b) Sunita is not clear about the difference between the following two statements: i) SELECT (24*8 ); ii) SELECT (24*8 ) from empl; Help her understand the difference between these two statements. c) When a PRIMARY KEY constraint is included in a table, what other constraints does this imply? d) Given the following CREATE TABLE command, identify foreign key constraints and their complete details. (i.e, the parent table, child table, field name, restriction etc.) CREATE TABLE lego_composer ( Construction int(11) NOT NULL, Brique int(11) NOT NULL, Nombre integer NOT NULL Default 1, CONSTRAINT Construction_composer FOREIGN KEY (construction) REFERENCES LEGO_CONSTRUCTION(id) ON DELETE RESTRICT ON UPDATE CASCADE, CONSTRAINT brique_composer FOREIGN KEY (brique) REFERENCES LEGO_BRIQUE(id) ON DELETE RESTRICT ON UPDATE CASCADE, PRIMARY KEY (Construction, Brique) );
Posted on: Sat, 01 Feb 2014 07:28:14 +0000
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