Good morning,
I have a datetime column and when I do a SELECT query and ORDER BY the latest date it's returning results from a few weeks ago, which is correct, but when I CONVERT that datetime to a VARCHAR and ORDER BY this new CONVERTED column, it's a date from last year.
Apologies, it's for SQL-Server, here is the query:
SELECT TOP (5) [dbo].[UploadLog].[UploadLogID]
,[dbo].[UploadLog].[ChangedBy]
,CONVERT(VARCHAR(19),[dbo].[UploadLog].[LastChanged]) AS UploadDate
,[dbo].[UploadLog].[CompanyID]
FROM [dbo].[UploadLog]
WHERE [dbo].[UploadLog].[ChangedBy] = '5'
ORDER BY [UploadDate] desc
I'm not sure why this is happening but would appreciate any help.
Many thanks!
I believe your query contains ORDER BY after it converts to VARCHAR. Thats why you're getting the date from last year. You should ORDER BY first then CONVERT the result to VARCHAR. You can use inner queries or other ways to do this.
Btw, if you edit your question and add your query, we could help more effectively.
Related
I've written a query to check whether more than one record exists on the same day. Currently the excerpt from my query that performs the restriction looks like this :
GROUP BY
entry_date
HAVING
COUNT(entry_date) > 1
As the entry date column is defined as a datetime, does it check against the full datetime or just the date?
Thanks.
if entry_date is DATETIME ,your group by wont work as expected.you need to CAST it to DATE.Cast(Datetime)to date is sargable as well.
GROUP BY cast(entry_date as DATE)
having count(cast(entry_date as DATE)) > 1
Since you don't cast or convert it to anything else, naturally it uses all data available. So it would group data together with the exact same datetime. Why would you expect anything else?
It should be full datetime.
CONVERT(date, entry_date)
should separate out the date.
I wanted to know how to perform the SQL SELECT operation on only a particular range of characters.
For example,I've got an SQL query:
SELECT date,score from feedback GROUP BY date
Now this date is of format yyyy/mm/dd.
So I wanted to strip the days or cut out the days from it and make it yyyy/mm, thereby selecting only 0-7 characters from the date.
I've searched everywhere for the answer but could not find anything.Could I maybe do something like this?
SELECT date(7),score from feedback GROUP BY date(7)
In MSQL you use LEFT other use substring
SELECT LEFT('abcdefg',2);
--
ab
So in your case
SELECT LEFT(date,7), score
FROM feedback
GROUP BY LEFT(date,7)
But again things will be much easier if you use a date field instead a text field.
Assuming that your date field is an actual date field (or even a datetime field) the following solution would work:
select left(convert(date ,getdate()),7) as Year_Month
Changing getdate() to your date field, it would look like:
select left(convert(date , feedback.date),7) as Year_Month
Both queries return the following:
2016-01
There is this strange error in sql query.
The query is something like this.
select * from student where dob between '20150820' and '20150828'
But in the database the column of dob is varchar(14) and is in yyyyMMddhhmmss format,Say my data in the row is (20150827142545).If i fire the above query it should not retrive any rows as i have mentioned yyyyMMdd format in the query.But it retrives the row with yesterday date (i.e 20150827112535) and it cannot get the records with today's date (i.e 20150828144532)
Why is this happening??
Thanks for the help in advance
You can try like this:
select * from student
where convert(date,LEFT(dob,8)) between
convert(date'20150820') and convert(date,'20150828'))
Also as others have commented you need to store your date as Date instead of varchar to avoid such problems in future.
As already mentioned you would need to use the correct date type to have between behave properly.
select *
from student
where convert(date,LEFT(dob,8)) between '20150820' and '20150828'
Sidenote: You don't have to explicitly convert your two dates from text as this will be done implicitly as long as you use an unambiguous date representation, i.e. the ISO standard 'YYYYMMDD' or 'YYYY-MM-DD'. Of course if you're holding the values in variables then use date | datetime datatype
declare #startdate date
declare #enddate date
select *
from student
where convert(date,LEFT(dob,8)) between #startdate and #enddate
Sidenote 2: Performing the functions on your table dob column would prevent any indexes on that column from being used to their full potential in your execution plan and may result in slower execution, if you can, define the correct data type for the table dob column or use a persistent computed column or materialised view if your performance is a real issue.
Sidenote 3: If you need to maintain the time portion in your data i.e. date and time of birth, use the following to ensure all records are captured;
select *
from student
where
convert(date,LEFT(dob,8)) >= '20150820'
and convert(date,LEFT(dob,8)) < dateadd(d,1,'20150828')
All you have to do is to convert first the string to date.
select *
from student
where dob between convert(date, '20150820') and convert(date, '20150828')
Why is this happening?
