Java and Database Connectivity

Other things in SQL which we may use

Views

named joins

• can be selected from and joined just like tables
• can't be written to
• not supported by all databases

    create view myview as select ...

Transactions

Groups of statements which are executed together, such that if any one of them fails, the effects of all of them can be reversed.

    begin
    delete from attendance where workshop = 7;
    delete from workshop where workshop = 7;
    commit;

Permisssions

• control who can do what to what
• very important, particularly for Web databases
• not supported by all databases

    grant select, insert, update, delete 
       on venue 
       to simon;

    revoke update, delete 
        on attendance
      from simon;

    revoke insert, update, delete 
        on venue, attendee, attendance 
      from public;
    

There's lots more in SQL but we won't have time today.

Full text of this presentation | Table of Contents | No Frames Author: Simon Brooke | Copyright © 2001 Simon Brooke Slide 61 of 95

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