Create a multiple-column primary key using UNIQUE, if the columns are declared NOT NULL : Primary Key « Key « SQL / MySQL






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Create a multiple-column primary key using UNIQUE, if the columns are declared NOT NULL

     
mysql>
mysql> CREATE TABLE people
    -> (
    ->     last_name  CHAR(30) NOT NULL,
    ->     first_name CHAR(30) NOT NULL,
    ->     UNIQUE (last_name, first_name)
    -> );
Query OK, 0 rows affected (0.00 sec)

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








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