We began this chapter with a definition of a view, and you learned that it is a virtual table that does not contain or store data. Views are useful for several reasons—they provide a means for you to work with data from multiple tables, they help enforce data integrity, and they help keep data secure or confidential.

We then discussed the three types of views: data, aggregate, and validation. You learned that each type of view can be based on one or more tables, other views, or a combination of both. Your RDBMS will rebuild and repopulate a view every time you access it, using the most current data from the view's base tables. As you now know, there must be relationships between tables in a multitable view (thus making the view's ...

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