根据当前日期计数寄存器

Question

I have a table who have creation date like:

SELECT [CreationDate] FROM Store.Order

So each register have one datetime like:

 2018-03-14 00:00:00.000
 2017-04-14 00:00:00.000
 2017-06-14 00:00:00.000

I want to know how to COUNT only register of Date equals to current month and year, for example in this case,if I only have one register in month 03 I just get 1 on count, how can I achieve it? Regards

Answer 1

Here is one option:

SELECT COUNT(*)
FROM Store.Order
WHERE
    CONVERT(varchar(7), [CreationDate], 126) = CONVERT(varchar(7), GETDATE(), 126);

Demo

We can convert both the creation date in your table and the current date into yyyy-mm strings, and then check if they be equal.

Answer 2

The most efficient way is to do:

where creationdate >= dateadd(day, 1 - day(getdate(), cast(getdate() as date)) and
      creationdate < dateadd(month, 1, dateadd(day, 1 - day(getdate(), cast(getdate() as date)))

Although this looks more complex than other solutions, all the complexity is on getdate() -- meaning that the optimizer can use indexes on creationdate .