How can I use a SQL UPDATE statement to add 1 year to a DATETIME column?

Question

I want to add 1 year to a datetime-type column in every single row in a table. Adding using an UPDATE statement is easy for numeric types. ex:

UPDATE TABLE SET NUMBERCOLUMN = NUMBERCOLUMN + 1

I'd like to do the same thing with a DATETIME-type...

UPDATE Procrastination SET DropDeadDueDate = DropDeadDueDate + ?

...but I'm not sure what value to use. Is there a numeric value I could use that means "1 year"? Or is there a DATEADD function or similar in SQL Server?

Answer 1

There is in fact a DATEADD statement in T-SQL, you can find it here

UPDATE Procrastination SET DropDeadDueDate = DATEADD(yyyy,1,DropDeadDueDate)

EDIT: You could use year, yy, or yyyy for the first argument of DATEADD.

Answer 2

UPDATE Procrastination SET DropDeadDueDate =
DATEADD(yy, 1, DropDeadDueDate)

ref: http://doc.ddart.net/mssql/sql70/da-db_5.htm

Answer 3

The DateAdd function should do what you want.

UPDATE Procrastination SET DropDeadDueDate = DateAdd(yy, 1, DropDeadDueDate)

Answer 4

UPDATE Procrastination SET DropDeadDueDate = DATEADD(year, 1, DropDeadDueDate)

http://msdn.microsoft.com/en-us/library/ms186819.aspx

Answer 5

SQL Server has a DATEADD function.

http://msdn.microsoft.com/en-us/library/aa258267(SQL.80).aspx

Answer 6

It could be done with a DATEADD() function like this:

UPDATE Procrastination SET DropDeadDueDate = DATEADD(yy, 1, DropDeadDueDate)