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| author | Peter Eisentraut <peter@eisentraut.org> | 2020-09-04 08:19:20 +0200 |
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| committer | Peter Eisentraut <peter@eisentraut.org> | 2020-09-04 08:19:20 +0200 |
| commit | 6eee73e4e5b6d499f1a5529f209ce4af86ef5152 (patch) | |
| tree | eeaa386bb94b7d767c82f4ba79bc4a33fa0cafb8 /doc/src | |
| parent | 96cfcadd26e26e138ae60f4f3f94beddafba60bb (diff) | |
| download | postgresql-6eee73e4e5b6d499f1a5529f209ce4af86ef5152.tar.gz postgresql-6eee73e4e5b6d499f1a5529f209ce4af86ef5152.zip | |
doc: Use tags consistently in the tutorial chapter
Make more consistent use of <screen> and <programlisting>.
Author: Jürgen Purtz <juergen@purtz.de>
Discussion: https://www.postgresql.org/message-id/flat/158996922318.7035.10603922579567326239@wrigleys.postgresql.org
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/query.sgml | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/doc/src/sgml/query.sgml b/doc/src/sgml/query.sgml index c0889743c4c..bdb455f3008 100644 --- a/doc/src/sgml/query.sgml +++ b/doc/src/sgml/query.sgml @@ -564,14 +564,16 @@ SELECT * <programlisting> SELECT * FROM weather LEFT OUTER JOIN cities ON (weather.city = cities.name); +</programlisting> +<screen> city | temp_lo | temp_hi | prcp | date | name | location ---------------+---------+---------+------+------------+---------------+----------- Hayward | 37 | 54 | | 1994-11-29 | | San Francisco | 46 | 50 | 0.25 | 1994-11-27 | San Francisco | (-194,53) San Francisco | 43 | 57 | 0 | 1994-11-29 | San Francisco | (-194,53) (3 rows) -</programlisting> +</screen> This query is called a <firstterm>left outer join</firstterm> because the table mentioned on the left of the @@ -612,13 +614,15 @@ SELECT W1.city, W1.temp_lo AS low, W1.temp_hi AS high, FROM weather W1, weather W2 WHERE W1.temp_lo < W2.temp_lo AND W1.temp_hi > W2.temp_hi; +</programlisting> +<screen> city | low | high | city | low | high ---------------+-----+------+---------------+-----+------ San Francisco | 43 | 57 | San Francisco | 46 | 50 Hayward | 37 | 54 | San Francisco | 46 | 50 (2 rows) -</programlisting> +</screen> Here we have relabeled the weather table as <literal>W1</literal> and <literal>W2</literal> to be able to distinguish the left and right side |