This is probably a simple where clause but I want to say, from columnX (which is datetime) I want all rows where just the year = 2010.
so:
select * f
If i understand that you want all rows in the year 2010, then:
select *
from mytable
where Columnx >= '2010-01-01 00:00:00'
and Columnx < '2011-01-01 00:00:00'
T-SQL and others;
select * from t where year(Columnx) = 2010
its just simple
select * from myTable where year(columnX) = 2010
select * from mytable where year(Columnx) = 2010
Regarding index usage (answering Simon's comment):
if you have an index on Columnx, SQLServer WON'T use it if you use the function "year" (or any other function).
There are two possible solutions for it, one is doing the search by interval like Columnx>='01012010' and Columnx<='31122010' and another one is to create a calculated column with the year(Columnx) expression, index it, and then do the filter on this new column
NB: Should you want the year to be based on some reference date, the code below calculates the dates for the between
statement:
declare @referenceTime datetime = getutcdate()
select *
from myTable
where SomeDate
between dateadd(year, year(@referenceTime) - 1900, '01-01-1900') --1st Jan this year (midnight)
and dateadd(millisecond, -3, dateadd(year, year(@referenceTime) - 1900, '01-01-1901')) --31st Dec end of this year (just before midnight of the new year)
Similarly, if you're using a year value, swapping year(@referenceDate)
for your reference year's value will work
declare @referenceYear int = 2010
select *
from myTable
where SomeDate
between dateadd(year,@referenceYear - 1900, '01-01-1900') --1st Jan this year (midnight)
and dateadd(millisecond, -3, dateadd(year,@referenceYear - 1900, '01-01-1901')) --31st Dec end of this year (just before midnight of the new year)