Date: Fri, 16 May 2008 11:09:17 -0400
Reply-To: Mark Smolkin <marksmolkin@GMAIL.COM>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: Mark Smolkin <marksmolkin@GMAIL.COM>
Subject: SQL confusion
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Hi..I am fairly new to SQL and am confused by a sentence in the SAS 9.1
SQL Procedure User's Guide. The text below is from pg. 41 and I don't
quite understand the second criteria mentioning the "where" clause. To
examine it, I created fake data and I saw that I could use a summary
function like "sum(cost)" as the lone item in the select clause, use a
where clause that subsetted on an a separate variable, and still receive
the correct overall sum without an error message. I am sure I am simply
misinterpreting the sentence and so I was hoping somebody could set me
straight....Appreciate the help!...
"In the previous example, PROC SQL combined information from multiple rows
of data into a single row of output. Specifically, the world oil reserves
for each country were combined to form a total for all countries.
Combining, or rolling up, of rows occurs when
the SELECT clause contains only columns that are specified within an
the WHERE clause, if there is one, contains only columns that are
specified in the SELECT clause."