diff --git a/src/tutorial/advanced.source b/src/tutorial/advanced.source index 0c04a98325462c0cad47a09605f2e7ad457de123..7dd3ab1bb40f32f46eea89b5220dd750a9d613a5 100644 --- a/src/tutorial/advanced.source +++ b/src/tutorial/advanced.source @@ -6,13 +6,13 @@ -- -- Copyright (c) 1994, Regents of the University of California -- --- $Id: advanced.source,v 1.4 2001/09/02 23:27:50 petere Exp $ +-- $Id: advanced.source,v 1.5 2002/04/11 21:18:50 tgl Exp $ -- --------------------------------------------------------------------------- ----------------------------- -- Inheritance: --- S table can inherit from zero or more tables. A query can reference +-- A 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. ----------------------------- @@ -41,19 +41,19 @@ INSERT INTO capitals VALUES ('Madison', 1.913E+5, 845, 'WI'); SELECT * FROM cities; SELECT * FROM capitals; --- like before, a regular query references rows of the base table only - -SELECT name, altitude -FROM cities -WHERE altitude > 500; - --- on the other hand, you can find all cities, including capitals, that --- are located at an altitude of 500 'ft or higher by: +-- You can find all cities, including capitals, that +-- are located at an altitude of 500 ft or higher by: SELECT c.name, c.altitude -FROM cities* c +FROM cities c WHERE c.altitude > 500; +-- To scan rows of the parent table only, use ONLY: + +SELECT name, altitude +FROM ONLY cities +WHERE altitude > 500; + -- clean up (you must remove the children first) DROP TABLE capitals;