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-- Tutorial on advanced more PostgreSQL features
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-- Copyright (c) 1994, Regents of the University of California
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-- $Id: advanced.source,v 1.5 2002/04/11 21:18:50 tgl Exp $
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-- A table can inherit from zero or more tables. A query can reference
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-- either all rows of a table or all rows of a table plus all of its
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-- For example, the capitals table inherits from cities table. (It inherits
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-- all data fields from cities.)
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altitude int -- (in ft)
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CREATE TABLE capitals (
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-- Now, let's populate the tables.
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INSERT INTO cities VALUES ('San Francisco', 7.24E+5, 63);
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INSERT INTO cities VALUES ('Las Vegas', 2.583E+5, 2174);
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INSERT INTO cities VALUES ('Mariposa', 1200, 1953);
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INSERT INTO capitals VALUES ('Sacramento', 3.694E+5, 30, 'CA');
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INSERT INTO capitals VALUES ('Madison', 1.913E+5, 845, 'WI');
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SELECT * FROM capitals;
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-- You can find all cities, including capitals, that
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-- are located at an altitude of 500 ft or higher by:
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SELECT c.name, c.altitude
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WHERE c.altitude > 500;
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-- To scan rows of the parent table only, use ONLY:
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-- clean up (you must remove the children first)