How to get only a date from a datetime column? - sql

Question

I have a report to do, so I need to return a date from a datetime column, but it need to come only with the date from the column.
I am using the Microsoft SQL Server 2014. I've already tried to use CONVERT(name_of_the_column, GETDATE()) but I realised the it only works to return the current datetime from the server.
How can I do that?

Answer 1

Use CONVERT(DATE, <expression>).
create table t (dt datetime);
insert into t (dt) values ('2022-10-20 12:34:56');
select *, CONVERT(DATE, dt) from t;
Result:
dt (No column name)
----------------------- ----------
2022-10-20 12:34:56.000 2022-10-20
See example at db<>fiddle.

Answer 2

I prefer to use CAST instead.
CAST(name_of_the_field AS DATE)

Answer 3

I need to return a date from a datetime column
There are several things to cover in order to fully answer this.
First, if that really is a datetime column, something to understand here is datetime values will ALWAYS have a time component. It's even right there in the name. There is no way to return a datetime value that does not have a time portion. The closest you can get is casting to a string or date, but that's not really the same thing. Typically what happens instead is the time portion is truncated back to midnight (all 0s)... but that time portion is still there. That's where you see answers like this:
dateadd(dd, datediff(dd,0, name_of_the_column), 0)
or this:
CONVERT(varchar(10), name_of_the_column,101)
The next to thing to understand is the one thing you should not do is convert the date value to a string, as in the second example.
Because of cultural/internationalization issues, converting datetime or numeric values to and from strings is much slower and more error-prone than you'd like to believe. It's something to avoid, and probably best left to your client code or reporting tool.
A final consideration is datetime values NEVER have any time zone awareness (that would involve datetime2). So if there's anything on the client to show this in a local time it may be picking the wrong offset. Do that with a value where the time portion was already truncated, and you can end up with unexpected results.
Put all this together, and what you should do is CAST() to a DATE:
CAST(name_of_the_column AS DATE)
Now I have seen this comment on another answer with this recommendation:
keeps turning back time
This could be the time zone mismatch I've already mentioned, or it could also be that name_of_the_column is not really a datetime column in the first place, but rather a string/varchar column pretending to be a datetime column. In that case, the CAST() may be parsing the values with different cultural rules than you expect. It goes back to that whole "slower and more error-prone/something to avoid" thing again. Also in this is the case the schema is considered broken, and you really should fix it to use actual datetime or datetime2 values.
Speaking of "fix it", I also noticed the SQL Server 2014 tag. SQL Server 2014 has been fully end of life since 2019. That means it has not received any updates — not even critical security patches! — for several years now. It's dangerous and irresponsible to still be using it. Updating to a supported version is job #1 here.

Answer 4

I don't know why, but the only way that have returned the result I want to reach was using
CONVERT(VARCHAR, TB.COLUM, 103) AS 'NAME'.
But as mentioned before, this is not a good practice, and than I resolved to made do the convertion in the report tool of the system that am I working