The SQL DateAdd function queries data from recent years and months.

Instance

Suppose we have the following "Orders" table:

OrderId ProductName OrderDate

1 'computer '16:25:46. 635

Now, we want to add 2 days to "OrderDate" so that we can find the payment date.

We use the following SELECT statement:

The code is as follows:	Copy code
SELECT OrderId, DATEADD (day, 2, OrderDate) AS OrderPayDate FROM Orders

Select DateAdd (Month,-3, getdate () -- Returns a time, based on which you can query the desired data.

-- Example:

The code is as follows:	Copy code
Select DateAdd (Month,-3, getdate () -- takes the current time as the standard and returns a time point three months ago. Select DateAdd (yyyy,-3, getdate () -- Returns a time point three years ago based on the current time. Select DateAdd (Month, 3, getdate () -- Returns a time point after three months based on the current time.

Datepart	Abbreviations
Year	Yy, yyyy
Quarter	Qq, q
Month	Mm, m
Day of the year	Dy, y
Day	Dd, d
Week	Wk, ww
Week	Dw, w
Hours	Hh
Minutes	Mi, n
Seconds	Ss, s
Millisecond	MS
Subtle	Mcs
Nanoseconds	Ns

-- Indicates the number of time intervals to be added. A numeric expression can be a positive number (to get the future date) or a negative number (to get the past date ).
-- Date is required. The comparison time during Query. getdate () indicates the current time in SQL.