Database normalization is the cornerstone of database theory. Once a database is normalized, relationships between the data in multiple tables must be established. A hefty part of designing a ...

See how to join two data sets by one or more common columns using base R’s merge function, dplyr join functions, and the speedy data.table package. R has a number of quick, elegant ways to join data ...

Please note: This item is from our archives and was published in 2003. It is provided for historical reference. The content may be out of date and links may no longer function. Q. I often recruit ...

In formulating the tenets of relational theory, issues anent to order were explicitly addressed. These relational theory tenets included defining a relational database so that it need have no concern ...