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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2001-01-08 21:30:37 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2001-01-08 21:30:37 +0000 |
| commit | 6334ef86a732ae4330dc1c4c65adab8059f864f3 (patch) | |
| tree | 411f57195d131a2864864109fff8f732e54fb952 | |
| parent | 005ad6cdd6507150246c12955c27ac2e995469ac (diff) | |
| download | postgresql-6334ef86a732ae4330dc1c4c65adab8059f864f3.tar.gz postgresql-6334ef86a732ae4330dc1c4c65adab8059f864f3.zip | |
Document that we don't support ORDER BY with general expressions on
the output of UNION/INTERSECT/EXCEPT.
| -rw-r--r-- | doc/src/sgml/ref/select.sgml | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 9dbc4958121..a34771571ec 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -1,5 +1,5 @@ <!-- -$Header: /cvsroot/pgsql/doc/src/sgml/ref/select.sgml,v 1.35 2000/12/12 05:07:59 tgl Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/ref/select.sgml,v 1.36 2001/01/08 21:30:37 tgl Exp $ Postgres documentation --> @@ -616,7 +616,12 @@ SELECT title, date_prod + 1 AS newlen FROM films ORDER BY newlen; <programlisting> SELECT name FROM distributors ORDER BY code; </programlisting> - + A limitation of this feature is that an ORDER BY clause applying to the + result of a UNION, INTERSECT, or EXCEPT query may only specify an output + column name or number, not an expression. + </para> + + <para> Note that if an ORDER BY item is a simple name that matches both a result column name and an input column name, ORDER BY will interpret it as the result column name. This is the opposite of the choice that |