Return date only (not time) - sql

I have a column that stores date information as a varchar(8). All of the data is entered as yyyymmdd. I would like to cast this information in a view to display as a date. When I try:
SELECT CAST(HIRE_DATE AS datetime)
The values are returned with the time. For example a record that has 19951107 casts as 1995-11-07 00:00:00.000.
How can I have it just return "1995-11-07" without the time value?

This would seem to be what you're looking for:
SELECT CONVERT(VARCHAR, CAST(HIRE_DATE AS DATETIME), 102)
Note that the return value is VARCHAR, not a true DATE, DATETIME, etc.
If you need it as a DATETIME datatype then omit the CONVERT.
SELECT CAST(HIRE_DATE AS DATETIME)
CAST and CONVERT should be helpful.

The answer from #DMason (cast(HIRE_DATE as datetime)) is the correct one if you have SQL Server 2005 or earlier.
SQL Server 2008 introduced the date datatype which means you can achieve what you want with cast(HIRE_DATE AS date).
If there are invalid dates in your varchar(8) column then cast() will cause the query the fail. SQL Server 2012 introduced the try_ conversion functions which return a null marker if the cast is impossible. So, you can achieve what you want with try_cast(HIRE_DATE AS date).
From Books Online: Conversion functions.

Related

SQL, casting a string to date so I can use GETDATE()

I am using SQL Server Management Studio 18 against SQL Server 2016. I have some material that are in batches and those batches have expiration dates that are held as strings, but are basically in the format of 'yearmonthday', e.g. '20210312' for March 3rd, 2021. My goal is to only see material that is expiring after the current date. Whenever I try to CAST the expiration date column AS DATE within the WHERE clause, I get this error:
Conversion failed when converting date and/or time from character string
(or something similar when trying different methods).
So, right now my code looks like this:
SELECT MaterialColumn, BatchColumn, CAST(ExpirationColumn AS DATE)
FROM StockTable
WHERE CAST(ExpirationColumn AS DATE) > CAST(GETDATE() AS DATE)
If I don't do the WHERE clause, I know I can CAST the ExpirationColumn as DATE without issue, but when it's in the WHERE clause, I run into that error. Is there any way I can filter to see only the dates that I want?
You can use try_cast() instead:
SELECT MaterialColumn, BatchColumn, CAST(ExpirationColumn AS DATE)
FROM StockTable
WHERE TRY_CAST(ExpirationColumn AS DATE) > CAST(GETDATE() AS DATE);
You can also find the bad values:
SELECT ExpirationColumn
FROM StockTable
WHERE TRY_CAST(ExpirationColumn AS DATE) IS NULL AND ExpirationColumn IS NOT NULL;
It sounds like you might need to fix some data values.
Honestly, if your dates are all stored in the format yyyyMMdd then there's no need to convert. Instead use a varchar parameter, as (at least) a varchar in the format yyyyMMdd had the same sort order as a date.
As a result you just convert GETDATE to the right format:
WHERE Expiration > CONVERT(varchar(8), GETDATE(), 112)
Of course, this doesn't change my statements in the comment; fix your design, don't stores dates as a string but as a date (and time) data type.

SQL How to format M/DD/YYYY (1/31/1960) to DD/MM/YYYY (31/01/1969)

I have a column that has date and time mixed together i.e. 1/31/1960 12:00:00AM and I would like to convert them into two-column through SQL function:
(a) DD/MM/YYYY i.e 31/01/1969
(b) HH:MM i.e 12:00
Thanks in advance.
Take a look at the CONVERT() function, specifically the style for datetime. Additionally, we can CAST() the DATETIME as a TIME data type to extract the time.
Assuming your original column is a DATETIME data type, you can run
SELECT
CONVERT(NVARCHAR(24),{DateField},103)
,CAST({DateField} AS TIME)
If it is string, you can cast it then convert
SELECT
CONVERT(NVARCHAR(24),CAST('1960-01-31' AS DATETIME),103) AS ReportingDate
,CAST(CAST('1960-01-31' AS DATETIME) AS TIME) AS ReportingTime
If you're on a sufficiently recent version of SQL Server, the FORMAT() function is your friend.
DECLARE #d DATE = GETDATE();
SELECT FORMAT(#d, 'dd/MM/yyyy');
Note, that second argument is a .NET formatting string, so you should be able to use whatever is available from the Framework.

How do I convert a value after using DATEADD with it

I have a little query that strips the date from the datetime field but when I try to convert it from GMT to CST it readds the date. Is there a better way to do this?
Location table:
arrival
4-6-2018 12:35:43
SELECT arrival
FROM(
SELECT CONVERT(VARCHAR(8), arrival))
FROM locations
)a
This query will give me this result:
12:35:43
SELECT (DATEADD(hour,-5,arrival))
FROM(
SELECT CONVERT(VARCHAR(8), arrival))
FROM locations
)a
4-6-2018 12:35:43
This query will give readd the date. How can I remove the date and then do the dateadd function without it readding the date
arrival seems to be a DateTime, which always carries a date part. You need a time instead, supported by SQL Server 2008+:
cast(DATEADD(hour,-5,arrival) as time)
To quote from DATEADD (Transact-SQL) - Return Types:
The return data type is the data type of the date argument, except for string literals. The return data type for a string literal is datetime. An error will be raised if the string literal seconds scale is more than three positions (.nnn) or contains the time zone offset part.
Emphasis my own.
As you are passing a string (varchar), then DATEADD is returning a datetime.
Like those in the comments have said, if you use the correct data type (time) this problem goes away:
SELECT DATEADD(HOUR, -5,CONVERT(time,Arrival))
FROM (VALUES('4-6-2018 12:35:43'),('4-6-2018 07:35:43'),('4-6-2018 03:35:43')) V(Arrival)
Probably this is what you are asking for:
SELECT Convert(Varchar(8), DATEADD(hour,-5,arrival), 108)
FROM locations;
Note: This is compatible with SQL server versions that doesn't have Time datatype too.

Convert from varchar into date in SQL Server

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

varchar vs datetime in sql

I was having problem in retrieving from SQL Server so I posted this [question][1]
I did not get any suitable answers. So I have changed the column datatype from datetime to varchar and now it works fine.
SELECT *
FROM test
WHERE (timeStamp BETWEEN '05-09-2013 18:23:57' AND '05-09-2013 18:23:59')
But my query if varchar datatype can play the role of datetime and in varchar we can also store the string then why sql provides datetime datatype? I know varchar occupies more space than datetime. I would like to know other reasons.
Change datatype of your column to datetime. You can do your query IF you'll use datetime instead of varchar in where clause:
select *
from test
where timeStamp between convert(datetime, '2013-09-05 18:23:57', 120) and convert(datetime, '2013-09-05 18:23:59', 120)
I'm pretty sure it would work even with implicit cast if you use ISO format of date:
select *
from test
where timeStamp between '2013-09-05 18:23:57' and '2013-09-05 18:23:59'
Here's more info about cast and convert.
Another reason apart from space is this:
Datetime has other functions like picking up the day, year, month,hours,minutes,seconds etc so that you don't have to write it for yourself. If you use varchar then it will be your responsibility to provide functions for future use. You should use split function to retrive the part of date you want.
Another is that a query on a varchar works slower when compared to Datetime when you use to conditions to compare month / day/ year
Always use proper DATETIME datatype to store date and time values. Refer this for more information
http://beyondrelational.com/modules/2/blogs/70/posts/10902/understanding-datetime-column-part-iv.aspx