Convert from varchar into date in SQL Server - sql

This looks easy solution but I can't seem to figure out as to why this is not working for me. I have a column that has data like this:
DateField
----------
12/16/2016
11/06/2016
All I want to do is to convert from varchar into a date column, but I am getting this error:
Conversion failed when converting date and/or time from character string.
Here is my simple query:
select convert (date, DateField) as convertedField
from myTable

Nothing wrong with the two examples you have given. There are some bad dates in your table which cannot be converted to date.
Use TRY_CONVERT function for bad dates it will return NULL
select TRY_Convert(date,DateField)
From myTable
You should always store dates in DATE/DATETIME datatype.
If you want to see the records which cannot be converted to date then
select DateField
From myTable
Where TRY_Convert(date,DateField) IS NULL

If working with a specific date format like mm/dd/yyyy You can specify it in Convert() function like the following
CONVERT(DATETIME,DATAFIELD,101)
If it still is not working, use TRY_CONVERT() to get which rows are throwing this exception:
SELECT *
FROM TBL
WHERE TRY_CONVERT(DATETIME, DATAFIELD, 101) IS NULL
This will return rows that cannot be converted
TRY_CONVERT() will return NULL if conversion failed
Read more about DateTime formats here:
SQL Server CONVERT() Function tutorial
Read TRY_CONVERT MSDN Article

You need to specify the format of date time while formatting. The date in your table is currently in U.S format so you should pass the third argument 101 in your convert function.
SELECT CONVERT(date,[DateField],101) FROM myTable;
Working Fiddle here http://rextester.com/NYKR49788
More info about date time style here: https://msdn.microsoft.com/en-us/library/ms187928.aspx

Related

Parse values of different type to date

I'm trying to parse certain columns into a date format and have had success doing so, but have run into an error due to inconsistency that lies in the data.
My date columns are currently integers in the form of YYYYMMDD, so I've used the following in the select statement to parse into dates:
CONVERT(datetime, CAST(date_column AS CHAR(8)), 112)
This works as expected, transforming my data into a YYYY-MM-DD format.
I run into the following error though:
Conversion failed when converting date and/or time from character
string.
After looking through the data a bit, it turns out I have some cases of inconsistent data values, such as -1 and 10630 instead of the expected YYYYMMDD value.
Do I just need to add a WHERE statement to only apply CONVERT and CAST to YYYYMMDD fields while filtering out fields with bad data? If so, how would I do this, or is there a better way?
Thanks in advance
Let me assume you are using SQL Server, based on the syntax of your SQL. You shouldn't actually need the 112. 'YYYYMMDD' is the default date format for SQL Server.
In any case, you can use TRY_CONVERT():
TRY_CONVERT(datetime, CAST(date_column AS CHAR(8)), 112)
This returns NULL if the value cannot be converted. You can find the offending values using:
select date_column
from t
where try_convert(datetime, cast(date_column as char(8)) is null and
date_column is not null;
Use Parse() or Try_parse()
select parse('22-JAN-1989' as date)
select parse('04-March-1992' as date)
select parse('03/10/2020' as date)
select parse('07-05-1958' as date)
select parse('Aug 25,2016' as date)
Every example above returns a valid date.
You can also add USING 'en-US' or such if you want a different culture.
If you are getting numeric values, and you know the starting date, use
select IsNull(try_parse('16500' as date),dateadd(d,cast('16500' as int),'1/1/1980'))

MM/dd/yyyy datetime data type resulted in an out-of-range value

I am inputting 2 date values in order to filter out from SQL query.
EXEC [Report].[usp_EmployeeReport_Detail] '01-01-2017','31-08-2019'
I am inputting the date as MM/dd/yyyy and the
WHERE clause contains
(j.StartDate BETWEEN #BegDate AND #EndDate)
I m getting the below error when executing the query.
The conversion of a nvarchar data type to a datetime data type resulted in an out-of-range value.
I tried to convert the datetime result using the below way as well.
SELECT CONVERT(datetime,01-31-2017,101)
This returns 1894-05-25 00:00:00.000 as the response. How its possible?
As #Damien_The_Unbeliever has said,01-31-2017 using the Numerical expression, which evaluates to -2047.
-2047 means the day minus 2047 days from 1900-01-01, so result of date will be 1894-05-25 00:00:00.000.
So your query SELECT CONVERT(datetime,01-31-2017,101) same as SELECT CONVERT(datetime,-2047,101)
sqlfiddle
You can use the ANSI compliant format YYYYMMDD
SELECT CONVERT(datetime,'20170131',101);
instead of
DD-MM-YYYY 01-31-2017.
Or just add ' to contain the date '01-31-2017' like #fa06 answered.
Try this: u've missed the quote in date:
SELECT CONVERT(datetime,'01-31-2017',101)
try below way
SELECT CONVERT(CHAR,GETDATE(),1 )
it returns 08/13/18
in your case you missed the quote as a result output that type shown

SQL - Convert String to Date and compare - Conversion failed when converting datetime from character string

