Re: How to do a difference on two sets from same table?
Date: Tue, 31 Aug 2004 09:01:16 -0500
On 8/30/2004 10:26 PM, Alan wrote:
> Complete SQL? Can we have your complete salary (or grade)? Minus:
> SELECT your_columns_of_interest
> FROM wherever
> WHERE some_condition
> SELECT same_columns_as_above
> FROM same_place
> WHERE other_condition
> You are subtracting one set from another set. It is important to keep the
> set notion in mind when you construct this and interpret the results. In the
> above, you will see all rows that are in the first part of the query, but
> are not in the 2nd part.
> You must learn how to use MINUS. It is as important as joins.
> "Dan" <dan_at_nospam.com> wrote in message
>>I don't know what you mean. Could someone give me the complete SQL? >> >>TIA, >>Dan >> >>On 8/30/2004 2:55 AM, pstnotpd wrote: >> >>>Have a look at MINUS >>> >>> >>>Dan wrote: >>> >>> >>>>Hi, >>>> >>>>Say I have a sales history table that has the following fields: >>>>custid, invoicedate, prodid, quantity, cost, sale. And that I want to >>>>select sales records where invoicedate is between 5/1/04 and 8/31/04 >>>>and where these are new sales for each customer, meaning that the >>>>customer did not buy the prodid in the period 1/1/04 to 4/30/04. I >>>>know conceptually that this is a difference between two sets based on >>>>custid+prodid but I don't know how to express this in SQL. Please
>>>>Dan Received on Tue Aug 31 2004 - 16:01:16 CEST