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New blood and fresh air for tutorial

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This commit is contained in:
Peter Eisentraut
2001-09-02 23:27:50 +00:00
parent 5608f13028
commit 60ce9e9279
9 changed files with 1352 additions and 1141 deletions
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75
src/tutorial/advanced.source
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@ -1,19 +1,18 @@
---------------------------------------------------------------------------
--
-- advanced.sql-
-- more POSTGRES SQL features. (These are not part of the SQL-92
-- standard.)
-- Tutorial on advanced more PostgreSQL features
--
--
-- Copyright (c) 1994, Regents of the University of California
--
-- $Id: advanced.source,v 1.3 1999/07/08 15:28:51 momjian Exp $
-- $Id: advanced.source,v 1.4 2001/09/02 23:27:50 petere Exp $
--
---------------------------------------------------------------------------
-----------------------------
-- Inheritance:
-- a table can inherit from zero or more tables. A query can reference
-- S table can inherit from zero or more tables. A query can reference
-- either all rows of a table or all rows of a table plus all of its
-- descendants.
-----------------------------
@ -31,7 +30,7 @@ CREATE TABLE capitals (
state char(2)
) INHERITS (cities);
-- now, let's populate the tables
-- Now, let's populate the tables.
INSERT INTO cities VALUES ('San Francisco', 7.24E+5, 63);
INSERT INTO cities VALUES ('Las Vegas', 2.583E+5, 2174);
INSERT INTO cities VALUES ('Mariposa', 1200, 1953);
@ -56,72 +55,6 @@ FROM cities* c
WHERE c.altitude > 500;
-----------------------------
-- Time Travel:
-- this feature allows you to run historical queries.
-- removed for v6.3, but possible using triggers.
-- see contrib/spi/README for more information.
-----------------------------
-- first, let's make some changes to the cities table (suppose Mariposa's
-- population grows 10% this year)
-- UPDATE cities
-- SET population = population * 1.1
-- WHERE name = 'Mariposa';
-- the default time is the current time ('now'):
-- SELECT * FROM cities WHERE name = 'Mariposa';
-- we can also retrieve the population of Mariposa ever has. ('epoch' is the
-- earliest time representable by the system)
-- SELECT name, population
-- FROM cities['epoch', 'now'] -- can be abbreviated to cities[,]
-- WHERE name = 'Mariposa';
----------------------
-- Arrays:
-- attributes can be arrays of base types or user-defined types
----------------------
CREATE TABLE sal_emp (
name text,
pay_by_quarter int4[],
schedule text[][]
);
-- insert instances with array attributes. Note the use of braces
INSERT INTO sal_emp VALUES (
'Bill',
'{10000,10000,10000,10000}',
'{{"meeting", "lunch"}, {}}');
INSERT INTO sal_emp VALUES (
'Carol',
'{20000,25000,25000,25000}',
'{{"talk", "consult"}, {"meeting"}}');
----------------------
-- queries on array attributes
----------------------
SELECT name FROM sal_emp WHERE
sal_emp.pay_by_quarter[1] <> sal_emp.pay_by_quarter[2];
-- retrieve third quarter pay of all employees
SELECT sal_emp.pay_by_quarter[3] FROM sal_emp;
-- select subarrays
SELECT sal_emp.schedule[1:2][1:1] FROM sal_emp WHERE
sal_emp.name = 'Bill';
-- clean up (you must remove the children first)
DROP TABLE sal_emp;
DROP TABLE capitals;
DROP TABLE cities;