I currently have dates stored in a general attribute field in the database as a string.
They are all stored in the format DD/MM/YYYY for example 01/01/2000
I am able to convert them them to datetime successfully by using the following in my select statement. For example CONVERT(DATETIME, attribute.field_value, 103) where attribute.field_value contains a date.
The SELECT statement works fine and returns the whole table with them correctly.
I can also return a column with todays date in the same format as follows CAST(getdate() AS datetime)
The problem occurs when I try to compare, now I only want to return everything that is newer than today in pseudo code that would dateNewerThanToday > dateToday
Therefore I have tried
WHERE CONVERT(DATETIME, attribute.field_value, 103) > CAST(getdate() AS datetime)
this gives me the error
Conversion failed when converting datetime from character string.
I have tried a multitude of cast/converts to get it to work. I have also wrapped by select so I am only doing it on dataset with the correct data.
Any help would be super useful! Many thanks in advance!!
A couple of things ..
You do not need to convert to GETDATE() to DATETIME data type as it already returns datetime data type.
Instead of CONVERT(DATETIME, attribute.field_value, 103)
use
CONVERT(DATETIME, attribute.field_value) or CAST(attribute.field_value AS DATETIME)
Add a where clause in your select to get only valid DATETIME values. something like
WHERE ISDATE(attribute.field_value) = 1
This will filter out any values which appears to be a date value but sql server doesnt see them as valid date values.
Important Not
Use appropriate data types. If this column is storing date values why not use the DATE or DATETIME data types.
I ran into this exact problem.
Values from a VARCHAR(50) column returned in the SELECT could be cast as date without issue. However when cast in a comparison in the WHERE clause the error occurred.
Of note, the error only occurred when I had other restrictions in the WHERE clause.
When I added ISDATE() to the WHERE clause, the error no longer occurred.
e.g. Shortened example of what worked:
SELECT CONVERT(DATE, mat.myAttributeColumn), mdct.myDateComparisonColumn
FROM myAttributeTable mat
JOIN myDateComparisonTable mdct ON mdct.key = mat.key
WHERE ISDATE(mat.myAttributeColumn) = 1
and mdct.myDateComparisonColumn < convert(DATE, mat.myAttributeColumn)

Convert NVARCHAR to DATETIME and select distinct Year

SELECT DISTINCT YEAR(convert(varchar(max),OrderCreatedDate)) from webshop
The above sql query is producing this error:
Conversion failed when converting date and/or time from character string.
The value in the database is NVARCHAR and in the following format: DD/MM/YYYY 00:00:00 AM (/PM)
I would like to select the unique values for the year only!
thanks for any help
To avoid this sort of issues, date should be saved in DateTime type field Not in a string field.
Year() function parameter is a DateTime type not a String. So you should make sure that the string you are passing is convertible to a DateTime type. In this case you could trim out the time part with Left() function and use 103 style as below.
Fiddle demo:
--Example
declare #val nvarchar(50) = '28/10/2013 11:25:45 AM (/PM)'
select year(convert(date,left(#val,10),103)) myYear
--Applying to your query
SELECT DISTINCT Year(Convert(Date,Left(OrderCreatedDate,10),103)) FROM Webshop
UPDATE:
If you are getting errors, it could be due to your date format. i.e. Format of the string you have saved may not be as you have described (DD/MM/YYYY 00:00:00 AM (/PM)) in the question.
Please check with ISDATE() function before converting to date and identify which records are causing the problem and correct them.
Try this query to get all of them with invalid strings. Following query will return 0 for values with invalid formatting.
SELECT DISTINCT CASE WHEN IsDate(eft(OrderCreatedDate,10))=1 THEN
Year(Convert(Date,Left(OrderCreatedDate,10),103))
ELSE 0 END as myDate,
OrderCreatedDate
FROM Webshop
Or you could get only the records which are causing the problem as;
SELECT OrderCreatedDate
FROM Webshop
WHERE IsDate(Left(OrderCreatedDate,10)) = 0
select distinct year(CONVERT(NVARCHAR(255),CONVERT(SMALLDATETIME, columnName,105)))
Try this
SELECT DISTINCT YEAR(Convert(datetime,OrderCreatedDate,103)) from webshop
DD/MM/YYYY 00:00:00 AM (/PM) is the British format. See Convert

datetime conversion issue in sql server

if i try to cast string date to datetime like
select cast('12/01/2010' as datetime) then
it works
but if i try to cast like
select cast('22/01/2010' as datetime) then it is giving error.
again if i try to cast string date to datetime like
select cast('2010/12/01' as datetime) then it works
but if i try to cast like
select cast('2010/25/01' as datetime) then it is giving error. my requirement is whatever way user input date that should be successfully converted to datetime. please tell me best solution
In your case the sql server assumes, that date format id mm/dd/yyyy - US format,
you want to use French format, so use convert
select CONVERT(DATETIME, '12/01/2010', 103)
instead you'll get an error because there in no such a month number - 22
The best solution when passing datetime as string - to use short(without timezone) ISO format:
yyyyMMdd HH:mm:ss.ffff
I recommend you to use fixed '20111231' format. You do not need to use cast, convert or similar command.