I have a varchar column with the following format ddmmyyyy and I'm trying to convert it to date in the format dd-mm-yyyy. I'm using the query below but I get the error:
Conversion failed when converting date and/or time from character string.
select *, coalesce(try_convert(date, newdate, 105), convert(date, newdate))
from mydate
You don't have a date, you have a string. So, you can use string operations:
select stuff(stuff(newdate, 5, 0, '-'), 3, 0, '-')
If you want to convert to a date, you can do:
select convert(date, concat(right(newdate, 4), substring(newdate, 3, 2), left(newdate, 2)))
You could then format this as you want.
However, you should not be converting the value to a date. You should be storing it as a date in the first place.
To turn your string to a date, you can just [try_]cast() it; SQL Server is usually flexible enough to figure out the format by itself:
try_cast(newdate as date)
If you want to turn it back to a string in the target format, then you can use format():
format(try_cast(newdate as date), 'dd-MM-yyyy')
Compared to pure string operations, the upside of the try_cast()/format() approach is that it validates that the string is a valid date in the process.
Have to agree with the others. Why are you storing a date as a string in the first place? In a non-standard format, no less? Here's one way, but you should really fix the data model. Store dates as dates.
DECLARE #badIdea table (dt char(8));
INSERT #badIdea(dt) VALUES('21052020');
SELECT newdate = TRY_CONVERT(date, RIGHT(dt,4) + SUBSTRING(dt,3,2) + LEFT(dt,2))
FROM #badIdea;
BTW 105 won't work because it requires dashes. This works:
SELECT CONVERT(date, '21-05-2020', 105);
That's a bad format too, IMHO, because who knows if 07-08-2020 is July 8th or August 7th. But at least that one is supported by SQL Server. Your current choice is not.
SQL doesn't store date data types in different formats, and it's probably not a good idea to try and adjust this.
If, however, you are wanting a result set to simply display the date in a different format, you are on the right track. You just need to convert your date data type to a string.
SELECT *
, COALESCE ( TRY_CONVERT ( CHAR(10), newdate, 105 ), CONVERT ( CHAR(10), newdate ) )
FROM mydate
Related
I have a date in format dd/mm/yyyy. I want to subtract one month from it.
I am using this code but the output is "09/10/2020" I don't know why my code does the subtraction of the year -2 also.
This is my request
SELECT
FORMAT(CONVERT (DATE, DATEADD(MONTH, -1, CONVERT(char(9), GETDATE()))), 'dd/MM/yyyy')
you need to change it to:
select format(CONVERT (date,DATEADD(MONTH, -1,GETDATE())), 'dd/MM/yyyy' )
but as Larnu stated. it seems like you need to change the column.
Your current code doesn't work as expected because:
SELECT CONVERT(char(9), GETDATE());
Returns this (at least in my language):
Nov 9 20
Which is, unfortunately, and again in my language, a valid date (but in {20}20, not {20}22).
Even in the right style (103), char(9) would yield 10/11/202 tomorrow, since 9 digits is only enough if either the day or month is a single digit.
Don't know why you are converting GETDATE() to a string. Just perform date math on it and then format it if you need to (using a specific style number, e.g. 103 for d/m/y):
SELECT CONVERT(char(10), DATEADD(MONTH, -1, GETDATE()), 103);
I really wouldn't use FORMAT() for such simple output, as the CLR overhead really isn't worth it. Ideally you leave it as a date/time type until presentation time - surely your presentation layer can present your date as d/m/y if that's really a wise idea.
And if you are storing or passing dates as strings (and worse, in regional formats like d/m/y) you really should consider fixing that.
First of all,
You should be storing your Date as a string for easier manipulation. If you don't want to change the column, you can always convert from Date to Varchar and then (re)convert it.
Example:
First, convert Date to varchar using the style code '112' ISO for formatting as yyyyMMdd:
DECLARE #date DATE = GETDATE();
DECLARE #dateConverted as VARCHAR (8) = (SELECT CONVERT(VARCHAR, #date, 112));
Then you just subtract the month using DATEADD():
DECLARE #previousMonth AS VARCHAR (8) = (SELECT FORMAT(DATEADD(month, -1, #dateConverted), 'yyyyMMdd'));
Finally, convert varchar do Date again:
DECLARE #previousMonthConverted AS DATE = (SELECT CONVERT(CHAR(10), CONVERT(date, #previousMonth), 120));
I have a date saved in an nvarchar type and I want to split the day, month and year into separate nvarchar variables (that means three variables). The date looks as follows: exposure_date ='2018-12-04' and the format is yyyy-dd-mm
any help please?
My whole project is stuck on this.
The "correct" answer here is to fix your datatype. When storing data always choose an appropriate data type for the data you're storing. For a date (with no time part) then the correct datatype is date. if you're storing numerical data, then use a numerical datatype, such as int or decimal. (n)varchar is not a one size fits all datatype and using it to store data that has a data type designed for it is almost always a bad choice. I'm storing the data as an (n)varchar because I need it in a specific format is never an excuse; have your presentation layer handle to display format, not your RDBMS.
