Applications often need to access databases to store and retrieve various kinds of data. A database (http://en.wikipedia.org/wiki/Database) is an organized collection of data. Although there are many kinds of databases (such as hierarchical, object-oriented, and relational), relational databases, which organize data into tables that can be related to each other, are common.
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In a relational database, each row stores a single item (such as an employee) and each column stores a single item attribute (such as ...
