Sybase date comparison - Correct format? - sql

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)

Related

Convert string to date SQL Server

I have a query when I need to convert a string to datetime, I use
CONVERT(DATETIME, '')
but it's still not working. My column fechac is of type Datetime.
If I pass in for example '2019-11-20 00:03:56.120', the query works but I don't need the time because is a parameter from an application web and I send the date example '2019-11-20'. Thanks!
This is my query:
SELECT *
FROM table
WHERE cb.fechac = CONVERT(DATETIME, '2019-11-20');
Use the format yyyyMMdd. With the datetime datatype yyyy-MM-dd is ambiguous. Otherwise, use a style code:
CONVERT(datetime,'2019-11-20',126);
CONVERT(datetime,'20191120')
Reading a lot through the lines in the comments here, however, are you actually after..?:
WHERE fechac >= '20191120'
AND fechac < '20191121'
Final reading through the lines. it appears the OP is actuaklly passing a parameter (I assume of the data type date), therefore...
WHERE fechac >= #fechac
AND fechac < DATEADD(DAY, 1, #fechac)
This should work on any system, regardless of internationalization settings:
WHERE cb.fechac=convert(DATE,'20191120');
SELECT *
FROM table cb
WHERE cast(cb.fechac as date) = convert(date, '2019-11-20', 23)

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;

Converting string 'yyyy-mm-dd' to date

I want to select from table where date column is equal to specific date which I sending as a string in format 'yyyy-mm-dd'. I need to convert that string and than to compare if I have that date in my table.
For now I am doing this:
select *
FROM table
where CONVERT(char(10), date_column,126) = convert(char(10), '2016-10-28', 126)
date_column is a date type in table and I need to get it from table in this format 'yyyy-mm-dd' and because that I use 126 format. I am just not sure with the other part where I converting string which is already in that format and do I need to convert it because I don't know is it good to use this:
CONVERT(varchar(10), date_column,126) = '2016-10-28'
You don't need to convert the column as well. In fact, you better not convert the column, because using functions on columns prevents sql server from using any indexes that might help the query plan on that column.
Also, you are converting a string to char(10) - better just convert it to date:
where date_column = convert(date, '2016-10-28', 126)
Also, if you are using a datetime data type and not date, you need to check that the datetime value is between the date you pass to the next date.
You can convert string to date as follows using the CONVERT() function by giving a specific format of the input parameter
declare #date date
set #date = CONVERT(date, '2016-10-28', 126)
select #date
You can find the possible format parameter values for SQL Convert date function here
You do not need to do that. yyyy-MM-dd is the default format.
Please note that you need to take into account the time as well, if there's a timestamp in date_column. In that case you should write something like this
... WHERE date_column >= '2016-10-28 00:00:00' AND date_column < '2016-10-29 00:00:00'
... WHERE date_column BETWEEN '2016-10-28 00:00:00' and '2016-10-29 00:00:00'
As I just learned that (other than I thought) BETWEEN actually includes the end timestamp and thus is not equivalent to the above >= ... < approach.
This should use indexes properly as well.