The first step, therefore would be to change your string representation yyyy-dd-MM of a date to the ISO format yyyyMMdd by doing:
UPDATE YourTable
SET exposure_date = LEFT(exposure_date,4) + RIGHT(exposure_date,2) + SUBSTRING(exposure_date,6,2);
Now you have a unambiguous representation, you can change the data type of your column without concerns of incorrect implicit casts or error:
ALTER YourTable ALTER COLUMN exposure_date date;
Then, finally, you can treat your data as what it is, a date, and use the DATEPART function:
SELECT DATEPART(YEAR,exposure_date) AS Exposure_Year,
DATEPART(MONTH,exposure_date) AS Exposure_Month,
DATEPART(DAY,exposure_date) AS Exposure_Day
FROM YourTable;
You can also try the following
Declare #myDate date
select #myDate= Cast(substring('2011-29-12', 1, 4)
+ '-' + substring('2011-29-12', 9, 2)
+ '-' + substring('2011-29-12', 6, 2)
as Date) --YYYY-MM-DD
Select #myDate as DateTime,
datename(day,#myDate) as Date,
month(#myDate) as Month,
datename(year,#myDate) as Year,
Datename(weekday,#myDate) as DayName
The output is as shown below
DateTime Date Month Year DayName
--------------------------------------------
2011-29-12 29 12 2011 Thursday
You can find the live demo here
You can try below -
select concat(cast(year(cast('2018-12-04' as date)) as varchar(4)),'-',
cast(month(cast('2018-12-04' as date)) as varchar(2)), '-',
cast(day(cast('2018-12-04' as date)) as varchar(2)))
from tablename
If you have fixed format, then you could use this simple query with substring method:
select substring(dt, 1, 4) + '-' +
substring(dt, 9, 2) + '-' +
substring(dt, 6, 2) [YYYY-MM-DD]
from (values ('2018-31-12')) tbl(dt)
Let's go directly to the main issue, which is you are using the wrong datatype to store dates, you should store them as DATE, the datatypes are there for a reason and you need to choose a proper one for your column.
So, you need to ALTER your table and change the column datatype to DATE instead of NVARCHAR datatype.
ALTER <Table Name Here>
ALTER COLUMN <Column Name Here> DATE;
Then all things will easy, you just run the following query to get the desired output
SELECT YEAR(<Column Name Here>) TheYear,
MONTH(<Column Name Here>) TheMonth,
DAY(<Column Name Here>) TheDay
FROM <Table Name Here>
Which is the right and the best solution.
You can also (if you are not going to alter your table) do as
CREATE TABLE Dates(
StrDate NVARCHAR(10)
);
INSERT INTO Dates VALUES
(N'2018-12-04'),
(N'Invalid');
SELECT LEFT(StrDate, 4) StrYear,
SUBSTRING(StrDate, 6, 2) StrMonth,
RIGHT(StrDate, 2) StrDay
FROM Dates;
OR
SELECT YEAR(StrDate) StrYear,
MONTH(StrDate) StrMonth,
DAY(StrDate) StrDay
FROM (
SELECT TRY_CAST(StrDate AS DATE) StrDate
FROM Dates
)T
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;
I have VARCHAR column (MyValue) in my table. It has date value in two different format.
MyValue
----------
25-10-2016
2016-10-13
I would like to show them in DATE format.
I wrote query like below:
SELECT CONVERT(date, MyValue, 105) FROM MyTable
SELECT CAST(MyValue as date) FROM MyTable
Both are giving me this error. Conversion failed when converting date and/or time from character string.
Is there anyway convert to DATE datatype format even the value stored in different formats like above?
Expecting your answers. Thanks in advance.
Does this help?
declare #varchardates table
(
vcdate varchar(20)
)
INSERT INTO #varchardates VALUES
('25-10-2016'),
('2016-10-13')
SELECT CONVERT(date,vcdate, case when SUBSTRING(vcdate, 3, 1) = '-'
THEN 105 ELSE 126 END) as mydate
FROM #varchardates
Depending on how many different formats you have in your data, you may need to extend the case statement!
See here for list of the different format numbers
You can use TRY_CONVERT and COALESCE. TRY_CONVERT returns NULL if the conversion fails, COALESCE returns the first NOT NULL value:
SELECT COALESCE(TRY_CONVERT(DATETIME, x, 105), TRY_CONVERT(DATETIME, x, 120))
FROM (VALUES('25-10-2016'), ('2016-10-13')) a(x)
I assumed the value 2016-10-13 is in format yyyy-MM-dd.
You mention in a comment you may have other formats as well. In that case it gets very tricky. If you get a value 01-12-2017 and you have no idea about the format, there is no way to tell whether this is a date in januari or in december.
How do I convert a column which is date type to varchar?
Sample data:
ENDDATE (DATE TYPE)
'1947-12-01 00-00-00'
Requested results:
ENDDATE (VARCHAR)
121947
If I understand the question correctly, you need the ENDDATE of value '1947-12-01 00-00-00' as 121947. You can use the below query
SELECT RIGHT(MONTH(ENDDATE)*1010000+YEAR(ENDDATE),6)
If you are working with 2012 version or higher, you can use format. For earlier versions you can use convert with some string manipulations:
DECLARE #D as date = '1947-12-01'
SELECT REPLACE(RIGHT(CONVERT(char(10), #d, 103), 7), '/', '') As charValue2008,
FORMAT(#d, 'MMyyyy') as charValue2012
Results:
charValue2008 charValue2012
121947 121947
Please note that Format runs relativley slow, so if you have a lot of rows you might want to choose another way to do that.