create table中的小问题,3ks
CREATE TABLE
[ database_name.[ owner ] .| owner.] table_name
( { < column_definition >
| column_name AS computed_column_expression
| < table_constraint > ::= [ CONSTRAINT constraint_name ] }
| [ { PRIMARY KEY | UNIQUE } [ ,...n ]
)
看第7行,[ { PRIMARY KEY | UNIQUE } [ ,...n ]怎么用??给个例子吧,谢谢:)