Using three column as the primary key : Primary Key « Key « SQL / MySQL






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Using three column as the primary key

     
mysql>
mysql>
mysql> CREATE   TABLE DIPLOMAS
    ->         (STUDENT     INTEGER NOT NULL,
    ->          COURSE      INTEGER NOT NULL,
    ->          DDATE       DATE NOT NULL,
    ->          SUCCESSFUL  CHAR(1),
    ->          LOCATION    VARCHAR(50),
    ->          PRIMARY KEY (STUDENT, COURSE, DDATE));
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql>
mysql> drop table diplomas;
Query OK, 0 rows affected (0.00 sec)








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