I have a table with two columns, all of them are datetime value
Such as, Column A with value ‘07/09/2012 14:13:34’
Now, I want to update column A to yyyymmdd by statement
Update Change_Date
SET A = CONVERT(VARCHAR(8),A,112)
It shows succsessful message but with no effect (no update value to 20120907) in my table Change_Date.
Any help will be greated, thank you!
A datetime fields saves a date time. How you see that date time is a result of the tool you're using to inspect the data, whether it is Management Studio, or your own software that's printing something from the database.
I strongly recommend keeping it as a datetime field. This will allow you to do date-related operations, such as subtractions and comparisons. If you want to change how your users see the date, then format your date at the presentation layer.
What's happening in the code you've posted is that you're setting the value of A to the same date that it already is. The fact that you're setting that value by means of a string in another format has no relation, SQL server will always have to parse your string input into a date that it can understand. This is why you're not getting an error message. The operation is working, only it's not changing anything.
You can select the date column in specified format or make a view which selects the column value in yyyymmdd format:
SELECT CONVERT(VARCHAR(8), A, 112) FROM Change_Date
It's because the datatype of the column is DATE or DATETIME and it has specific format. If you want to update the column with specific format, make another column and make its datatype VARCHAR. I believe 112 is yyyymmdd format.
I strongly suggest that you keep it AS IS. Database is the storage of data and not for viewing purposes. It is easy to perform task for dates if your data type is DATETIME or DATE. If for instance you want to retrieve the dates with specific format, that's the time you convert your date.
Hope this makes sense.
Related
I need help in figuring out the date conversion logic in Snowflake. The documentation isn't clear enough on this.
In SQL Server, I would try
SELECT CONVERT(DATE, '20200730', 101)
and it gives me '07/30/2020'.
If I try the following in Snowflake,
to_varchar('20200730'::date, 'mm/dd/yyyy')
it gives me '08/22/1970'. Why would it give an entire different date? Need help in getting the logic with the correct date.
The issue with what you are doing is that you are assuming that Snowflake is converting your string of '20200730'::DATE to 2020-07-03. It's not. You need to specify your input format of a date. So, 2 options based on your question being a bit vague:
If you have a string in a table and you wish to transform that into a date and then present it back as a formatted string:
SELECT TO_VARCHAR(TO_DATE('20200730','YYYYMMDD'),'MM/DD/YYYY');
--07/30/2020
If the field in the table is already a date, then you just need to apply the TO_VARCHAR() piece directly against that field.
Unlike SQL Server, Snowflake stores date fields in the same format regardless of what you provide it. You need to use the TO_VARCHAR in order to format that date in a different way...or ALTER SESSION SET DATE_OUTPUT_FORMAT will also work.
Try select to_varchar(TO_DATE( '20200730', 'YYYYMMDD' ), 'MM/DD/YYYY'); which produces 2020-07-30
You may need to refer to https://docs.snowflake.com/en/user-guide/date-time-input-output.html#timestamp-formats
I have over 65 columns among which there are about 30 Date Columnns. I want to set it to MM/DD/YYYY. Presently it is also showing the time YYYY-MM-DD hh:mm:ss. I tried correcting this within the SQL query by using cast. The SQL output shows only date, but it again gets represented in DateTime in SSRS. I dont want to right click on 30 columns manually to set date format. Is there a way to set default date format for all date columns in the report?
"Cast" is not helping here since it is about types, not format.
Try using the "convert" function instead.
In your case, it would be
-- use your field name instead of sysdatetime()
select convert(varchar, sysdatetime(), 101/*mm/dd/yyyy format Id*/);
You should be able to select all the fields in the tablix and change the formatting together. You may wish to consider using a parameter for the formatting.
I added named query to my data source view, converting datetime to date. When I run the query it displays datetime anyway. Do you know how to fix this? I need date format to match with the Time dimension.
I'm using SQL Server Data Tools 2012.
The SQL DATE datatype accepts time values, so that is how it is shown in the Query preview. If the datatype of your Time dimension key is also DATE, then you should be OK to continue. Have you tried?
FWIW I would use a BIGINT key for a Date Dimension, containing a date represented as YYYYMMDD. This allows for extra rows e.g. with a -1 Key for unspecified dates (e.g. null in Fact data).
