Marginal tweaks in the documentation for ORDER BY; in particular point

out the common error that ORDER BY x, y DESC does not mean the same as
ORDER BY x DESC, y DESC.

diff --git a/doc/src/sgml/queries.sgml b/doc/src/sgml/queries.sgml
index 5c48ae1d625df6d2f08ae4afd767c155bcdde124..c427303db3a7135ef6a982c0d9fac0d0ce6a444f 100644 (file)
--- a/doc/src/sgml/queries.sgml
+++ b/doc/src/sgml/queries.sgml
@@ -1,4 +1,4 @@
-
+
 
 
  Queries
@@ -1262,6 +1262,13 @@ SELECT a, b FROM table1 ORDER BY a + b, c;
    DESC order, and NULLS LAST otherwise.
   
 
+  
+   Note that the ordering options are considered independently for each
+   sort column.  For example ORDER BY x, y DESC means
+   ORDER BY x ASC, y DESC, which is not the same as
+   ORDER BY x DESC, y DESC.
+  
+
   
    For backwards compatibility with the SQL92 version of the standard,
    a sort_expression can instead be the name or number

diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0af1fbb07a4b882118ffff65648c6e1336447c18..f77b805118d139b3a54d3b61886ea28a0df919f3 100644 (file)
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -1,5 +1,5 @@
 
 
@@ -644,13 +644,6 @@ HAVING condition
 
 ORDER BY expression [ ASC | DESC | USING operator ] [ NULLS { FIRST | LAST } ] [, ...]
 
-    expression can be the
-    name or ordinal number of an output column
-    (SELECT list item), or it can be an arbitrary
-    expression formed from input-column values.
-   
-
-   
     The ORDER BY clause causes the result rows to
     be sorted according to the specified expression(s).  If two rows are
     equal according to the leftmost expression, they are compared
@@ -659,6 +652,13 @@ ORDER BY expression [ ASC | DESC |
     an implementation-dependent order.
    
 
+   
+    Each expression can be the
+    name or ordinal number of an output column
+    (SELECT list item), or it can be an arbitrary
+    expression formed from input-column values.
+   
+
    
     The ordinal number refers to the ordinal (left-to-right) position
     of the result column. This feature makes it possible to define an
@@ -717,6 +717,12 @@ SELECT name FROM distributors ORDER BY code;
     on whether the operator is a less-than or greater-than operator.
    
 
+   
+    Note that ordering options apply only to the expression they follow;
+    for example ORDER BY x, y DESC does not mean
+    the same thing as ORDER BY x DESC, y DESC.
+   
+
    
     Character-string data is sorted according to the locale-specific
     collation order that was established when the database cluster