La chiave primaria di una tabella può essere definita all'interno della DDL della tabella.
Nella seguente istruzione viene definita la colonna ID_CLIENTE come chiave primaria attraverso la clausola
PRIMARY KEY:
CREATE TABLE CLIENTI (ID_CLIENTE NUMBER PRIMARY KEY, NOME VARCHAR2(30),
COGNOME VARCHAR2(30));
Oppure si può utilizzare l'istruzione ALTER TABLE che, in questo esempio, definisce la chiave primaria, denominata PK_CLIENTI ,
della tabella clienti sulla colonna id_cliente:
sql>
ALTER TABLE CLIENTI ADD CONSTRAINT PK_CLIENTI
PRIMARY KEY (ID_CLIENTE);
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A good scientist is a person with original ideas.
A good engineer is a person who makes a design that works with as few original ideas as possible. There are no prima donnas in engineering. Freeman Dyson
A good scientist is a person with original ideas.
A good engineer is a person who makes a design that works with as few original ideas as possible. There are no prima donnas in engineering. Freeman Dyson
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