The comparison is executed from left to right and the order of characters is determined by the codepage in use.
Sort Order
Sort order specifies the way that data values are sorted, affecting
the results of data comparison. The sorting of data is accomplished
through collations, and it can be optimized using indexes.
https://msdn.microsoft.com/en-us/library/ms143726.aspx
There are problems with between in T-SQL.
But if you want a fast answer convert to date first and use >= <= or even datediff to compare - maybe write a between function yourself if you want the easy use like between and no care about begin and start times ...
What do BETWEEN and the devil have in common?
The task:
I need to count every record in a table that was added after 07/01/2011.
Info:
There is a column in the table "Date_added" which is formatted as varchar and contains dates in format mm/dd/yyyy.
What I've tried:
I tried the following query:
SELECT count(date_added) FROM Abatements_Doc WHERE date_added >= '07/01/2011'
Unfortunately it counted any date where the month was greater than 07 regardless of the year or day. I'm at a loss as to how I should format my query to get it to read the dates properly instead of by ascii sort. In my research I discovered the CAST and CONVERT options, but am not sure how to use them, or which one I should use if any. I'm extremely new to SQL, and want to make sure I don't mess up the data in the table. I just need to get the count as specified above without altering the data in the table in any way. Any help in this regard will be very much appreciated. Thanks in advance.
I didn't test. But try convert statement.
SELECT count(date_added)
FROM Abatements_Doc
WHERE convert(datetime,date_added,1) >= convert(datetime,'07/01/2011',1)
(1) don't use mm/dd/yyyy as your date format. Use a safe and unambiguous format; the only one I trust for DATETIME/SMALLDATETIME is YYYYMMDD.
(2) change the data type in your table to DATETIME/SMALLDATETIME/DATE depending on accuracy required. Then `WHERE date_added >= '20110701' will work just fine (and will use an index on that column, if one exists).
(3) if you can't change the data type, then the following will work just fine as well (though no index will be used):
WHERE CONVERT(DATETIME, date_added, 101) >= '20110701'
Varchar can't be compared, try changing your column to date type.
Convert both date_added column values and your target date to DATETIME and compare; as in:
SELECT COUNT(1)
FROM Abatements_Doc
WHERE (CONVERT(datetime, date_added, 101)) >= CONVERT('07/01/2011', date_added, 101))
This seems stupid but, I simply need a list of dates to be ordered with the most recent date at top. Using order by DESC doesn't seem to be working the way I want it to.
SELECT *
FROM vw_view
ORDER BY EventDate DESC
It gives me the date ordered by month and day, but doesn't take year into consideration.
for example:
12/31/2009
12/31/2008
12/30/2009
12/29/2009
Needs to be more like:
12/31/2009
12/30/2009
12/29/2009
12/28/2009
and so on.
I'm guessing EventDate is a char or varchar and not a date otherwise your order by clause would be fine.
You can use CONVERT to change the values to a date and sort by that
SELECT *
FROM
vw_view
ORDER BY
CONVERT(DateTime, EventDate,101) DESC
The problem with that is, as Sparky points out in the comments, if EventDate has a value that can't be converted to a date the query won't execute.
This means you should either exclude the bad rows or let the bad rows go to the bottom of the results
To exclude the bad rows just add WHERE IsDate(EventDate) = 1
To let let the bad dates go to the bottom you need to use CASE
e.g.
ORDER BY
CASE
WHEN IsDate(EventDate) = 1 THEN CONVERT(DateTime, EventDate,101)
ELSE null
END DESC
try ORDER BY MONTH(Date),DAY(DATE)
Try this:
ORDER BY YEAR(Date) DESC, MONTH(Date) DESC, DAY(DATE) DESC
Worked perfectly on a JET DB.
You have the field in a string, so you'll need to convert it to datetime
order by CONVERT(datetime, EventDate ) desc
Assuming that you have the power to make schema changes the only acceptable answer to this question IMO is to change the base data type to something more appropriate (e.g. date if SQL Server 2008).
Storing dates as mm/dd/yyyy strings is space inefficient, difficult to validate correctly and makes sorting and date calculations needlessly painful.
what is the type of the field EventDate, since the ordering isn't correct i assume you don't have it set to some Date/Time representing type, but a string. And then the american way of writing dates is nasty to sort
If you restructured your date format into YYYY/MM/DD then you can use this simple string ordering to achieve the formating you need.
Alternatively, using the SUBSTR(store_name,start,length) command you should be able to restructure the sorting term into the above format
perhaps using the following
SELECT *
FROM vw_view
ORDER BY SUBSTR(EventDate,6,4) + SUBSTR(EventDate, 0, 5) DESC
Try this
SELECT *
FROM vw_view
ORDER BY DATE_FORMAT(EventDate, "%m-%d-%y") DESC