I am getting date differences of as little as 1 day (obviously less than the 6 days that I'm requesting in the where clause).
My first thought was that the return type of days() might not be an integer, causing the comparison to fail... according to the documentation for days() found at http://publib.boulder.ibm.com/iseries/v5r2/ic2924/index.htm?info/db2/rbafzmst02.htm, it returns a bigint. I cast the difference to integer, just to be safe, but this had no effect.
You're going about this backwards. Rather than using a function on every single value in the table (so you can compare it to the date), you should pre-compute the difference in the date. It's costing you resources to run the function on every row - you'd save a lot if you could just do it against CURRENT_DATE (it'd maybe save you even more if you could do it in your application code, but I realize this might not be possible). Your dates are in a sortable format, after all.
The query looks like so:
SELECT ofbkddt as myDate
FROM QS36F.ASDF
WHERE myDate > ((int(substr(char(current_date - 6 days, ISO), 1, 4)) * 10000) +
(int(substr(char(current_date - 6 days, ISO), 6, 2)) * 100) +
(int(substr(char(current_date - 6 days, ISO), 9, 2))))
Which, when run against your sample datatable, yields the following:
myDate
=============
20110917
20110918
20110919
20110920
You might also want to look into creating a calendar table, and add these dates as one of the columns.
What if you try a common table expression?
WITH A AS
(
select
days( current date) -
days( substr(char(a.ofbkddt),1,4) concat '-' -- YYYY-
concat substr(char(a.ofbkddt),5,2) concat '-' -- MM-
concat substr(char(a.ofbkddt),7,2) ) as difference, -- DD
a.ofbkddt as mydate
from QS36F.ASDF a
)
SELECT
*
FROM
a
WHERE
difference < 6
Does your data have some nulls in a.ofbkddt? Maybe this is causing some funny behaviour in how db2 is evaluating the less than operation.