how to remove time from datetime

The field DATE in the database has the following format:
2012-11-12 00:00:00
I would like to remove the time from the date and return the date like this:
11/12/2012
First thing's first, if your dates are in varchar format change that, store dates as dates it will save you a lot of headaches and it is something that is best done sooner rather than later. The problem will only get worse.
Secondly, once you have a date DO NOT convert the date to a varchar! Keep it in date format and use formatting on the application side to get the required date format.
There are various methods to do this depending on your DBMS:
SQL-Server 2008 and later:
SELECT CAST(CURRENT_TIMESTAMP AS DATE)
SQL-Server 2005 and Earlier
SELECT DATEADD(DAY, DATEDIFF(DAY, 0, CURRENT_TIMESTAMP), 0)
SQLite
SELECT DATE(NOW())
Oracle
SELECT TRUNC(CURRENT_TIMESTAMP)
Postgresql
SELECT CURRENT_TIMESTAMP::DATE
If you need to use culture specific formatting in your report you can either explicitly state the format of the receiving text box (e.g. dd/MM/yyyy), or you can set the language so that it shows the relevant date format for that language.
Either way this is much better handled outside of SQL as converting to varchar within SQL will impact any sorting you may do in your report.
If you cannot/will not change the datatype to DATETIME, then still convert it to a date within SQL (e.g. CONVERT(DATETIME, yourField)) before sending to report services and handle it as described above.
just use, (in TSQL)
SELECT convert(varchar, columnName, 101)
in MySQL
SELECT DATE_FORMAT(columnName, '%m/%d/%Y')
I found this method to be quite useful. However it will convert your date/time format to just date but never the less it does the job for what I need it for. (I just needed to display the date on a report, the time was irrelevant).
CAST(start_date AS DATE)
UPDATE
(Bear in mind I'm a trainee ;))
I figured an easier way to do this IF YOU'RE USING SSRS.
It's easier to actually change the textbox properties where the field is located in the report. Right click field>Number>Date and select the appropriate format!
SELECT DATE('2012-11-12 00:00:00');
returns
2012-11-12
Personally, I'd return the full, native datetime value and format this in the client code.
That way, you can use the user's locale setting to give the correct meaning to that user.
"11/12" is ambiguous. Is it:
12th November
11th December
For more info refer this: SQL Server Date Formats
[MM/DD/YYYY]
SELECT CONVERT(VARCHAR(10), cast(dt_col as date), 101) from tbl
[DD/MM/YYYY]
SELECT CONVERT(VARCHAR(10), cast(dt_col as date), 103) from tbl
Live Demo
TSQL
SELECT CONVERT(DATE, GETDATE()) // 2019-09-19
SELECT CAST(GETDATE() AS DATE) // 2019-09-19
SELECT CONVERT(VARCHAR, GETDATE(), 23) // 2019-09-19
In mysql at least, you can use DATE(theDate).
You may try the following:
SELECT CONVERT(VARCHAR(10),yourdate,101);
or this:
select cast(floor(cast(urdate as float)) as datetime);
Use this SQL:
SELECT DATE_FORMAT(date_column_here,'%d/%m/%Y') FROM table_name;

How to filter only the date from a string stored in a varchar

Ii have values stored in the SQL Server in the following manner : 02-Jul-12 12:00:00 AM here the time and minutes, seconds can be anything like 02-Jul-12 12:15:52 PM ,02-Jul-12 6:02:12 AM so on.
I want to have a where condition which will omit the time and take the data based on the date like the following where some_Date='02-Jul-12'
How would I do this?
SELECT * FROM whatever WHERE some_Date LIKE '02-Jul-12%';
If you are on SQL2008 or later, you can cast your DATETIME to DATE.
See this post: http://blog.sqlauthority.com/2012/09/12/sql-server-get-date-and-time-from-current-datetime-sql-in-sixty-seconds-025-video/
But in a WHERE-clause it is better to search between dates, like this:
DECLARE #startDate DATETIME = '02-Jul-2012'
DECLARE #endDate DATETIME = DATEADD(DAY, 1, #startDate)
SELECT * FROM [table] WHERE [some_Date] BETWEEN #startDate AND #endDate
SELECT * FROM dbo.tbl_MyTable
WHERE
REPLACE(CONVERT(VARCHAR(9), DateTimeValueColumn, 6), ' ', '-')='02-Jul-12'
or
On chage in code is instead of using getdate function voncert you datestring in datetime format and do compare this follow query will work for you
SELECT * FROM dbo.tbl_MyTable
WHERE
CAST(CONVERT(CHAR(10), DateTimeValueColumn, 102) AS DATE) =
CAST(CONVERT(CHAR(10),GETDATE(),102) AS DATE)
If you are storing dates as characters -- which is not recommended -- you should at least use ISO format: YYYY-MM-DD hh:mm:ss. This makes the date useful for sorting and comparisons ("<" works, ">" works, "between" works as well as equals).
To extract the date, you can then use left(datestr, 10). In your format, you would use:
where left(datestr, 9) = '01-Jan-13'
If you are storing the fields as a datetime or smalldatetime, you may think they are stored as a string. They are not. They are stored as some number of days since some particular date, with day parts stored as fractional days. If you are using SQL Server 2005 or greater, then the best way is:
where cast(datetime as date) = '2013-01-01' -- I recommend ISO formats, even for constants. '20130101' is even better
To select rows with today's date (not time)
select * from myTable where datediff(dd, dateColumn, getdate()) = 0