Similarly for any of the foreign key constraints which are many-to-one or many-to-many.Each month, over 50 million developers come to Stack Overflow to learn, share their knowledge, and build their careers.To have many actors belonging to many movies, you will need a seperate relations table.I have also found some great ER Diagram Examples using Lucidchart and their site is...Browse other questions tagged mysql database-design rdbms relationship or ask your own question.The role table would hold various positions - eg, director, producer, star, extra, grip, editor. and it would look more like.The physical ER model is normally developed to be instantiated as a database.
An entity-relationship diagram is a specialized graphic form that illustrates the relationships between entities in a database.You may use an auto increment key for ease of use in joins and such, but you should have a unique constraint on the uniqueness fields anyway.The first one was the film and it attributes or characteristics.Using a surrogate key (primary key) for tables is generally a good idea.Taking it a step further, sometimes directors are also actors, and vice-versa.
Model Access Data Model using ERD What is an Entity Relationship Diagram.You need to insert in reverse order (and this is where auto increment keys can be an even bigger PITA - if you can add date of birth or something into the Actors and Directors table, then a unique constraint can make it easier).E-R Diagram for Hotel management system By Lankika Wijewardana.
Each movie can be any number of genres (comedy and horror, for example).Thank you so much for your indepth responce Greg, much appreciated mate.
This can also include crew members (in case you want to track who the 2nd Junior Assistant Dolly Grip was).So rather than even have director and actor tables, you could have a single person table, and join that table in using a role table.In this case, having a year table is unnecessary, since there are no other attributes about a year, besides the year itself, that you would store.Instead of having a directors and actors table, just have one table of people.
Once this is set up, it is easy to query and find everything a given person has done, or everything a person has done as a director, or everyone who has ever directed a movie, or all the people involved with one specific movie.I realize your question has already been answered, however I wanted to point you to.It seems like what you need is more of a conceptual start here.Also, your genre, director, and actor tables need their own unique IDs.
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