I have to run column checks for data consistency and the only thing that is throwing off my code is checking for character lengths for dates between certain parameters.
SEL
sum(case when ( A.date is null or (character_length(A.date) >8)) then 1 else 0 end ) as Date
from
table A
;
The date format of the column is YYYY-MM-DD, and the type is DA. When I run the script in SQL Assistant, I get an error 3580 "Illegal use of CHARACTERS, MCHARACTERS, or OCTET_LENGTH functions."
Preliminary research suggests that SQL Assistant has issues with the character_length function, but I don't know how to adjust the code to make it run.
with chareter length are you trying to get the memory used? Becuase if so that is constant for a date field. If you are trying to get the length of the string representation i think LENGTH(A.date) will suffice. Unfortanatly since teradata will pad zeros on conversions to string, I think this might always return 10.
UPDATE :
Okay so if you want a date in a special 'form' when you output it you need to select it properly. In teradata as with most DBs Date are not store in strings, but rather as ints, counting days from a given 'epoch' date for the database (for example the epoch might be 01/01/0000). Each date type in teradata has a format parameter, which places in the record header instructions on how to format the output on select. By default a date format is set to this DATE FROMAT 'MM/DD/YYYY' I believe. You can change that by casting.
Try SELECT cast(cast(A.date as DATE FORMAT 'MM-DD-YYYY') as CHAR(10)) FROM A. and see what happens. There should be no need to validate the form of the dates past a small sample to see if the format is correct. The second cast forces the database to perform the conversion and use the format header specified. Other wise what you might see is the database will pass the date in a date form to SQL Assitant and sql assitant will perform the conversion on the application level, using the format specified in its own setting rather then the one set in the database.
I am seeeing my dates are stored in database in this format for a column (datetime datatype) 2011-01-14 10:15:41.787 i.e YYYY-MM-DD way . How could I make the default storage in YYYY-DD-MM format . Do I need to set that for all the DBS, or I can set it for single DB and how ?
I have the column in datetime datatype, right now it is saving as
2011-01-14 10:15:41.787 , my question is how can I set the db to store it as
2011-14-01 10:15:41.787
That is the crux of the confusion. Just because SQL Server Management Studio displays a datetime column in that format does not mean that it is stored AS TEXT YYYY-MM-DD hh:mm:ss.zzz. It is stored as binary, something like 0000101000001010..
Your dates are stored in SQL Server as a series of bytes (bits really) that make up some numeric value that is an offset from 1900-01-01. There is no inherent format the the dates. What you are referring to is that SSMS by default shows [display] datetime columns as YYYY-MM-DD hh:mm:ss.zzz. If you use a front-end programming tool, that too may impose a default [display] format unless you have asked for another one.
There is absolutely NO way to make SSMS show datetime data in another format through options or configuration. If you must, you would have to update the SQL query to convert the datetime column to a VARCHAR column containing the TEXTual equivalent in a particular format. That may be useful in SSMS, but would be bad when used as a data source to front-end GUI/web apps - since the values are not datetime and cannot be used for interval calculation, graphing, bound to date controls etc.
See this example of displaying time (getdate()) as YYYY-DD-MM, a very unusual format. Notice the date field/variable has to be used twice:
select stuff(convert(char(7), getdate(), 120), 5, 0, '-' + convert(char(2), getdate(), 3))
DATETIMEs are stored internally as two 4 byte integers, so firstly you are seeing a formatted representation for the UI - it's not actually stored in a particular date/time format as such.
e.g. if you insert just a date like "2010-01-01" then it will still hold the time element: 2010-01-01 00:00:00.000
If you're only interested in the DATE part, then you can format the DATETIME for output either in your front-end code or via your query:
e.g.
SELECT CONVERT(VARCHAR(8), GETDATE(), 121)
So even if the DATEs you insert contain a time, that will be ignored when returned. You could also ensure you only insert dates without the time specified - you need to handle that in whatever code is doing the INSERTs. e.g. from .NET, instead of passing in DateTime.Now you could pass in DateTime.Now.Date.
In SQL Server 2008, there is a DATE datatype which is there to only store a DATE (without time) which is really what you want in this kind of scenario.